title: Critical Hardy inequalities

abstract:
  We prove a range of critical Hardy inequalities and uncertainty type
principles on one of most general subclasses of nilpotent Lie groups, namely
the class of homogeneous groups. Moreover, we establish a new type of critical
Hardy inequality and prove Hardy-Sobolev type inequalities. Most of the
obtained estimates are new already for the case of $\mathbb R^{n}$. For
example, for any $f\in C_{0}^{\infty}(\mathbb{R}^{n}\backslash\{0\})$ our
results imply the range of critical Hardy inequalities of the form $$\qquad
\underset{R>0}{\sup}\left\|\frac{f-f_{R}}{|x|^{\frac{n}{p}}{\log}\frac{R}{|x|}}\right\|_{L^{p}(\mathbb{R}^{n})}\leq
\frac{p}{p-1}\left\| \frac{1}{|x|^{\frac{n}{p}-1}} \nabla
f\right\|_{L^{p}(\mathbb{R}^{n})},\quad 1<p<\infty,$$ where
$f_{R}=f(R\frac{x}{|x|})$, with sharp constant $\frac{p}{p-1}$, recovering the
known cases of $p=n$ and $p=2$. Moreover, our results also imply a new type of
a critical Hardy inequality of the form
$$\left\|\frac{f}{|x|}\right\|_{L^{n}(\mathbb{R}^{n})}\leq
n\left\|(\log|x|)\nabla f\right\|_{L^{n}\mathbb{R}^{n})}, $$ for all $f\in
C_{0}^{\infty}(\mathbb{R}^{n}\backslash\{0\}),$ where the constant $n$ is
sharp. However, homogeneous groups provide a perfect degree of generality to
talk about such estimates without using specific properties of $\mathbb R^n$ or
of the Euclidean distance.


title: Strongly magnetized accretion discs require poloidal flux

abstract:
  Motivated by indirect observational evidence for strongly magnetized
accretion discs around black holes, and the novel theoretical properties of
such solutions, we investigate how a strong magnetization state can develop and
persist. To this end, we perform local simulations of accretion discs with an
initially purely toroidal magnetic field of equipartition strength. We
demonstrate that discs with zero net vertical magnetic flux and realistic
boundary conditions cannot sustain a strong toroidal field. However, a magnetic
pressure-dominated disc can form from an initial configuration with a
sufficient amount of net vertical flux and realistic boundary conditions. Our
results suggest that poloidal flux is a necessary prerequisite for the
sustainability of strongly magnetized accretion discs.


title: Precursors, Gauge Invariance, and Quantum Error Correction in AdS/CFT

abstract:
  A puzzling aspect of the AdS/CFT correspondence is that a single bulk
operator can be mapped to multiple different boundary operators, or precursors.
By improving upon a recent model of Mintun, Polchinski, and Rosenhaus, we
demonstrate explicitly how this ambiguity arises in a simple model of the field
theory. In particular, we show how gauge invariance in the boundary theory
manifests as a freedom in the smearing function used in the bulk-boundary
mapping, and explicitly show how this freedom can be used to localize the
precursor in different spatial regions. We also show how the ambiguity can be
understood in terms of quantum error correction, by appealing to the
entanglement present in the CFT. The concordance of these two approaches
suggests that gauge invariance and entanglement in the boundary field theory
are intimately connected to the reconstruction of local operators in the dual
spacetime.


title: Naturalizing Supersymmetry with a Two-Field Relaxion Mechanism

abstract:
  We present a supersymmetric version of a two-field relaxion model that
naturalizes tuned versions of supersymmetry. This arises from a relaxion
mechanism that does not depend on QCD dynamics and where the relaxion potential
barrier height is controlled by a second axion-like field. During the
cosmological evolution, the relaxion rolls with a nonzero value that breaks
supersymmetry and scans the soft supersymmetric mass terms. Electroweak
symmetry is broken after the soft masses become of order the supersymmetric
Higgs mass term and causes the relaxion to stop rolling for superpartner masses
up to $\sim 10^9$ GeV. This can explain the tuning in supersymmetric models,
including split-SUSY models, while preserving the QCD axion solution to the
strong CP problem. Besides predicting two very weakly-coupled axion-like
particles, the supersymmetric spectrum may contain an extra Goldstino, which
could be a viable dark matter candidate.


title:
Halo and Subhalo Demographics with Planck Cosmological Parameters:
  Bolshoi-Planck and MultiDark-Planck Simulations

abstract:
  We report and provide fitting functions for the abundance of dark matter
halos and subhalos as a function of mass, circular velocity, and redshift from
the new Bolshoi-Planck and MultiDark-Planck $\Lambda$CDM cosmological
simulations, based on the Planck cosmological parameters. We also report the
halo mass accretion rates, which may be connected with galaxy star formation
rates. We show that the higher cosmological matter density of the Planck
parameters compared with the WMAP parameters leads to higher abundance of
massive halos at high redshifts. We find that the median halo spin parameter
$\lambda_{\rm B} = J(2M_{\rm vir}R_{\rm vir}V_{\rm vir})^{-1}$ is nearly
independent of redshift, leading to predicted evolution of galaxy sizes that is
consistent with observations, while the significant decrease with redshift in
median $\lambda_{\rm P} = J|E|^{-1/2}G^{-1}M^{-5/2}$ predicts more decrease in
galaxy sizes than is observed. Using the Tully-Fisher and Faber-Jackson
relations between galaxy velocity and mass, we show that a simple model of how
galaxy velocity is related to halo maximum circular velocity leads to
increasing overprediction of cosmic stellar mass density as redshift increases
beyond redshifts $z\sim1$, implying that such velocity-mass relations must
change at redshifts $z>1$. By making a realistic model of how observed galaxy
velocities are related to halo circular velocity, we show that recent optical
and radio observations of the abundance of galaxies are in good agreement with
our $\Lambda$CDM simulations. Our halo demographics are based on updated
versions of the \rockstar\ and \ctrees\ codes, and this paper includes
appendices explaining all of their outputs. This paper is an introduction to a
series of related papers presenting other analyses of the Bolshoi-Planck and
MultiDark-Planck simulations.


title:
How Spirals and Gaps Driven by Companions in Protoplanetary Disks Appear
  in Scattered Light at Arbitrary Viewing Angles

abstract:
  Direct imaging observations of protoplanetary disks at near-infrared (NIR)
wavelengths have revealed structures of potentially planetary origin.
Investigations of observational signatures from planet-induced features have so
far focused on disks viewed face-on. Combining 3D hydrodynamics and radiative
transfer simulations, we study how the appearance of the spiral arms and the
gap produced in a disk by a companion varies with inclination and position
angle in NIR scattered light. We compare the cases of a $3M_{\rm J}$ and a
$0.1M_{\odot}$ companion, and make predictions suitable for testing with
Gemini/GPI, VLT/NACO/SPHERE, and Subaru/HiCIAO/SCExAO. We find that the two
trailing arms produced by an external perturber can have a variety of
morphologies in inclined systems - they may appear as one trailing arm; two
trailing arms on the same side of the disk; or two arms winding in opposite
directions. The disk ring outside a planetary gap may also mimic spiral arms
when viewed at high inclinations. We suggest potential explanations for the
features observed in HH 30, HD 141569 A, AK Sco, HD 100546, and AB Aur. We
emphasize that inclined views of companion-induced features cannot be converted
into face-on views using simple and commonly practiced image deprojections.


title: On Ellipsoidal Collapse and Primordial Black-Hole Formation

abstract:
  We reinvestigate gravitational ellipsoidal collapse with special focus on its
impact on primordial black-hole formation. For a generic model we demonstrate
that the abundance and energy density of the produced primordial black holes
will be significantly decreased when the non-sphericity of the overdensities is
taken into account.


title: A White Paper on keV Sterile Neutrino Dark Matter

abstract:
  We present a comprehensive review of keV-scale sterile neutrino Dark Matter,
collecting views and insights from all disciplines involved - cosmology,
astrophysics, nuclear, and particle physics - in each case viewed from both
theoretical and experimental/observational perspectives. After reviewing the
role of active neutrinos in particle physics, astrophysics, and cosmology, we
focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we
first review the physics motivation for sterile neutrino Dark Matter, based on
challenges and tensions in purely cold Dark Matter scenarios. We then round out
the discussion by critically summarizing all known constraints on sterile
neutrino Dark Matter arising from astrophysical observations, laboratory
experiments, and theoretical considerations. In this context, we provide a
balanced discourse on the possibly positive signal from X-ray observations.
Another focus of the paper concerns the construction of particle physics
models, aiming to explain how sterile neutrinos of keV-scale masses could arise
in concrete settings beyond the Standard Model of elementary particle physics.
The paper ends with an extensive review of current and future astrophysical and
laboratory searches, highlighting new ideas and their experimental challenges,
as well as future perspectives for the discovery of sterile neutrinos.


title: A search for minimal 4d N=1 SCFT

abstract:
  We discuss a candidate for a minimal interacting 4-dimensional N=1
superconformal field theory (SCFT). The model contains a chiral primary
operator u satisfying the chiral ring relation u^2=0, and its scaling dimension
is \Delta(u)=1.5. The model is derived by turning on a N=1 preserving
deformation of N=2 A2 Argyres-Douglas theory. The central charges are given by
(a,c)=(263/768, 271/768) ~ (0.342,0.353). There is no moduli space of vacua, no
flavor symmetry, and the chiral ring is finite.


title: Axion String Dynamics I: 2+1D

abstract:
  If the axion exists and if the initial axion field value is uncorrelated at
causally disconnected points, then it should be possible to predict the
efficiency of cosmological axion production, relating the axionic dark matter
density to the axion mass. The main obstacle to making this prediction is
correctly treating the axion string cores. We develop a new algorithm for
treating the axionic string cores correctly in 2+1 dimensions. When the axionic
string cores are given their full physical string tension, axion production is
about twice as efficient as in previous simulations. We argue that the string
network in 2+1 dimensions should behave very differently than in 3+1
dimensions, so this result cannot be simply carried over to the physical case.
We outline how to extend our method to 3+1D axion string dynamics.


title: The origin of compact galaxies with anomalously high black hole masses

abstract:
  Observations of local galaxies harbouring supermassive black holes (BHs) of
anomalously high mass, M_BH, relative to their stellar mass, M_star, appear to
be at odds with simple models of the co-evolution between galaxies and their
central BHs. We study the origin of such outliers in a Lambda cold dark matter
context using the EAGLE cosmological, hydrodynamical simulation. We find 15
'M_BH(M_star)-outlier' galaxies, defined as having M_BH more than 1.5 dex above
the median M_BH(M_star) relation in the simulation, M_{BH,med}. All
M_BH(M_star)-outliers are satellite galaxies, typically with M_star ~ 10^10
M_sun and M_BH ~ 10^8 M_sun. They have all become outliers due to a combination
of tidal stripping of their outer stellar component acting over several Gyr and
early formation times leading to rapid BH growth at high redshift, with the
former mechanism being most important for 67 per cent of these outliers. The
same mechanisms also cause the M_BH(M_star)-outlier satellites to be amongst
the most compact galaxies in the simulation, making them ideal candidates for
ultracompact dwarf galaxy progenitors. The 10 most extreme central galaxies
found at z=0 (with log_{10}(M_BH/M_{BH,med}) in [1.2, 1.5]) grow rapidly in
M_BH to lie well above the present-day M_BH-M_star relation at early times (z >
2), and either continue to evolve parallel to the z=0 relation or remain
unchanged until the present day, making them 'relics' of the high-redshift
universe. This high-z formation mechanism may help to explain the origin of
observed M_BH(M_star)-outliers with extended dark matter haloes and undisturbed
morphologies.


title:
Quiet Sun H\alpha\ Transients and Corresponding Small-Scale Transition
  Region and Coronal Heating

abstract:
  Rapid Blue- and Red-shifted Excursions (RBEs and RREs) are likely to be the
on-disk counterparts of Type II spicules. Recently, heating signatures from
RBEs/RREs have been detected in IRIS slit-jaw images dominated by
transition-region lines around network patches. Additionally, signatures of
Type II spicules have been observed in AIA diagnostics. The full-disk,
ever-present nature of the AIA diagnostics should provide us with sufficient
statistics to directly determine how important RBEs and RREs are to the heating
of the transition region and corona. We find, with high statistical
significance, that at least 11% of the low-coronal brightenings detected in a
quiet-Sun region in 304, can be attributed to either RBEs or RREs as observed
in H\alpha, and a 6% match of 171 detected events to RBEs or RREs with very
similar statistics for both types of H\alpha\ features. We took a statistical
approach that allows for noisy detections in the coronal channels and provides
us with a lower, but statistical significant, bound. Further, we consider
matches based on overlapping features in both time and space, and find strong
visual indications of further correspondence between coronal events and
co-evolving but non-overlapping, RBEs and RREs.


title:
Baryon number violation in supersymmetry: Neutron-antineutron
  oscillations as a probe beyond the LHC

abstract:
  We summarize the current status of baryon number violation in supersymmetry
and provide prospects for going beyond the present reach by means of a new
search for neutron-antineutron oscillations. The main motivation is the
recently proposed neutron-antineutron oscillation experiment at the European
Spallation Source in Lund, Sweden, which is projected to be able to improve the
current bound on the transition probability in the quasi-free regime by three
orders of magnitude. We consider various processes involving superpartners that
give rise to neutron-antineutron oscillations and extract the corresponding
simplified models, including only the most relevant superpartners and
couplings. In terms of these models we recast and determine the exclusion
limits from LHC searches as well as from searches for flavor transitions, CP
violation and di-nucleon decays. We find that, for certain regions of the
parameter space, the proposed neutron-antineutron experiment has a reach that
goes beyond all other experiments, as it can probe gluino and squark masses in
the multi-TeV range.


title: Constraining New Physics Models with Isotope Shift Spectroscopy

abstract:
  Isotope shifts of transition frequencies in atoms constrain generic long- and
intermediate-range interactions. We focus on new physics scenarios that can be
most strongly constrained by King Linearity Violation such as models with B-L
vector bosons, Higgs portal and chameleon. With the anticipated precision, King
Linearity Violation has the potential to set the strongest laboratory bounds on
these models in some regions of parameter space. Furthermore, we show that this
method can probe the couplings relevant for the protophobic interpretation of
the recently reported Be anomaly. We extend the formalism to include an
arbitrary number of transitions and isotope pairs and fit the new physics
coupling to the currently available isotope shift measurements.


title: ALMA Finds Dew Drops in the Dusty Spider's Web

abstract:
  We present 0."5 resolution ALMA detections of the observed 246GHz continuum,
[CI]^3P_2-^3P_1 fine structure line ([CI]2-1), CO(7-6) and H2O lines in the
z=2.161 radio galaxy MRC1138-262, the 'Spiderweb Galaxy'. We detect strong
[CI]2-1 emission both at the position of the radio core, and in a second
component ~4kpc away from it. The 1100km/s broad [CI]2-1 line in this latter
component, combined with its H2 mass of 1.6x10^10Msun implies this emission
must come from a compact region <60pc, possibly containing a second AGN. The
combined H2 mass derived for both objects using the [CI]2-1 emission is
3.3x10^10Msun. The total CO(7-6)/[CI]2-1 line flux ratio of 0.2 suggests a low
excitation molecular gas reservoir and/or enhanced atomic carbon in cosmic-ray
dominated regions. We detect spatially-resolved H2O 2_{11}-2_{02} emission -
for the first time in a high-z un-lensed galaxy - near the outer radio lobe to
the east, and near the bend of the radio jet to the west of the radio galaxy.
No underlying 246GHz continuum emission is seen at either position. We suggest
that the H2O emission is excited in the cooling region behind slow (10-40km/s)
shocks in dense molecular gas (10^{3-5} cm^-3). The extended water emission is
likely evidence of the radio jet's impact in cooling and forming molecules in
the post-shocked gas in the halo and inter-cluster gas similar to what is seen
in low-z clusters and other high-z radio galaxies. These observations imply
that the passage of the radio jet in the interstellar and inter-cluster medium
not only heats gas to high temperatures as is commonly assumed or found in
simulations, but also induces cooling and dissipation which can lead to
substantial amounts of cold dense molecular gas. The formation of molecules and
strong dissipation in the halo gas of MRC1138-262 may explain both the extended
diffuse molecular gas and young stars observed around MRC1138-262.


title:
Mass and Metallicity Requirement in Stellar Models for Galactic Chemical
  Evolution Applications

abstract:
  We used a one-zone chemical evolution model to address the question of how
many masses and metallicities are required in grids of massive stellar models
in order to ensure reliable galactic chemical evolution predictions. We used a
set of yields that includes seven masses between 13 and 30 Msun, 15
metallicities between 0 and 0.03 in mass fraction, and two different remnant
mass prescriptions. We ran several simulations where we sampled subsets of
stellar models to explore the impact of different grid resolutions. Stellar
yields from low- and intermediate-mass stars and from Type Ia supernovae have
been included in our simulations, but with a fixed grid resolution. We compared
our results with the stellar abundances observed in the Milky Way for O, Na,
Mg, Si, Ca, Ti, and Mn. Our results suggest that the range of metallicity
considered is more important than the number of metallicities within that
range, which only affects our numerical predictions by about 0.1 dex. We found
that our predictions at [Fe/H] < -2 are very sensitive to the metallicity range
and the mass sampling used for the lowest metallicity included in the set of
yields. Variations between results can be as high as 0.8 dex, for any remnant
mass prescription. At higher [Fe/H], we found that the required number of
masses depends on the element of interest and on the remnant mass prescription.
With a monotonic remnant mass prescription where every model explodes as a
core-collapse supernova, the mass resolution induces variations of 0.2 dex on
average. But with a remnant mass prescription that includes islands of
non-explodability, the mass resolution can cause variations of about 0.2 to 0.7
dex depending on the choice of metallicity range. With such a prescription,
explosive or non-explosive models can be missed if not enough masses are
selected, resulting in over- or under-estimations of the mass ejected by
massive stars.


title: Entanglement entropy in top-down models

abstract:
  We explore holographic entanglement entropy in ten-dimensional supergravity
solutions. It has been proposed that entanglement entropy can be computed in
such top-down models using minimal surfaces which asymptotically wrap the
compact part of the geometry. We show explicitly in a wide range of examples
that the holographic entanglement entropy thus computed agrees with the
entanglement entropy computed using the Ryu-Takayanagi formula from the
lower-dimensional Einstein metric obtained from reduction over the compact
space. Our examples include not only consistent truncations but also cases in
which no consistent truncation exists and Kaluza-Klein holography is used to
identify the lower-dimensional Einstein metric. We then give a general proof,
based on the Lewkowycz-Maldacena approach, of the top-down entanglement entropy
formula.


title: Dark Matter Trapping by Stellar Bars: The Shadow Bar

abstract:
  We investigate the complex interactions between the stellar disc and the
dark-matter halo during bar formation and evolution using N-body simulations
with fine temporal resolution and optimally chosen spatial resolution. We find
that the forming stellar bar traps dark matter in the vicinity of the stellar
bar into bar-supporting orbits. We call this feature the shadow bar. The shadow
bar modifies both the location and magnitude of the angular momentum transfer
between the disc and dark matter halo and adds 10 per cent to the mass of the
stellar bar over 4 Gyr. The shadow bar is potentially observable by its density
and velocity signature in spheroid stars and by direct dark matter detection
experiments. Numerical tests demonstrate that the shadow bar can diminish the
rate of angular momentum transport from the bar to the dark matter halo by more
than a factor of three over the rate predicted by dynamical friction with an
untrapped dark halo, and thus provides a possible physical explanation for the
observed prevalence of fast bars in nature.


title:
Direct detection of precursors of gas giants formed by gravitational
  instability with the Atacama Large Millimetre/sub-millimetre Array

abstract:
  Phases of gravitational instability are expected in the early phases of disk
evolution, when the disk mass is still a substantial fraction of the mass of
the star. Disk fragmentation into sub-stellar objects could occur in the cold
exterior part of the disk. Direct detection of massive gaseous clumps on their
way to collapse into gas giant planets would offer an unprecedented test of the
disk instability model. Here we use state-of-the-art 3D radiation-hydro
simulations of disks undergoing fragmentation into massive gas giants,
post-processed with the RADMC-3D ray-tracing code to produce dust continuum
emission maps. These are then fed into the Common Astronomy Software
Applications (CASA) ALMA simulator. The synthetic maps show that both overdense
spiral arms and actual clumps at different stages of collapse can be detected
with the Atacama Large Millimetre/sub-millimetre Array (ALMA) in the full
configuration at the distance of the Ophiuchus star forming region (125 pc).
The detection of clumps is particularly effective at shorter wavelengths (690
GHz) combining two resolutions with multi-scale clean. Furthermore, we show
that a flux-based estimate of the mass of a protoplanetary clump can be from
comparable to a factor of 3 higher than the gravitationally bound clump mass.
The estimated mass depends on the assumed opacity, and on the gas temperature,
which should be set using the input of radiation-hydro simulations. We conclude
that ALMA has the capability to detect "smoking gun" systems that are a
signpost of the disk instability model for gas giant planet formation.


title: A second quantized approach to the Rabi problem

abstract:
  In the present work the Rabi Problem, involving the response of a spin 1/2
particle subjected to a magnetic field, is considered in a second quantized
approach. In this concrete physical scenario, we show that the second
quantization procedure can be applied directly in a non-covariant theory. The
proposed development explicits not only the relation between the full quantum
treatment of the problem and the semiclassical Rabi model, but also the
connection of these approaches with the Jaynes-Cummings model. The consistency
of the method is checked in the semiclassical limit. The treatment is then
extended to the matter component of the Rabi problem so that the Schr\"odinger
equation is directly quantized. Considering the spinorial field, the appearance
of a negative energy sector implies a specific identification between
Schr\"odinger's and Maxwell's theories. The generalized theory is consistent,
strictly quantum and non-relativistic.


title: The light asymptotic limit of conformal blocks in Toda field theory

abstract:
  We compute the light asymptotic limit of $A_{n-1}$ Toda conformal blocks by
using the AGT correspondence. We show that for certain class of CFT blocks the
corresponding Nekrasov partition functions in this limit are simplified
drastically being represented as a sum of a restricted class of Young diagrams.
In the particular case of $A_{2}$ Toda we also compute the corresponding
conformal blocks using conventional CFT techniques finding a perfect agreement
with the results obtained from the Nekrasov partition functions.


title:
The Klein-Gordon-Fock equation in the curved spacetime of the
  Kerr-Newman (anti) de Sitter black hole

abstract:
  Exact solutions of the Klein-Gordon-Fock (KGF) general relativistic equation
that describe the dynamics of a massive, electrically charged scalar particle
in the curved spacetime geometry of a charged, rotating Kerr-Newman-(anti) de
Sitter black hole are investigated. In the general case of a rotating, charged,
cosmological black hole the solution of the KGF equation with the method of
separation of variables results in Fuchsian differential equations for the
radial and angular parts which contain more than three finite singularities and
thereby generalise the Heun differential equations (HE). For particular values
of the physical parameters (i.e mass of the scalar particle) these Fuchsian
equations reduce to Heun equations and the solutions are expressed in terms of
Heun functions. For other values of the parameters some of the extra singular
points are false singular points. We derive the conditions on the coefficients
of the generalised Fuchsian equation such that a singular point is a false
point. In such a case the exact solution of the Fuchsian equation can in
principle be simplified and expressed in terms of Heun functions. We also
derive the exact solutions of the radial and angular equations for a massive
scalar (charged) particle in the Kerr-Newman spacetime. The analytic solutions
are expressed in terms of confluent Heun functions. Moreover, we derived the
constraints on the parameters of the theory such that the solution simplifies
and expressed in terms of confluent Kummer hypergeometric functions. We also
investigate the radial solutions in the KN case in the regions near the event
horizon and far from the black hole. Finally, we construct several expansions
of the solutions of the HE in terms of generalised hypergeometric functions of
Lauricella-Appell.


title: Evolution of dispersion in the cosmic deuterium abundance

abstract:
  Deuterium is created during Big Bang Nucleosynthesis, and, in contrast to the
other light stable nuclei, can only be destroyed thereafter by fusion in
stellar interiors. In this paper we study the cosmic evolution of the deuterium
abundance in the interstellar medium and its dispersion using realistic galaxy
evolution models. We find that models that reproduce the observed metal
abundance are compatible with observations of the deuterium abundance in the
local ISM and z ~ 3 absorption line systems. In particular, we reproduce the
low astration factor which we attribute to a low global star formation
efficiency. We calculate the dispersion in deuterium abundance arising from
different structure formation histories in different parts of the Universe. Our
model also predicts an extremely tight correlation between deuterium and metal
abundances which could be used to measure the primordial deuterium abundance.


title: The Baryonic Tully-Fisher Relation cares about the Galaxy Sample

abstract:
  The Baryonic Tully-Fisher relation (BTFR) is a clear manifestation of the
underlying physics of galaxy formation. As such, it is used to constrain and
test galaxy formation and evolution models. Of particular interest, apart from
the slope of the relation, is its intrinsic scatter. In this paper, we use the
EAGLE simulation to study the dependence of the BTFR on the size of the
simulated galaxy sample. The huge number of datapoint available in the
simulation is indeed not available with current observations. Observational
studies that computed the BTFR used various (small) size samples with the only
obligation to have galaxies spanning over a large range of masses and rotation
rates. Accordingly, to compare observational and theoretical results, we build
a large number of various size datasets using the same criterion and derive the
BTFR for all of them. Unmistakably, their is an effect of the number of
galaxies used to derive the relation. The smaller the number, the larger the
standard deviation around the average slope and intrinsic scatter of a given
size sample of galaxies. This observation allows us to alleviate the tensions
between observational measurements and LCDM predictions. Namely, the size of
the observational samples adds up to the complexity in comparing observed and
simulated relations to discredit or confirm LCDM. Similarly, samples, even
large, that do not reflect the galaxy distribution give on average biased
results. Large size samples reproducing the underlying distribution of galaxies
constitute a supplementary necessity to compare efficiently observations and
simulations.


title: Triply-resonant Continuous Wave Parametric Source with a Microwatt Pump

abstract:
  We demonstrate a nanophotonic parametric light source with a record high
normalized conversion efficiency of $3\times 10^6\, W^{-2}$, owing to
resonantly enhanced four wave mixing in coupled high-Q photonic crystal
resonators. The rate of spontaneously emitted photons reaches 14 MHz.


title:
On new inequalities of Hermite-Hadamard type for functions whose fourth
  derivative absolute values are quasi-convex with applications

abstract:
  We establish some new inequalities of Hermite-Hadamard type for functions
whose fourth derivatives absolute values are quasi-convex. Further, we give new
identity.Using this new identity, we establish similar inequalities for
left-hand side of Hermite-Hadamard result.Also, we present applications to
special means.


title:
Cutset Width and Spacing for Reduced Cutset Coding of Markov Random
  Fields

abstract:
  In this paper we explore tradeoffs, regarding coding performance, between the
thickness and spacing of the cutset used in Reduced Cutset Coding (RCC) of a
Markov random field image model. Considering MRF models on a square lattice of
sites, we show that under a stationarity condition, increasing the thickness of
the cutset reduces coding rate for the cutset, increasing the spacing between
components of the cutset increases the coding rate of the non-cutset pixels,
though the coding rate of the latter is always strictly less than that of the
former. We show that the redundancy of RCC can be decomposed into two terms, a
correlation redundancy due to coding the components of the cutset
independently, and a distribution redundancy due to coding the cutset as a
reduced MRF. We provide analysis of these two sources of redundancy. We present
results from numerical simulations with a homogeneous Ising model that bear out
the analytical results. We also present a consistent estimation algorithm for
the moment-matching reduced MRF on the cutset.


title:
New Hermite-Hadamard and Simpson Type Inequalities For Harmonically
  $(s,m)$-convex functions in Second Sense

abstract:
  In \cite{II}, authors introduced the concept of harmonically $(s,m)$-convex
functions in second sense which unifies different type of convexities and is
more general notion of Harmonic convexity. In this paper, authors obtain new
estimates on generalization of Hermite-Hadamard and Simpson type inequalities
for this larger class of functions.


title:
Cross-correlation of the cosmic 21-cm signal and Lyman Alpha Emitters
  during reionization

abstract:
  Interferometry of the cosmic 21-cm signal is set to revolutionize our
understanding of the Epoch of Reionization (EoR), eventually providing 3D maps
of the early Universe. Initial detections however will be low signal-to-noise,
limited by systematics. To confirm a putative 21-cm detection, and check the
accuracy of 21-cm data analysis pipelines, it would be very useful to
cross-correlate against a genuine cosmological signal. The most promising
cosmological signals are wide-field maps of Lyman alpha emitting galaxies
(LAEs), expected from the Subaru Hyper-Suprime Cam (HSC) Ultra-Deep field. Here
we present estimates of the correlation between LAE maps at z~7 and the 21-cm
signal observed by both the Low Frequency Array (LOFAR) and the planned Square
Kilometer Array Phase 1 (SKA1). We adopt a systematic approach, varying both:
(i) the prescription of assigning LAEs to host halos; and (ii) the large-scale
structure of neutral and ionized regions (i.e. EoR morphology). We find that
the LAE-21cm cross-correlation is insensitive to (i), thus making it a robust
probe of the EoR. A 1000h observation with LOFAR would be sufficient to
discriminate at >1 standard deviation a fully ionized Universe from one with a
mean neutral fraction of xHI~0.50, using the LAE-21cm cross-correlation
function on scales of R~3-10 Mpc. Unlike LOFAR, whose detection of the LAE-21cm
cross-correlation is limited by noise, SKA1 is mostly limited by ignorance of
the EoR morphology. However, the planned 100h wide-field SKA1-Low survey will
be sufficient to discriminate an ionized Universe from one with xHI~0.25, even
with maximally pessimistic assumptions.


title: Probing New Physics with Isotope Shift Spectroscopy

abstract:
  We investigate the potential to probe physics beyond the Standard Model with
isotope shift measurements of optical atomic clock transitions. We first derive
the reach for generic new physics above the GeV scale at the effective field
theory level, as well as estimate the limits on possible new spin-independent
forces mediated by sub-GeV states coupled to electrons and neutrons. We also
study the weak force and show that isotope shifts could provide strong
constraints on the $Z^0$ couplings to valence quarks, which complement
precision observables at LEP and atomic parity violation experiments. Finally,
motivated by recent experimental hints of a new 750 GeV resonance in diphotons,
we also consider the potential to probe its parity-preserving couplings to
electrons, quarks and gluons with this method. In particular, combining the
diphoton signal with indirect constraints from $g_e-2$ and isotope shifts in
Ytterbium allows to probe the resonance coupling to electrons with
unprecedented precision.


title:
Algebraic equation and quadratic differential related to generalized
  Bessel polynomials with varying parameters

abstract:
  The limiting set of zeros of generalized Bessel polynomials with varying
parameters depending on the degree n cluster in a curve on the complex plane,
which is a finite critical trajectory of a quadratic differential in the form
{\lambda}^2(((z-a)(z-b))/(z^4))dz^2. The motivation of this paper is the
description of the critical graphs of these quadratic differentials. In
particular, we give a necessary and sufficient condition on the existence of
short trajectories.


title: Tridiagonalization and the Heun equation

abstract:
  It is shown that the tridiagonalization of the hypergeometric operator $L$
yields the generic Heun operator $M$. The algebra generated by the operators
$L,M$ and $Z=[L,M]$ is quadratic and a one-parameter generalization of the
Racah algebra. The new Racah-Heun orthogonal polynomials are introduced as
overlap coefficients between the eigenfunctions of the operators $L$ and $M$.
An interpretation in terms of the Racah problem for $su(1,1)$ algebras and
separation of variables in a superintegrable system are discussed.


title:
Wearable Embroidered Muscle Activity Sensing Device for the Human Upper
  Leg

abstract:
  Within the last decade, running has become one of the most popular physical
activities in the world. Although the benefits of running are numerous, there
is a risk of Running Related Injuries (RRI) of the lower extremities.
Electromyography (EMG) techniques have previously been used to study causes of
RRIs, but the complexity of this technology limits its use to a laboratory
setting. As running is primarily an outdoors activity, this lack of technology
acts as a barrier to the study of RRIs in natural environments. This study
presents a minimally invasive wearable muscle sensing device consisting of
jogging leggings with embroidered surface EMG (sEMG) electrodes capable of
recording muscle activity data of the quadriceps group. To test the use of the
device, a proof of concept study consisting of $N=2$ runners performing a set
of $5km$ running trials is presented in which the effect of running surfaces on
muscle fatigue, a potential cause of RRIs, is evaluated. Results show that
muscle fatigue can be analysed from the sEMG data obtained through the wearable
device, and that running on soft surfaces (such as sand) may increase the
likelihood of suffering from RRIs.


title: Quantifying Residual Finiteness of Linear Groups

abstract:
  Normal residual finiteness growth measures how well a finitely generated
group is approximated by its finite quotients. We show that any linear group
$\Gamma \leq \mathrm{GL}_d(K)$ has normal residual finiteness growth
asymptotically bounded above by $(n\log n)^{d^2-1}$; notably this bound depends
only on the degree of linearity of $\Gamma$. We also give precise asymptotics
in the case that $\Gamma$ is a subgroup of a higher rank Chevalley group $G$
and compute the non-normal residual finiteness growth in these cases. In
particular, finite index subgroups of $G(\mathbb{Z})$ and $G(\mathbb{F}_p[t])$
have normal residual finiteness growth $n^{\dim(G)}.$


title:
Formation of Massive Population III Galaxies through Photoionization
  Feedback: A Possible Explanation for CR7

abstract:
  We explore the formation of massive high-redshift Population III (Pop III)
galaxies through photoionization feedback. We consider dark matter halos formed
from progenitors that have undergone no star formation as a result of early
reionization and photoevaporation caused by a nearby galaxy. Once such a halo
reaches $\approx 10^9~M_\odot$, corresponding to the Jeans mass of the
photoheated intergalactic medium (IGM) at $z\approx 7$, pristine gas is able to
collapse into the halo, potentially producing a massive Pop III starburst. We
suggest that this scenario may explain the recent observation of strong He II
1640~\AA~line emission in CR7, which is consistent with $\sim 10^7~M_\odot$ of
young Pop III stars. Such a large mass of Pop III stars is unlikely without the
photoionization feedback scenario, because star formation is expected to inject
metals into halos above the atomic cooling threshold ($\sim 10^8~M_\odot$ at $z
\approx 7$). We use merger trees to analytically estimate the abundance of
observable Pop III galaxies formed through this channel, and find a number
density of $\approx 10^{-7}~{\rm Mpc^{-3}}$ at $z=6.6$ (the redshift of CR7).
This is approximately a factor of ten lower than the density of Ly$\alpha$
emitters as bright as CR7.


title:
Fast Memory-efficient Anomaly Detection in Streaming Heterogeneous
  Graphs

abstract:
  Given a stream of heterogeneous graphs containing different types of nodes
and edges, how can we spot anomalous ones in real-time while consuming bounded
memory? This problem is motivated by and generalizes from its application in
security to host-level advanced persistent threat (APT) detection. We propose
StreamSpot, a clustering based anomaly detection approach that addresses
challenges in two key fronts: (1) heterogeneity, and (2) streaming nature. We
introduce a new similarity function for heterogeneous graphs that compares two
graphs based on their relative frequency of local substructures, represented as
short strings. This function lends itself to a vector representation of a
graph, which is (a) fast to compute, and (b) amenable to a sketched version
with bounded size that preserves similarity. StreamSpot exhibits desirable
properties that a streaming application requires---it is (i) fully-streaming;
processing the stream one edge at a time as it arrives, (ii) memory-efficient;
requiring constant space for the sketches and the clustering, (iii) fast;
taking constant time to update the graph sketches and the cluster summaries
that can process over 100K edges per second, and (iv) online; scoring and
flagging anomalies in real time. Experiments on datasets containing simulated
system-call flow graphs from normal browser activity and various attack
scenarios (ground truth) show that our proposed StreamSpot is high-performance;
achieving above 95% detection accuracy with small delay, as well as competitive
time and memory usage.


title: High-Quality, Low-Delay Music Coding in the Opus Codec

abstract:
  The IETF recently standardized the Opus codec as RFC6716. Opus targets a wide
range of real-time Internet applications by combining a linear prediction coder
with a transform coder. We describe the transform coder, with particular
attention to the psychoacoustic knowledge built into the format. The result
out-performs existing audio codecs that do not operate under real-time
constraints.


title: Revisiting the canonicity of canonical triangulations

abstract:
  Stable derivators provide an enhancement of triangulated categories as is
indicated by the existence of canonical triangulations. In this paper we show
that exact morphisms of stable derivators induce exact functors of canonical
triangulations, and similarly for arbitrary natural transformations. This
2-categorical refinement also provides a uniqueness statement concerning
canonical triangulations.
  These results rely on a more careful study of morphisms of derivators and
this study is of independent interest. We analyze the interaction of morphisms
of derivators with limits, colimits, and Kan extensions, including a discussion
of invariance and closure properties of the class of Kan extensions preserved
by a fixed morphism.


title: Black-box optimization with a politician

abstract:
  We propose a new framework for black-box convex optimization which is
well-suited for situations where gradient computations are expensive. We derive
a new method for this framework which leverages several concepts from convex
optimization, from standard first-order methods (e.g. gradient descent or
quasi-Newton methods) to analytical centers (i.e. minimizers of self-concordant
barriers). We demonstrate empirically that our new technique compares favorably
with state of the art algorithms (such as BFGS).


title: Option Pricing in Markets with Unknown Stochastic Dynamics

abstract:
  We consider arbitrage free valuation of European options in Black-Scholes and
Merton markets, where the general structure of the market is known, however the
specific parameters are not known. In order to reflect this subjective
uncertainty of a market participant, we follow a Bayesian approach to option
pricing. Here we use historic discrete or continuous observations of the market
to set up posterior distributions for the future market. Given a subjective
physical measure for the market dynamics, we derive the existence of arbitrage
free pricing rules by constructing subjective option pricing measures. The
non-uniqueness of such measures can be proven using the freedom of choice of
prior distributions. The subjective market measure thus turns out to model an
incomplete market. In addition, for the Black-Scholes market we prove that in
the high frequency limit (or the long time limit) of observations, Bayesian
option prices converge to the standard BS-Option price with the true
volatility. In contrast to this, in the Merton market with normally distributed
jumps Bayesian prices do not converge to standard Merton prices with the true
parameters, as only a finite number of jump events can be observed in finite
time. However, we prove that this convergence holds true in the limit of long
observation times.


title: Reconsideration of De Donder-Weyl theory by covariant analytic mechanics

abstract:
  We show that the covariant analytic mechanics (CAM) is closely related to the
De Donder-Weyl (DW) theory. To treat space and time on an equal footing, the DW
theory introduces $D$ conjugate fields ($D$ is the dimension of space-time) for
each field and the CAM regards the differential forms as the basic variables.
The generalization of the canonical equations is called the DW equations.
Although one of the DW equations is not correct for the gauge field and the
gravitational field, we show the way to improve it. By rewriting the canonical
equations of the CAM, which are manifestly general coordinate covariant and
gauge covariant, using the components of the tensors, we show that these are
equivalent to the improved DW equations. Additionally, we investigate the Dirac
field. We present a modified Hamilton formalism which regards only the Dirac
fields as the basic variables and show that it provides the Dirac equations
correctly.


title: Memory properties of transformations of linear processes

abstract:
  In this paper, we study the memory properties of transformations of linear
processes. Dittmann and Granger (2002) studied the polynomial transformations
of Gaussian FARIMA(0,d,0) processes by applying the orthonormality of the
Hermite polynomials under the measure for the standard normal distribution.
Nevertheless, the orthogonality does not hold for transformations of
non-Gaussian linear processes. Instead, we use the decomposition developed by
Ho and Hsing (1996, 1997) to study the memory properties of nonlinear
transformations of linear processes, which include the FARIMA(p,d,q) processes,
and obtain consistent results as in the Gaussian case. In particular, for
stationary processes, the transformations of short-memory time series still
have short-memory and the transformation of long-memory time series may have
different weaker memory parameters which depend on the power rank of the
transformation. On the other hand, the memory properties of transformations of
non-stationary time series may not depend on the power ranks of the
transformations. This study has application in econometrics and financial data
analysis when the time series observations have non-Gaussian heavy tails. As an
example, the memory properties of call option processes at different strike
prices are discussed in details.


title: General distribution of consumers in pure Hotelling games

abstract:
  A pure Hotelling game is a competition between a finite number of players who
select simultaneously a location in order to attract as many consumers as
possible. In this paper, we study the case of a general distribution of
consumers on a network generated by a metric graph. Because players do not
compete on price, the continuum of consumers shop at the closest player's
location. Under regularity hypothesis on the distribution we prove the
existence of an epsilon-equilibrium in pure strategies and we construct it,
provided that the number of players is larger than a lower bound.


title: Experimental measurement of the collectibility of two-qubit states

abstract:
  We present a proof-of-principle experiment demonstrating measurement of the
collectibility, a nonlinear entanglement witness proposed by Rudnicki et al.
[Phys. Rev. Lett. 107, 150502 (2011)]. This entanglement witness works for both
mixed and pure two-qubit states. In the later case it can be used to measure
entanglement in terms of the negativity. We measured the collectibility for
three distinct classes of photonic polarization-encoded two-qubit states, i.e.,
maximally entangled, separable and maximally mixed states. We demonstrate that
the measurement procedure is feasible and robust against typical experimental
shortcomings such as imperfect two-photon indistinguishability.


title: Complex Networks of Words in Fables

abstract:
  In this chapter we give an overview of the application of complex network
theory to quantify some properties of language. Our study is based on two
fables in Ukrainian, Mykyta the Fox and Abu-Kasym's slippers. It consists of
two parts: the analysis of frequency-rank distributions of words and the
application of complex-network theory. The first part shows that the text sizes
are sufficiently large to observe statistical properties. This supports their
selection for the analysis of typical properties of the language networks in
the second part of the chapter. In describing language as a complex network,
while words are usually associated with nodes, there is more variability in the
choice of links and different representations result in different networks.
Here, we examine a number of such representations of the language network and
perform a comparative analysis of their characteristics. Our results suggest
that, irrespective of link representation, the Ukrainian language network used
in the selected fables is a strongly correlated, scale-free, small world. We
discuss how such empirical approaches may help form a useful basis for a
theoretical description of language evolution and how they may be used in
analyses of other textual narratives.


title: Information Diffusion of Topic Propagation in Social Media

abstract:
  Real-world social and/or operational networks consist of agents with
associated states, whose connectivity forms complex topologies. This complexity
is further compounded by interconnected information layers, consisting, for
instance, documents/resources of the agents which mutually share topical
similarities. Our goal in this work is to predict the specific states of the
agents, as their observed resources evolve in time and get updated. The
information diffusion among the agents and the publications themselves
effectively result in a dynamic process which we capture by an interconnected
system of networks (i.e. layered). More specifically, we use a notion of a
supra-Laplacian matrix to address such a generalized diffusion of an
interconnected network starting with the classical "graph Laplacian". The
auxiliary and external input update is modeled by a multidimensional Brownian
process, yielding two contributions to the variations in the states of the
agents: one that is due to the intrinsic interactions in the network system,
and the other due to the external inputs or innovations. A variation on this
theme, a priori knowledge of a fraction of the agents' states is shown to lead
to a Kalman predictor problem. This helps us refine the predicted states
exploiting the error in estimating the states of agents. Three real-world
datasets are used to evaluate and validate the information diffusion process in
this novel layered network approach. Our results demonstrate a lower prediction
error when using the interconnected network rather than the single connectivity
layer between the agents. The prediction error is further improved by using the
estimated diffusion connection and by applying the Kalman approach with partial
observations.


title:
Conformal Mapping via a Density Correspondence for the Double-Layer
  Potential

abstract:
  We derive a representation formula for harmonic polynomials and Laurent
polynomials in terms of densities of the double-layer potential on bounded
piecewise smooth and simply connected domains. From this result, we obtain a
method for the numerical computation of conformal maps that applies to both
exterior and interior regions. We present analysis and numerical experiments
supporting the accuracy and broad applicability of the method.


title: Global simulations of galactic winds including cosmic ray streaming

abstract:
  Galactic outflows play an important role in galactic evolution. Despite their
importance, a detailed understanding of the physical mechanisms responsible for
the driving of these winds is lacking. In an effort to gain more insight into
the nature of these flows, we perform global three-dimensional
magneto-hydrodynamical simulations of an isolated Milky Way-size starburst
galaxy. We focus on the dynamical role of cosmic rays injected by supernovae,
and specifically on the impact of the streaming and anisotropic diffusion of
cosmic rays along the magnetic fields. We find that these microphysical effects
can have a significant effect on the wind launching and mass loading factors
depending on the details of the plasma physics. Due to the cosmic ray streaming
instability, cosmic rays propagating in the interstellar medium scatter on
self-excited Alfven waves and couple to the gas. When the wave growth due to
the streaming instability is inhibited by some damping process, such as the
turbulent damping, the cosmic ray coupling to the gas is weaker and their
effective propagation speed faster than the Alfven speed. Alternatively, cosmic
rays could scatter from "extrinsic turbulence" that is driven by another
mechanism. We demonstrate that the presence of moderately super-Alfvenic cosmic
ray streaming enhances the efficiency of galactic wind driving. Cosmic rays
stream away from denser regions near the galactic disk along partially ordered
magnetic fields and, in the process, accelerate more tenuous gas away from the
galaxy. For cosmic ray acceleration efficiencies broadly consistent with the
observational constraints, cosmic rays reduce the galactic star formation rates
and significantly aid in launching galactic winds.


title:
Fans and their applications in General Topology, Functional Analysis and
  Topological Algebra

abstract:
  A family of closed subsets of a topological space $X$ is called a (strict)
$Cld$-fan in $X$ if this family is (strictly) compact-finite but not locally
finite in $X$. Applications of (strict) $Cld$-fans are based on a simple
observation that $k$-spaces contain no $Cld$-fan and Ascoli spaces contain no
strict $Cld$-fan. In this paper we develop the machinery of (strict) fans and
apply it to detecting the $k$-space and Ascoli properties in spaces that
naturally appear in General Topology, Functional Analysis, and Topological
Algebra. In particular, we detect (generalized) metric spaces $X$ whose
functor-spaces, functions spaces, free (para)topological (abelian) groups, free
(locally convex) linear topological spaces, free (Lawson) topological
semilattices, and free (para)topological (Clifford, Abelian) inverse semigroups
are $k$-spaces or Ascoli spaces.


title:
Geometric Multigrid for Darcy and Brinkman models of flows in highly
  heterogeneous porous media: A numerical study

abstract:
  We apply geometric multigrid methods for the finite element approximation of
flow problems governed by Darcy and Brinkman systems used in modeling highly
heterogeneous porous media. The method is based on divergence-conforming
discontinuous Galerkin methods and overlapping, patch based domain
decomposition smoothers. We show in benchmark experiments that the method is
robust with respect to mesh size and contrast of permeability for highly
heterogeneous media.


title: Reheating the Universe at Criticality

abstract:
  We present the general discussion on the inflection point inflation with
small or large inflaton fields and show the effects of reheating dynamics on
the inflationary predictions. In order to compare the model predictions with
precisely measured CMB anisotropies and constrain the inflation models, the
knowledge of the reheating dynamics is required. Inflection point inflation
extended to the trans-Planckian regime can accommodate a sizable
tensor-to-scalar ratio at the detectable level in the future CMB experiments.


title: Dual-Context Calculi for Modal Logic

abstract:
  We present natural deduction systems and associated modal lambda calculi for
the necessity fragments of the normal modal logics K, T, K4, GL and S4. These
systems are in the dual-context style: they feature two distinct zones of
assumptions, one of which can be thought as modal, and the other as
intuitionistic. We show that these calculi have their roots in in sequent
calculi. We then investigate their metatheory, equip them with a confluent and
strongly normalizing notion of reduction, and show that they coincide with the
usual Hilbert systems up to provability. Finally, we investigate a categorical
semantics which interprets the modality as a product-preserving functor.


title: Version 1 of the Hubble Source Catalog

abstract:
  The Hubble Source Catalog is designed to help optimize science from the
Hubble Space Telescope by combining the tens of thousands of visit-based source
lists in the Hubble Legacy Archive into a single master catalog. Version 1 of
the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR
photometric data generated using SExtractor software to produce the individual
source lists. The catalog includes roughly 80 million detections of 30 million
objects involving 112 different detector/filter combinations, and about 160
thousand HST exposures. Source lists from Data Release 8 of the Hubble Legacy
Archive are matched using an algorithm developed by Budavari & Lubow (2012).
The mean photometric accuracy for the catalog as a whole is better than 0.10
mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g.,
bright isolated stars). The relative astrometric residuals are typically within
10 mas, with a value for the mode (i.e., most common value) of 2.3 mas. The
absolute astrometric accuracy is better than $\sim$0.1 arcsec for most sources,
but can be much larger for a fraction of fields that could not be matched to
the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the
database design with emphasis on those aspects that enable the users to fully
exploit the catalog while avoiding common misunderstandings and potential
pitfalls. We provide usage examples to illustrate some of the science
capabilities and data quality characteristics, and briefly discuss plans for
future improvements to the Hubble Source Catalog.


title:
Local-likelihood transformation kernel density estimation for positive
  random variables

abstract:
  The kernel estimator is known not to be adequate for estimating the density
of a positive random variable X. The main reason is the well-known boundary
bias problems that it suffers from, but also its poor behaviour in the long
right tail that such a density typically exhibits. A natural approach to this
problem is to first estimate the density of the logarithm of X, and obtaining
an estimate of the density of X using standard results on functions of random
variables (`back-transformation'). Although intuitive, the basic application of
this idea yields very poor results, as was documented earlier in the
literature. In this paper, the main reason for this underachievement is
identified, and an easy fix is suggested. It is demonstrated that combining the
transformation with local likelihood density estimation methods produces very
good estimators of R+-supported densities, not only close to the boundary, but
also in the right tail. The asymptotic properties of the proposed `local
likelihood transformation kernel density estimators' are derived for a generic
transformation, not only for the logarithm, which allows one to consider other
transformations as well. One of them, called the `probex' transformation, is
given more focus. Finally, the excellent behaviour of those estimators in
practice is evidenced through a comprehensive simulation study and the analysis
of several real data sets. A nice consequence of articulating the method around
local-likelihood estimation is that the resulting density estimates are
typically smooth and visually pleasant, without oversmoothing important
features of the underlying density.


title:
Dismantlable classifying space for the family of parabolic subgroups of
  a relatively hyperbolic group

abstract:
  Let $G$ be a group hyperbolic relative to a finite collection of subgroups
$\mathcal P$. Let $\mathcal F$ be the family of subgroups consisting of all the
conjugates of subgroups in $\mathcal P$, all their subgroups, and all finite
subgroups. Then there is a cocompact model for $E_{\mathcal F} G$. This result
was known in the torsion-free case. In the presence of torsion, a new approach
was necessary. Our method is to exploit the notion of dismantlability. A number
of sample applications are discussed.


title:
Kubo-Bastin approach for the spin Hall conductivity of decorated
  graphene

abstract:
  Theoretical predictions and recent experimental results suggest one can
engineer spin Hall effect in graphene by enhancing the spin-orbit coupling in
the vicinity of an impurity. We use a Chebyshev expansion of the Kubo-Bastin
formula to compute the spin conductivity tensor for a tight-binding model of
graphene with randomly distributed impurities absorbed on top of carbon atoms.
We model the impurity-induced spin-orbit coupling with a graphene-only
Hamiltonian that takes into account three different
contributions~\cite{Gmitra2013} and show how the spin Hall and longitudinal
conductivities depend on the strength of each spin-orbit coupling and the
concentration of impurities. Additionally, we calculate the real-space
projection of the density of states in the vicinity of the Dirac point for
single and multiple impurities and correlate these results with the
conductivity calculations.


title: The Most Luminous Supernovae

abstract:
  Recent observations have revealed an amazing diversity of extremely luminous
supernovae, seemingly increasing in radiant energy without bound. We consider
here the physical limits of what existing models can provide for the peak
luminosity and total radiated energy for non-relativistic, isotropic stellar
explosions. The brightest possible supernova is a Type I explosion powered by a
sub-millisecond magnetar. Such models can reach a peak luminosity of $\rm
2\times10^{46}\ erg\ s^{-1}$ and radiate a total energy of $\rm 4
\times10^{52}\ erg$. Other less luminous models are also explored, including
prompt hyper-energetic explosions in red supergiants, pulsational-pair
instability supernovae, and pair-instability supernovae. Approximate analytic
expressions and limits are given for each case. Excluding magnetars, the peak
luminosity is near $\rm 1\times10^{44}\ erg\ s^{-1}$ for the brightest models.
The corresponding limits on total radiated power are $\rm3 \times 10^{51}\ erg$
(Type I) and $\rm1 \times 10^{51}\ erg$ (Type II). A magnetar-based model for
the recent transient event, ASASSN-15lh is presented that strains, but does not
exceed the limits of what the model can provide.


title: A Fermi golden rule for quantum graphs

abstract:
  We present a Fermi golden rule giving rates of decay of states obtained by
perturbing embedded eigenvalues of a quantum graph. To illustrate the procedure
in a notationally simpler setting we also present a Fermi Golden Rule for
boundary value problems on surfaces with constant curvature cusps. We also
provide a resonance existence result which is uniform on compact sets of
energies and metric graphs. The results are illustrated by numerical
experiments.


title: Experimental and numerical study of error fields in the CNT stellarator

abstract:
  Sources of error fields were indirectly inferred in a stellarator by
reconciling computed and numerical flux surfaces. Sources considered so far
include the displacements and tilts (but not the deformations, yet) of the four
circular coils featured in the simple CNT stellarator. The flux surfaces were
measured by means of an electron beam and phosphor rod, and were computed by
means of a Biot-Savart field-line tracing code. If the ideal coil locations and
orientations are used in the computation, agreement with measurements is poor.
Discrepancies are ascribed to errors in the positioning and orientation of the
in-vessel interlocked coils. To that end, an iterative numerical method was
developed. A Newton-Raphson algorithm searches for the coils' displacements and
tilts that minimize the discrepancy between the measured and computed flux
surfaces. This method was verified by misplacing and tilting the coils in a
numerical model of CNT, calculating the flux surfaces that they generated, and
testing the algorithm's ability to deduce the coils' displacements and tilts.
Subsequently, the numerical method was applied to the experimental data,
arriving at a set of coil displacements whose resulting field errors exhibited
significantly improved quantitative and qualitative agreement with experimental
results.


title: Deep Feature-based Face Detection on Mobile Devices

abstract:
  We propose a deep feature-based face detector for mobile devices to detect
user's face acquired by the front facing camera. The proposed method is able to
detect faces in images containing extreme pose and illumination variations as
well as partial faces. The main challenge in developing deep feature-based
algorithms for mobile devices is the constrained nature of the mobile platform
and the non-availability of CUDA enabled GPUs on such devices. Our
implementation takes into account the special nature of the images captured by
the front-facing camera of mobile devices and exploits the GPUs present in
mobile devices without CUDA-based frameorks, to meet these challenges.


title:
Development and Evaluation of a Quantum Interactive Learning Tutorial on
  Larmor Precession Of Spin

abstract:
  We conducted research on student difficulties and developed and evaluated a
quantum interactive learning tutorial (QuILT) on Larmor precession of spin to
help students learn about time-dependence of expectation values in quantum
mechanics. The QuILT builds on students' prior knowledge and strives to help
them develop a good knowledge structure of relevant concepts. It adapts
visualization tools to help students develop intuition about these topics and
focuses on helping them integrate qualitative and quantitative understanding.
Here, we summarize the development and preliminary evaluation.


title: Entanglement assisted state discrimination and entanglement preservation

abstract:
  In this paper, the following scenario is considered: there are two qubits
possessed by two parties at different locations. Qubits have been prepared in
one of a maximum of four, mutually-orthogonal, entangled states and the parties
wish to distinguish between the states by using local operations and classical
communication. Although in general it is not possible to distinguish between
four arbitrary states, the parties can spend some pre-shared entanglement to
achieve perfect discrimination between four qubit states and can also preserve
the entanglement of the states after discrimination. This is shown by employing
the theory of majorization and the connections between entanglement
transformations and state discrimination protocols.


title:
Developing a Magnetism Conceptual Survey and Assessing Gender
  Differences in Student Understanding of Magnetism

abstract:
  We discuss the development of a research-based conceptual multiple-choice
survey related to magnetism. We also discuss the use of the survey to
investigate gender differences in students' difficulties with concepts related
to magnetism. We find that while there was no gender difference on the
pre-test, female students performed significantly worse than male students when
the survey was given as a post-test in traditionally taught calculus-based
introductory physics courses (similar results in both the regular and honors
versions of the course). In the algebra-based courses, the performance of the
female students and the male students has no statistical difference in the
pre-test or the post-test.


title: Students' Difficulties with Equations involving Circuit Elements

abstract:
  We discuss an investigation exploring students' difficulties with equations
involving resistance, capacitance and inductance. We find that introductory
physics students have great difficulty understanding, e.g., how the resistance
of an ohmic resistor can be written in terms of the potential difference across
it and the current through it, but it does not change when the potential
difference across the resistor is varied. Similar confusions arose in problems
relating to capacitors and inductors. We discuss these difficulties with
equations in the context of introductory physics students' performance on
questions about circuit elements both in the free-response and multiple-choice
formats.


title: A Stochastic Performance Model for Pipelined Krylov Methods

abstract:
  Pipelined Krylov methods seek to ameliorate the latency due to inner products
necessary for projection by overlapping it with the computation associated with
sparse matrix-vector multiplication. We clarify a folk theorem that this can
only result in a speedup of $2\times$ over the naive implementation. Examining
many repeated runs, we show that stochastic noise also contributes to the
latency, and we model this using an analytical probability distribution. Our
analysis shows that speedups greater than $2\times$ are possible with these
algorithms.


title:
Bi-directional LSTM Recurrent Neural Network for Chinese Word
  Segmentation

abstract:
  Recurrent neural network(RNN) has been broadly applied to natural language
processing(NLP) problems. This kind of neural network is designed for modeling
sequential data and has been testified to be quite efficient in sequential
tagging tasks. In this paper, we propose to use bi-directional RNN with long
short-term memory(LSTM) units for Chinese word segmentation, which is a crucial
preprocess task for modeling Chinese sentences and articles. Classical methods
focus on designing and combining hand-craft features from context, whereas
bi-directional LSTM network(BLSTM) does not need any prior knowledge or
pre-designing, and it is expert in keeping the contextual information in both
directions. Experiment result shows that our approach gets state-of-the-art
performance in word segmentation on both traditional Chinese datasets and
simplified Chinese datasets.


title: POMDP-lite for Robust Robot Planning under Uncertainty

abstract:
  The partially observable Markov decision process (POMDP) provides a
principled general model for planning under uncertainty. However, solving a
general POMDP is computationally intractable in the worst case. This paper
introduces POMDP-lite, a subclass of POMDPs in which the hidden state variables
are constant or only change deterministically. We show that a POMDP-lite is
equivalent to a set of fully observable Markov decision processes indexed by a
hidden parameter and is useful for modeling a variety of interesting robotic
tasks. We develop a simple model-based Bayesian reinforcement learning
algorithm to solve POMDP-lite models. The algorithm performs well on
large-scale POMDP-lite models with up to $10^{20}$ states and outperforms the
state-of-the-art general-purpose POMDP algorithms. We further show that the
algorithm is near-Bayesian-optimal under suitable conditions.


title: VPSolver 3: Multiple-choice Vector Packing Solver

abstract:
  VPSolver is a vector packing solver based on an arc-flow formulation with
graph compression. In this paper, we present the algorithm introduced in
VPSolver 3.0.0 for building compressed arc-flow models for the multiple-choice
vector packing problem.


title: Fast DGT Based Receivers for GFDM in Broadband Channels

abstract:
  Generalized frequency division multiplexing (GFDM) is a recent multicarrier
5G waveform candidate with flexibility of pulse shaping filters. However, the
flexibility of choosing a pulse shaping filter may result in inter carrier
interference (ICI) and inter symbol interference (ISI), which becomes more
severe in a broadband channel. In order to eliminate the ISI and ICI, based on
discrete Gabor transform (DGT), in this paper, a transmit GFDM signal is first
treated as an inverse DGT (IDGT), and then a frequency-domain DGT is formulated
to recover (as a receiver) the GFDM signal. Furthermore, to reduce the
complexity, a suboptimal frequency-domain DGT called local DGT (LDGT) is
developed. Some analyses are also given for the proposed DGT based receivers.


title: Kinsey Reporter: Citizen Science for Sex Research

abstract:
  Kinsey Reporter is a global mobile app to share, explore, and visualize
anonymous data about sex. Reports are submitted via smartphone, then visualized
on a website or downloaded for offline analysis. In this paper we present the
major features of the Kinsey Reporter citizen science platform designed to
preserve the anonymity of its contributors, and preliminary data analyses that
suggest questions for future research.


title:
M Dwarf Flare Continuum Variations on One-Second Timescales: Calibrating
  and Modeling of ULTRACAM Flare Color Indices

abstract:
  We present a large dataset of high cadence dMe flare light curves obtained
with custom continuum filters on the triple-beam, high-speed camera system
ULTRACAM. The measurements provide constraints for models of the NUV and
optical continuum spectral evolution on timescales of ~1 second. We provide a
robust interpretation of the flare emission in the ULTRACAM filters using
simultaneously-obtained low-resolution spectra during two moderate-sized flares
in the dM4.5e star YZ CMi. By avoiding the spectral complexity within the
broadband Johnson filters, the ULTRACAM filters are shown to characterize
bona-fide continuum emission in the NUV, blue, and red wavelength regimes. The
NUV/blue flux ratio in flares is equivalent to a Balmer jump ratio, and the
blue/red flux ratio provides an estimate for the color temperature of the
optical continuum emission. We present a new "color-color" relationship for
these continuum flux ratios at the peaks of the flares. Using the RADYN and RH
codes, we interpret the ULTRACAM filter emission using the dominant emission
processes from a radiative-hydrodynamic flare model with a high nonthermal
electron beam flux, which explains a hot, T~10,000 K, color temperature at
blue-to-red optical wavelengths and a small Balmer jump ratio as are observed
in moderate-sized and large flares alike. We also discuss the high
time-resolution, high signal-to-noise continuum color variations observed in YZ
CMi during a giant flare, which increased the NUV flux from this star by over a
factor of 100.


title: Hydrodynamic drift ratchet scalability

abstract:
  The rectilinear "drift" of particles in a hydrodynamic drift ratchet arises
from a combination of diffusive motion and particle-wall hydrodynamic
interactions, and is therefore dependent on particle diffusivity, particle
size, the amplitude and frequency of fluid oscillation and pore geometry. Using
numerical simulations, we demonstrate that the drift velocity relative to the
pore size is constant across different sized drift ratchet pores, if all the
relevant non-dimensional groups (Peclet number, Strouhal number and ratio of
particle to pore size) remain constant. These results clearly indicate for the
first time the scaling parameters under which the drift ratchet achieves
dynamic similarity, and so facilitates design, fabrication and testing of drift
ratchets for experiments and eventually as commercial micro/nano fluidic
separation devices.


title: Universal Systems of Oblivious Mobile Robots

abstract:
  An oblivious mobile robot is a stateless computational entity located in a
spatial universe, capable of moving in that universe. When activated, the robot
observes the universe and the location of the other robots, chooses a
destination, and moves there. The computation of the destination is made by
executing an algorithm, the same for all robots, whose sole input is the
current observation. No memory of all these actions is retained after the move.
When the universe is a graph, distributed computations by oblivious mobile
robots have been intensively studied focusing on the conditions for feasibility
of basic problems (e.g., gathering, exploration) in specific classes of graphs
under different schedulers. In this paper, we embark on a different, more
general, type of investigation.
  With their movements from vertices to neighboring vertices, the robots make
the system transition from one configuration to another. Viewing this
transition as the computation of an abstract function, we ask which functions
are computed by which systems. Our main interest is on identifying sets of
systems that are "universal", in the sense that they can collectively compute
all finite functions. We are able to identify several such classes of fully
synchronous systems. In particular, among other results, we prove the
universality of the set of all graphs with at least one robot, of any set of
graphs with at least two robots whose quotient graphs contain arbitrarily long
paths, and of any set of graphs with at least three robots and arbitrarily
large finite girths.
  We then focus on the minimum size that a network must have for the robots to
be able to compute all functions on a given finite set. We are able to
approximate the minimum size of such a network up to a factor that tends to 2
as $n$ goes to infinity.


title:
Construction of Orthonormal Quasi-Shearlets based on quincunx dilation
  subsampling

abstract:
  We consider the construction of orthonormal directional wavelet bases in the
multi-resolution analysis (MRA) framework with quincunx dilation downsampling.
We show that the Parseval frame property in MRA is equivalent to the identity
summation and shift cancellation conditions on M functions, which essentially
characterize the scaling (father) function and all directional (mother)
wavelets. Based on these two conditions, we further derive sufficient
conditions for orthonormal bases and build a family of quasishearlet
orthonormal bases, that has the same frequency support as that of the least
redundant shearlet system. In addition, we study the limitation of our proposed
bases design due to the shift cancellation conditions.


title:
Damping and power spectra of quasi-periodic intensity disturbances above
  a solar polar coronal hole

abstract:
  We study intensity disturbances above a solar polar coronal hole seen in the
AIA 171 \AA\ and 193 \AA\ passbands, aiming to provide more insights into their
physical nature. The damping and power spectra of the intensity disturbances
with frequencies from 0.07 mHz to 10.5 mHz are investigated. The damping of the
intensity disturbances tends to be stronger at lower frequencies, and their
damping behavior below 980" (for comparison, the limb is at 945") is different
from what happens above. No significant difference is found between the damping
of the intensity disturbances in the AIA 171 \AA\ and that in the AIA 193 \AA.
The indices of the power spectra of the intensity disturbances are found to be
slightly smaller in the AIA 171 \AA\ than in the AIA 193 \AA, but the
difference is within one sigma deviation. An additional enhanced component is
present in the power spectra in a period range of 8--40 minutes at lower
heights. While the power spectra of spicule is highly correlated with its
associated intensity disturbance, it suggests that the power spectra of the
intensity disturbances might be a mixture of spicules and wave activities. We
suggest that each intensity disturbance in the polar coronal hole is possibly a
series of independent slow magnetoacoustic waves triggered by spicular
activities.


title:
Weighted inequalities for quasilinear integral operators on the semiaxis
  and application to the Lorentz spaces

abstract:
  Weighted $L^p-L^r$ inequalities with arbitrary measurable non-negative
weights for positive quasilinear integral operators with Oinarov's kernel on
the semiaxis are characterized. Application to the boundedness of maximal
operator in the Lorentz $\Gamma-$spaces is given.


title: First fundamental theorems of invariant theory for quantum supergroups

abstract:
  Let $U_q(\mathfrak{g})$ be the quantum supergroup of $\mathfrak{gl}_{m|n}$ or
the modified quantum supergroup of $osp_{m|2n}$ over the field of rational
functions in $q$, and let $V_q$ be the natural module for $U_q(\mathfrak{g})$.
There exists a unique tensor functor, associated with $V_q$, from the category
of ribbon graphs to the category of finite dimensional representations of
$U_q(\mathfrak{g}$, which preserves ribbon category structures. We show that
this functor is full in the cases $\mathfrak{g}=\mathfrak{gl}_{m|n}$ or
$osp_{2\ell+1|2n}$. For $\mathfrak{g}=osp_{2\ell|2n}$, we show that the space
$Hom_{U_q(\mathfrak{g}}(V_q^{\otimes r}, V_q^{\otimes s})$ is spanned by images
of ribbon graphs if $r+s< 2\ell(2n+1)$. The proofs involve an equivalence of
module categories for two versions of the quantisation of $U(\mathfrak{g})$.


title: Fast, Robust, Continuous Monocular Egomotion Computation

abstract:
  We propose robust methods for estimating camera egomotion in noisy,
real-world monocular image sequences in the general case of unknown observer
rotation and translation with two views and a small baseline. This is a
difficult problem because of the nonconvex cost function of the perspective
camera motion equation and because of non-Gaussian noise arising from noisy
optical flow estimates and scene non-rigidity. To address this problem, we
introduce the expected residual likelihood method (ERL), which estimates
confidence weights for noisy optical flow data using likelihood distributions
of the residuals of the flow field under a range of counterfactual model
parameters. We show that ERL is effective at identifying outliers and
recovering appropriate confidence weights in many settings. We compare ERL to a
novel formulation of the perspective camera motion equation using a lifted
kernel, a recently proposed optimization framework for joint parameter and
confidence weight estimation with good empirical properties. We incorporate
these strategies into a motion estimation pipeline that avoids falling into
local minima. We find that ERL outperforms the lifted kernel method and
baseline monocular egomotion estimation strategies on the challenging KITTI
dataset, while adding almost no runtime cost over baseline egomotion methods.


title: An analytic derivation of the variance for the Abelian distribution

abstract:
  The Abelian distribution has been studied recently in models for neural
avalanches. This paper uncovers new properties about the moments of the
distribution, ways in which these properties can be useful are indicated.


title:
Long Range Azimuthal Correlations of Multiple Gluons in Gluon Saturation
  Limit

abstract:
  We calculate the inclusive gluon correlation function for arbitrary number of
gluons with full rapidity and transverse momentum dependence for the initial
glasma state of the p-p, p-A and A-A collisions. The formula we derive via
superdiagrams generates cumulants for any number of gluons. Higher order
cumulants contain information on correlations between multiple gluons, and they
are necessary for calculations of higher dimensional ridges as well as flow
coefficients from multi-particle correlations.


title: Unsupervised Domain Adaptation Using Approximate Label Matching

abstract:
  Domain adaptation addresses the problem created when training data is
generated by a so-called source distribution, but test data is generated by a
significantly different target distribution. In this work, we present
approximate label matching (ALM), a new unsupervised domain adaptation
technique that creates and leverages a rough labeling on the test samples, then
uses these noisy labels to learn a transformation that aligns the source and
target samples. We show that the transformation estimated by ALM has favorable
properties compared to transformations estimated by other methods, which do not
use any kind of target labeling. Our model is regularized by requiring that a
classifier trained to discriminate source from transformed target samples
cannot distinguish between the two. We experiment with ALM on simulated and
real data, and show that it outperforms techniques commonly used in the field.


title: Quantum statistical mechanics in arithmetic topology

abstract:
  This paper provides a construction of a quantum statistical mechanical system
associated to knots in the 3-sphere and cyclic branched coverings of the
3-sphere, which is an analog, in the sense of arithmetic topology, of the
Bost-Connes system, with knots replacing primes, and cyclic branched coverings
of the 3-sphere replacing abelian extensions of the field of rational numbers.
The operator algebraic properties of this system differ significantly from the
Bost-Connes case, due to the properties of the action of the semigroup of knots
on a direct limit of knot groups. The resulting algebra of observables is a
noncommutative Bernoulli crossed product. We describe the main properties of
the associated quantum statistical mechanical system and of the relevant
partition functions, which are obtained from simple knot invariants like genus
and crossing number.


title: Ring to Mountain Transition in Deposition Pattern of Drying

abstract:
  When a droplet containing a non-volatile component is dried on a substrate,
it leaves a ringlike deposit on the substrate. We propose a theory which
predicts the deposit distribution based on a model of fluid flow and contact
line motion of the droplet. It is shown that the deposition pattern changes
continuously from coffee-ring to volcano-like and to mountain-like depending on
the mobility of the contact line and the evaporation rate. Analytical
expression is given for the peak position of the distribution of deposit left
on the substrate.


title: Covariant approach of perturbations in Lovelock type brane gravity

abstract:
  We develop a covariant scheme to describe the dynamics of small perturbations
on Lovelock type extended objects propagating in a flat Minkowski spacetime.
The higher-dimensional analogue of the Jacobi equation in this theory becomes a
wave type equation for a scalar field $\Phi$. Whithin this framework, we
analyse the stability of membranes with a de Sitter geometry where we find that
the Jacobi equation specializes to a Klein-Gordon (KG) equation for $\Phi$
possessing a tachyonic mass. This shows that, to some extent, these type of
extended objects share the symmetries of the Dirac-Nambu-Goto (DNG) action
which is by no means coincidental because the DNG model is the simplest
included in this type of gravity.


title: Wave-Flow Interactions and Acoustic Streaming

abstract:
  The interaction of waves and flows is a challenging topic where a complete
resolution has been frustrated by the essential nonlinear features in the
hydrodynamic case. Even in the case of EM waves in flowing media, the results
are subtle. For a simple shear flow of constant n fluid, incident radiation is
shown to be reflected and refracted in an analogous manner to Snell's law.
However, the beam intensities differ and the system has an asymmetry in that an
internal reflection gap opens at steep incident angles nearly oriented with the
shear. For EM waves these effects are generally negligible in real systems but
they introduce the topic at a reduced level of complexity of the more
interesting acoustic case. Acoustic streaming is suggested, both from theory
and experimental data, to be associated with vorticity generation at the driver
itself. Bounds on the vorticity in bulk and nonlinear effects demonstrate that
the bulk sources, even with attenuation, cannot drive such a strong flow. A
review of the velocity scales in the problem suggest that a variation of the
Scholte wave at the driver-fluid interface with local cavitation on the
decompression phase creates a lateral flow of fluid that generates the stream
and imparts the vorticity from the driver plate. In the case of Darcy flow in
sintered media, an analysis of data suggests that acoustically enhanced flow
may be the result of surface effects that narrow channels that are cleared by
ultrasonic cavitation.


title:
On handlebody-knot pairs which realize exteriors of knotted surfaces in
  $S^3$

abstract:
  In this paper, we describe the relation between the study of closed connected
surfaces embedded in $S^3$ and the theory of handlebody-knots. By Fox's
theorem, a pair of handlebody-knots is associated to a closed connected surface
embedded in $S^3$ in the sense that their exterior components are pairwise
homeomorphic. We show that for every handlebody-knot pair associated to a genus
two "prime bi-knotted" surface, one is irreducible, and the other is reducible.
Furthermore, for given two genus two handlebody-knots $H_1$ and $H_2$
satisfying certain conditions, we will construct a "prime bi-knotted" surface
whose associated handlebody-knot pair coincides with $H_1$ and $H_2$.


title: Elementary construction of Lusztig's canonical basis

abstract:
  In this largely expository article we present an elementary construction of
Lusztig's canonical basis in type ADE. The method, which is essentially
Lusztig's original approach, is to use the braid group to reduce to rank two
calculations. Some of the wonderful properties of the canonical basis are
already visible; that it descends to a basis for every highest weight
integrable representation, and that it is a crystal basis.


title:
Fano Resonance Induced Anomalous Collective Hotspots in Metallic
  Nanoparticle Dimer Chains

abstract:
  Hotspots with strong near fields due to localized surface plasmons (LSPs) in
metallic nanostructures have various applications, such as surface enhanced
Raman scattering (SERS). The long range Coulomb coupling between LSPs in
periodic metallic nanostructures may lead to interesting collective effects. In
this paper, we investigate the combination effects of the local field
enhancement and collective plasmon resonances in one dimensional metallic
nanoparticle dimer chains. It is found that the strong near field in the gap
and the far field interactions among the metallic nanoparticles lead to
anomalous collective hotspots with dual enhancement of the electromagnetic
field. In particular, the interference between the incident field and the
induced internal field leads to Fano-type effect with Wood anomaly related
destructive interference and the strong resonance with an extremely narrow
width. Our systematic study shows that the correlation between the local
structure and the global structure has important impact on the collective
spots, which leads to an optimal orientation of the dimer (about 60{\deg} with
respect to the chain direction) for the largest gap field enhancement with the
incident field polarization parallel to the long axis of the dimer.


title: Homological stability for configuration spaces of orbifolds

abstract:
  We prove that homological stability holds for configuration spaces of
orbifolds. This builds on the work of Bailes' thesis where he proves that the
stabilisation maps are injective.


title:
Massive open star clusters using the VVV survey V. Young clusters with
  an OB stellar population

abstract:
  The ESO public survey VISTA Variables in the V\'ia L\'actea (VVV) has
contributed with deep multi-epoch photometry of the Galactic bulge and the
adjacent part of the disk over 526 square degrees. More than a hundred cluster
candidates have been reported thanks to this survey. We present the fifth
article in a series of papers focused on young and massive clusters discovered
in the VVV survey. In this paper, we present the physical characterization of
five clusters with a spectroscopically confirmed OB-type stellar population. To
characterize the clusters, we used near-infrared photometry ($J$, $H,$ and
$K_S$) from the VVV survey and near-infrared $K$-band spectroscopy from ISAAC
at VLT, following the methodology presented in the previous articles of the
series. All clusters in our sample are very young (ages between 1-20 Myr), and
their total mass are between $(1.07^{+0.40}_{-0.30})\cdot10^2$ $M_{\odot}$ and
$(4.17^{+4.15}_{-2.08})\cdot10^3$ $M_{\odot}$. We observed a relation between
the clusters total mass $M_{ecl}$ and the mass of their most massive stellar
member $m_{max}$, even for clusters with an age $<$ 10 Myr.


title:
The Spectroscopy and Form Factors of Nucleon Resonances from
  Superconformal Quantum Mechanics and Holographic QCD

abstract:
  The superconformal algebraic approach to hadronic physics is used to
construct a semiclassical effective theory for nucleons which incorporates
essential nonperturbative dynamical features, such as the emergence of a
confining scale and the Regge resonance spectrum. Relativistic bound-state
equations for nucleons follow from the extension of superconformal quantum
mechanics to the light front and its holographic embedding in a higher
dimensional gravity theory. Superconformal algebra has been used elsewhere to
describe the connections between the light mesons and baryons, but in the
present context it relates the fermion positive and negative chirality states
and uniquely determines the confinement potential of nucleons. The holographic
mapping of multi-quark bound states also leads to a light-front cluster
decomposition of form factors for an arbitrary number of constituents. The
remarkable analytical structure which follows incorporates the correct scaling
behavior at high photon virtualities and also vector dominance at low energies.


title:
Simulation Results of User Behavior-Aware Scheduling Based on
  Time-Frequency Resource Conversion

abstract:
  Integrating time-frequency resource conversion (TFRC), a new network resource
allocation strategy, with call admission control can not only increase the cell
capacity but also reduce network congestion effectively. However, the optimal
setting of TFRC-oriented call admission control suffers from the curse of
dimensionality, due to Markov chain-based optimization in a high-dimensional
space. To address the scalability issue of TFRC, in [1] we extend the study of
TFRC into the area of scheduling. Specifically, we study downlink scheduling
based on TFRC for an LTE-type cellular network, to maximize service delivery.
The service scheduling of interest is formulated as a joint request, channel
and slot allocation problem which is NP-hard. An offline deflation and
sequential fixing based algorithm (named DSFRB) with only polynomial-time
complexity is proposed to solve the problem. For practical online
implementation, two TFRC-enabled low-complexity algorithms, modified Smith
ratio algorithm (named MSR) and modified exponential capacity algorithm (named
MEC), are proposed as well. In this report, we present detailed numerical
results of the proposed offline and online algorithms, which not only show the
effectiveness of the proposed algorithms but also corroborate the advantages of
the proposed TFRC-based schedule techniques in terms of quality-of-service
(QoS) provisioning for each user and revenue improvement for a service
operator.


title: Natural Inflation with Hidden Scale Invariance

abstract:
  We propose a new class of natural inflation models based on a hidden scale
invariance. In a very generic Wilsonian effective field theory with an
arbitrary number of scalar fields, which exhibits scale invariance via the
dilaton, the potential necessarily contains a flat direction in the classical
limit. This flat direction is lifted by small quantum corrections and inflation
is realised without need for an unnatural fine-tuning. In the conformal limit,
the effective potential becomes linear in the inflaton field, yielding to
specific predictions for the spectral index and the tensor-to-scalar ratio,
being respectively: $n_s-1\approx -0.025\left(\frac{N_{\star}}{60}\right)^{-1}$
and $r\approx 0.0667\left(\frac{N_{\star}}{60}\right)^{-1}$, where
$N_{\star}\approx 30-65$ is a number of efolds during observable inflation.
This predictions are in reasonable agreement with cosmological measurements.
Further improvement of the accuracy of these measurements may turn out to be
critical in falsifying our scenario.


title: Multifactor Risk Models and Heterotic CAPM

abstract:
  We give a complete algorithm and source code for constructing general
multifactor risk models (for equities) via any combination of style factors,
principal components (betas) and/or industry factors. For short horizons we
employ the Russian-doll risk model construction to obtain a nonsingular factor
covariance matrix. This generalizes the heterotic risk model construction to
include arbitrary non-industry risk factors as well as industry risk factors
with generic "weights". The aim of sharing our proprietary know-how with the
investment community is to encourage organic risk model building. The
presentation is intended to be essentially self-contained and pedagogical. So,
stop wasting money and complaining, start building risk models and enjoy!


title:
Total absorption of visible light in ultra-thin weakly-absorbing
  semiconductor gratings

abstract:
  The perfect absorption of light in subwavelength thickness layers generally
relies on exotic materials, metamaterials or thick metallic gratings. Here we
demonstrate that total light absorption can be achieved in ultra-thin gratings
composed of conventional materials, including relatively weakly-absorbing
semiconductors, which are compatible with optoelectronic applications such as
photodetectors and optical modulators. We fabricate a 41 nm thick antimony
sulphide grating structure that has a measured absorptance of A = 99.3% at a
visible wavelength of 591 nm, in excellent agreement with theory. We infer that
the absorption within the grating is A = 98.7%, with only A = 0.6% within the
silver mirror. A planar reference sample absorbs A = 7.7% at this wavelength.