title:
A general theory of linear cosmological perturbations: scalar-tensor and
  vector-tensor theories

abstract:
  We present a method for parametrizing linear cosmological perturbations of
theories of gravity, around homogeneous and isotropic backgrounds. The method
is sufficiently general and systematic that it can be applied to theories with
any degrees of freedom (DoFs) and arbitrary gauge symmetries. In this paper, we
focus on scalar-tensor and vector-tensor theories, invariant under linear
coordinate transformations. In the case of scalar-tensor theories, we use our
framework to recover the simple parametrizations of linearized Horndeski and
"Beyond Horndeski" theories, and also find higher-derivative corrections. In
the case of vector-tensor theories, we first construct the most general
quadratic action for perturbations that leads to second-order equations of
motion, which propagates two scalar DoFs. Then we specialize to the case in
which the vector field is time-like (\`a la Einstein-Aether gravity), where the
theory only propagates one scalar DoF. As a result, we identify the complete
forms of the quadratic actions for perturbations, and the number of free
parameters that need to be defined, to cosmologically characterize these two
broad classes of theories.


title:
The impact of stellar feedback on hot gas in galaxy haloes: the
  Sunyaev-Zel'dovich effect and soft X-ray emission

abstract:
  The thermal Sunyaev-Zel'dovich (SZ) effect and soft X-ray emission are
routinely observed around massive galaxies and in galaxy groups and clusters.
We study these observational diagnostics of galaxy haloes for a suite of
cosmological `zoom-in' simulations from the `Feedback In Realistic
Environments' project, which spans a large range in halo mass 10^10-10^13
Msun). We explore the effect of stellar feedback on the hot gas observables.
The properties of our simulated groups, such as baryon fractions, SZ flux, and
X-ray luminosities (L_X), are broadly consistent with existing observations,
even though feedback from active galactic nuclei is not included. We make
predictions for future observations of lower-mass objects for both SZ and
diffuse X-ray measurements, finding that they are not just scaled-down versions
of massive galaxies, but more strongly affected by galactic winds driven by
star formation. Low-mass haloes (<~10^11 Msun) retain a low fraction of their
baryons, which results in a strong suppression of the SZ signal. Our
simulations therefore predict a scaling with halo mass that is steeper than
self-similar for haloes less massive than 10^13 Msun. For halo masses <~10^12
Msun, L_X is time-variable and correlated primarily with the star formation
rate (SFR). For these objects, the diffuse X-ray emission is powered mostly by
galactic winds and the gas dominating the X-ray emission is flowing out with
radial velocities close to the halo's circular velocity. For halo masses
>~10^13 Msun, on the other hand, L_X is much less variable and not correlated
with the SFR, because the emission originates from the quasi-hydrostatic,
virialized halo gas.


title: Tilted Dirac Fermions

abstract:
  We introduce the notion of a band-inverted, topological semimetal in
two-dimensional nonsymmorphic crystals. This notion is materialized in the
monolayers of MTe$_2$ (M $=$ W, Mo) if spin-orbit coupling is neglected. We
characterize the Dirac band touching topologically by the Wilson loop of the
non-Abelian Berry gauge field. An additional feature of the Dirac cone in
monolayer MTe$_2$ is that it tilts over in a Lifshitz transition to produce
electron and hole pockets, a type-II Dirac cone. These pockets, together with
the pseudospin structure of the Dirac electrons, suggest a unified, topological
explanation for the recently-reported, non-saturating magnetoresistance in
WTe$_2$, as well as its circular dichroism in photoemission. We complement our
analysis and first-principle bandstructure calculations with an
$\textit{ab-initio}$-derived-derived tight-binding model for the WTe$_2$
monolayer.


title:
Magnetic field evolution in magnetar crusts through three dimensional
  simulations

abstract:
  Current models of magnetars require extremely strong magnetic fields to
explain their observed quiescent and bursting emission, implying that the field
strength within the star's outer crust is orders of magnitude larger than the
dipole component inferred from spin-down measurements. This presents a serious
challenge to theories of magnetic field generation in a proto-neutron star.
Here, we present detailed modelling of the evolution of the magnetic field in
the crust of a neutron star through 3-D simulations. We find that, in the
plausible scenario of equipartition of energy between global-scale poloidal and
toroidal magnetic components, magnetic instabilities transfer energy to
non-axisymmetric, kilometre-sized magnetic features, in which the local field
strength can greatly exceed that of the global-scale field. These intense
small-scale magnetic features can induce high energy bursts through local crust
yielding, and the localised enhancement of Ohmic heating can power the star's
persistent emission. Thus, the observed diversity in magnetar behaviour can be
explained with mixed poloidal-toroidal fields of comparable energies.


title: A 17-billion-solar-mass black hole in a group galaxy with a diffuse core

abstract:
  Quasars are associated with and powered by the accretion of material onto
massive black holes; the detection of highly luminous quasars with redshifts
greater than z = 6 suggests that black holes of up to ten billion solar masses
already existed 13 billion years ago. Two possible present-day dormant
descendants of this population of active black holes have been found in the
galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy
clusters, which together form the central region of the Great Wall - the
largest local structure of galaxies. The most luminous quasars, however, are
not confined to such high-density regions of the early Universe; yet dormant
black holes of this high mass have not yet been found outside of modern-day
rich clusters. Here we report observations of the stellar velocity distribution
in the galaxy NGC 1600 - a relatively isolated elliptical galaxy near the
centre of a galaxy group at a distance of 64 Mpc from Earth. We use orbit
superposition models to determine that the black hole at the centre of NGC 1600
has a mass of 17 billion solar masses. The spatial distribution of stars near
the centre of NGC 1600 is rather diffuse. We find that the region of depleted
stellar density in the cores of massive elliptical galaxies extends over the
same radius as the gravitational sphere of influence of the central black
holes, and interpret this as the dynamical imprint of the black holes.


title: A Software Methodology for Compiling Quantum Programs

abstract:
  Quantum computers promise to transform our notions of computation by offering
a completely new paradigm. To achieve scalable quantum computation, optimizing
compilers and a corresponding software design flow will be essential. We
present a software architecture for compiling quantum programs from a
high-level language program to hardware-specific instructions. We describe the
necessary layers of abstraction and their differences and similarities to
classical layers of a computer-aided design flow. For each layer of the stack,
we discuss the underlying methods for compilation and optimization. Our
software methodology facilitates more rapid innovation among quantum algorithm
designers, quantum hardware engineers, and experimentalists. It enables
scalable compilation of complex quantum algorithms and can be targeted to any
specific quantum hardware implementation.


title:
Investigating the Uniformity of the Excess Gamma rays towards the
  Galactic Center Region

abstract:
  We perform a composite likelihood analysis of subdivided regions within the
central $26^\circ\times20^\circ$ of the Milky Way, with the aim of
characterizing the spectrum of the gamma-ray galactic center excess in regions
of varying galactocentric distance. Outside of the innermost few degrees, we
find that the radial profile of the excess is background-model dependent and
poorly constrained. The spectrum of the excess emission is observed to extend
upwards of 10 GeV outside $\sim5^\circ$ in radius, but cuts off steeply between
10--20 GeV only in the innermost few degrees. If interpreted as a real feature
of the excess, this radial variation in the spectrum has important implications
for both astrophysical and dark matter interpretations of the galactic center
excess. Single-component dark matter annihilation models face challenges in
reproducing this variation; on the other hand, a population of unresolved
millisecond pulsars contributing both prompt and secondary inverse Compton
emission may be able to explain the spectrum as well as its spatial dependency.
We show that the expected differences in the photon-count distributions of a
smooth dark matter annihilation signal and an unresolved point source
population are an order of magnitude smaller than the fluctuations in residuals
after fitting the data, which implies that mismodeling is an important
systematic effect in point source analyses aimed at resolving the gamma-ray
excess.


title:
A study of broadband Faraday rotation and polarization behaviour over
  1.3--10 GHz in 36 discrete radio sources

abstract:
  We present a broadband polarization analysis of 36 discrete polarized radio
sources over a very broad, densely-sampled frequency band. Our sample was
selected on the basis of polarization behaviour apparent in narrowband archival
data at 1.4 GHz: half the sample show complicated frequency-dependent
polarization behaviour (i.e. Faraday complexity) at these frequencies, while
half show comparatively simple behaviour (i.e. they appear Faraday simple). We
re-observed the sample using the Australia Telescope Compact Array (ATCA) in
full polarization, with 6 GHz of densely sampled frequency coverage spanning
1.3 to 10 GHz. We have devised a general polarization modelling technique that
allows us to identify multiple polarized emission components in a source, and
to characterize their properties. We detect Faraday complex behaviour in almost
every source in our sample. Several sources exhibit particularly remarkable
polarization behaviour. By comparing our new and archival data, we have
identified temporal variability in the broadband integrated polarization
spectra of some sources. In a number of cases, the characteristics of the
polarized emission components, including the range of Faraday depths over which
they emit, their temporal variability, spectral index, and the linear extent of
the source, allow us to argue that the spectropolarimetric data encodes
information about the magnetoionic environment of active galactic nuclei
themselves. Furthermore, the data place direct constraints on the geometry and
magnetoionic structure of this material. We discuss the consequences of
restricted frequency bands on the detection and interpretation of polarization
structures, and implications for upcoming spectropolarimetric surveys.


title:
Bootstrapping rapidity anomalous dimension for transverse-momentum
  resummation

abstract:
  Soft function relevant for transverse-momentum resummation for Drell-Yan or
Higgs production at hadron colliders are computed through to three loops in the
expansion of strong coupling, with the help of bootstrap technique and
supersymmetric decomposition. The corresponding rapidity anomalous dimension is
extracted. An intriguing relation between anomalous dimensions for
transverse-momentum resummation and threshold resummation is found.


title:
Suppressing supersymmetric flavor violations through quenched
  gaugino-flavor interactions

abstract:
  Realizing that couplings related by supersymmetry (SUSY) can be disentangled
when SUSY is broken, it is suggested that unwanted flavor and CP violating SUSY
couplings may be suppressed via quenched gaugino-flavor interactions, which may
be accomplished by power-law running of sfermion anomalous dimensions. A simple
theoretical framework to accomplish this is exemplified and the defeated
constraints are tallied. One key implication of the scenario is the expectation
of enhanced top, bottom and tau production at the LHC, accompanied by large
missing energy. Also, direct detection signals of dark matter may be more
challenging to find than in conventional SUSY scenarios.


title: Anatomy of Exotic Higgs Decays in 2HDM

abstract:
  Large mass splittings between new scalars in two-Higgs-doublet models (2HDM)
open a key avenue to search for these new states via exotic heavy Higgs decays.
We discuss in detail the different search channels for these new scalars at the
LHC in the presence of a sizable mass splitting, i.e. a hierarchical 2HDM
scenario, taking into account the theoretical and experimental constraints. We
provide benchmark planes to exploit the complementarity among these searches,
analyzing their potential to probe the hierarchical 2HDM parameter space during
LHC Run 2.


title: Updated Kinematic Constraints on a Dark Disk

abstract:
  We update the method of the Holmberg & Flynn (2000) study, including an
updated model of the Milky Way's interstellar gas, radial velocities, an
updated reddening map, and a careful statistical analysis, to bound the allowed
surface density and scale height of a dark disk. We pay careful attention to
the self-consistency of the model, including the gravitational influence of the
dark disk on other disk components, and to the net velocity of the tracer
stars. We find that the data set exhibits a non-zero bulk velocity in the
vertical direction as well as a displacement from the expected location at the
Galactic midplane. If not properly accounted for, these features would bias the
bound toward low dark disk mass. We therefore perform our analysis two ways. In
the first, traditional method, we subtract the mean velocity and displacement
from the tracers' phase space distributions. In the second method, we perform a
non-equilibrium version of the HF method to derive a bound on the dark disk
parameters for an oscillating tracer distribution. Despite updates in the mass
model and reddening map, the traditional method results remain consistent with
those of HF2000. The second, non-equilibrium technique, however, allows a
surface density as large as $14\, M_\odot\,{\rm pc}^{-2}$ (and as small as 0),
demonstrating much weaker constraints. For both techniques, the bound on
surface density is weaker for larger scale height. In future analyses of Gaia
data, it will be important to verify whether the tracer populations are in
equilibrium.


title: High precision radial velocities with GIANO spectra

abstract:
  Radial velocities (RV) measured from near-infrared (NIR) spectra are a
potentially excellent tool to search for extrasolar planets around cool or
active stars. High resolution infrared (IR) spectrographs now available are
reaching the high precision of visible instruments, with a constant improvement
over time. GIANO is an infrared echelle spectrograph at the Telescopio
Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution
spectra for accurate RV measurements of exoplanets and for chemical and
dynamical studies of stellar or extragalactic objects. No other high spectral
resolution IR instrument has GIANO's capability to cover the entire NIR
wavelength range (0.95-2.45 micron) in a single exposure. In this paper we
describe the ensemble of procedures that we have developed to measure high
precision RVs on GIANO spectra acquired during the Science Verification (SV)
run, using the telluric lines as wavelength reference. We used the Cross
Correlation Function (CCF) method to determine the velocity for both the star
and the telluric lines. For this purpose, we constructed two suitable digital
masks that include about 2000 stellar lines, and a similar number of telluric
lines. The method is applied to various targets with different spectral type,
from K2V to M8 stars. We reached different precisions mainly depending on the H
-magnitudes: for H ~ 5 we obtain an rms scatter of ~ 10 m s-1, while for H ~ 9
the standard deviation increases to ~ 50 - 80 m s-1. The corresponding
theoretical error expectations are ~4 m s-1 and 30 m s-1, respectively. Finally
we provide the RVs measured with our procedure for the targets observed during
GIANO Science Verification.


title:
Ubiquity of density slope oscillations in the central regions of galaxy
  and cluster-sized systems

abstract:
  One usually thinks of a radial density profile as having a monotonically
changing logarithmic slope, such as in NFW or Einasto profiles. However, in two
different classes of commonly used systems, this is often not the case. These
classes exhibit non-monotonic changes in their density profile slopes which we
call oscillations for short. We analyze these two unrelated classes separately.
Class 1 consists of systems that have density oscillations and that are defined
through their distribution function $f(E)$, or differential energy distribution
$N(E)$, such as isothermal spheres, King profiles, or DARKexp, a theoretically
derived model for relaxed collisionless systems. Systems defined through $f(E)$
or $N(E)$ generally have density slope oscillations. Class 1 system
oscillations can be found at small, intermediate, or large radii but we focus
on a limited set of Class 1 systems that have oscillations in the central
regions, usually at $\log(r/r_{-2})\lesssim -2$, where $r_{-2}$ is the largest
radius where $d\log(\rho)/d\log(r)=-2$. We show that the shape of their $N(E)$
can roughly predict the amplitude of oscillations. Class 2 systems which are a
product of dynamical evolution, consist of observed and simulated galaxies and
clusters, and pure dark matter halos. Oscillations in the density profile slope
seem pervasive in the central regions of Class 2 systems. We argue that in
these systems, slope oscillations are an indication that a system is not fully
relaxed. We show that these oscillations can be reproduced by small
modifications to $N(E)$ of DARKexp. These affect a small fraction of systems'
mass and are confined to $\log(r/r_{-2})\lesssim 0$. The size of these
modifications serves as a potential diagnostic for quantifying how far a system
is from being relaxed.


title: Spatial curvature endgame: Reaching the limit of curvature determination

abstract:
  Current constraints on spatial curvature show that it is dynamically
negligible: $|\Omega_{\rm K}| \lesssim 5 \times 10^{-3}$ (95% CL). Neglecting
it as a cosmological parameter would be premature however, as more stringent
constraints on $\Omega_{\rm K}$ at around the $10^{-4}$ level would offer
valuable tests of eternal inflation models and probe novel large-scale
structure phenomena. This precision also represents the "curvature floor",
beyond which constraints cannot be meaningfully improved due to the cosmic
variance of horizon-scale perturbations. In this paper, we discuss what future
experiments will need to do in order to measure spatial curvature to this
maximum accuracy. Our conservative forecasts show that the curvature floor is
unreachable - by an order of magnitude - even with Stage IV experiments, unless
strong assumptions are made about dark energy evolution and the $\Lambda$CDM
parameter values. We also discuss some of the novel problems that arise when
attempting to constrain a global cosmological parameter like $\Omega_{\rm K}$
with such high precision. Measuring curvature down to this level would be an
important validation of systematics characterisation in high-precision
cosmological analyses.


title:
Spectroscopic characterization of HD 95086 b with the Gemini Planet
  Imager

abstract:
  We present new $H$ (1.5-1.8 $\mu$m) photometric and $K_1$ (1.9-2.2 $\mu$m)
spectroscopic observations of the young exoplanet HD 95086 b obtained with the
Gemini Planet Imager. The $H$-band magnitude has been significantly improved
relative to previous measurements, whereas the low resolution $K_1$
($\lambda/\delta\lambda \approx 66$) spectrum is featureless within the
measurement uncertainties, and presents a monotonically increasing
pseudo-continuum consistent with a cloudy atmosphere. By combining these new
measurements with literature $L^{\prime}$ photometry, we compare the spectral
energy distribution of the planet to other young planetary-mass companions,
field brown dwarfs, and to the predictions of grids of model atmospheres. HD
95086 b is over a magnitude redder in $K_1-L^{\prime}$ color than 2MASS
J12073346-3932539 b and HR 8799 c and d, despite having a similar $L^{\prime}$
magnitude. Considering only the near-infrared measurements, HD 95086 b is most
analogous to the brown dwarfs 2MASS J2244316+204343 and 2MASS
J21481633+4003594, both of which are thought to have dusty atmospheres.
Morphologically, the spectral energy distribution of HD 95086 b is best fit by
low temperature ($T_{\rm eff} =$ 800-1300 K), low surface gravity spectra from
models which simulate high photospheric dust content. This range of effective
temperatures is consistent with field L/T transition objects, but the spectral
type of HD 95086 b is poorly constrained between early L and late T due to its
unusual position the color-magnitude diagram, demonstrating the difficulty in
spectral typing young, low surface gravity substellar objects. As one of the
reddest such objects, HD 95086 b represents an important empirical benchmark
against which our current understanding of the atmospheric properties of young
extrasolar planets can be tested.


title: Measurement of the mass and lifetime of the $\Omega_b^-$ baryon

abstract:
  A proton-proton collision data sample, corresponding to an integrated
luminosity of 3 fb$^{-1}$ collected by LHCb at $\sqrt{s}=7$ and 8 TeV, is used
to reconstruct $63\pm9$ $\Omega_b^-\to\Omega_c^0\pi^-$, $\Omega_c^0\to
pK^-K^-\pi^+$ decays. Using the $\Xi_b^-\to\Xi_c^0\pi^-$, $\Xi_c^0\to
pK^-K^-\pi^+$ decay mode for calibration, the lifetime ratio and absolute
lifetime of the $\Omega_b^-$ baryon are measured to be \begin{align*}
\frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\
\tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the
uncertainties are statistical, systematic and from the calibration mode (for
$\tau_{\Omega_b^-}$ only). A measurement is also made of the mass difference,
$m_{\Omega_b^-}-m_{\Xi_b^-}$, and the corresponding $\Omega_b^-$ mass, which
yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm
MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2.
\end{align*} These results are consistent with previous measurements.


title: Doppler Monitoring of five K2 Transiting Planetary Systems

abstract:
  In an effort to measure the masses of planets discovered by the NASA {\it K2}
mission, we have conducted precise Doppler observations of five stars with
transiting planets. We present the results of a joint analysis of these new
data and previously published Doppler data. The first star, an M dwarf known as
K2-3 or EPIC~201367065, has three transiting planets ("b", with radius
$2.1~R_{\oplus}$; "c", $1.7~R_{\oplus}$; and "d", $1.5~R_{\oplus}$). Our
analysis leads to the mass constraints: $M_{b}=8.1^{+2.0}_{-1.9}~M_{\oplus}$
and $M_{c}$ < $ 4.2~M_{\oplus}$~(95\%~conf.). The mass of planet d is poorly
constrained because its orbital period is close to the stellar rotation period,
making it difficult to disentangle the planetary signal from spurious Doppler
shifts due to stellar activity. The second star, a G dwarf known as K2-19 or
EPIC~201505350, has two planets ("b", $7.7~R_{\oplus}$; and "c",
$4.9~R_{\oplus}$) in a 3:2 mean-motion resonance, as well as a shorter-period
planet ("d", $1.1~R_{\oplus}$). We find $M_{b}$= $28.5^{+5.4}_{-5.0}
~M_{\oplus}$, $M_{c}$= $25.6^{+7.1}_{-7.1} ~M_{\oplus}$ and $M_{d}$ <
$14.0~M_{\oplus} $~(95\%~conf.). The third star, a G dwarf known as K2-24 or
EPIC~203771098, hosts two transiting planets ("b", $5.7~R_{\oplus}$; and "c",
$7.8~R_{\oplus}$) with orbital periods in a nearly 2:1 ratio. We find $M_{b}$=
$19.8^{+4.5}_{-4.4} ~M_{\oplus}$ and $M_{c}$ =
$26.0^{+5.8}_{-6.1}~M_{\oplus}$.....


title:
On the splitting of infinitesimal Poisson automorphisms around
  symplectic leaves

abstract:
  A geometric description of the first Poisson cohomology groups is given in
the semilocal context, around (possibly singular) symplectic leaves. This
result is based on the splitting theorems for infinitesimal automorphisms of
coupling Poisson structures which describe the interaction between the
tangential and transversal data of the characteristic distributions. As a
consequence, we derive some criteria of vanishing of the first Poisson
cohomology groups and apply the general splitting formulas to some particular
classes of Poisson structures associated with singular symplectic foliations.


title: Containment and resolution of hadronic showers at the FCC

abstract:
  The particles produced at a potential Future Circular Collider with
$\sqrt{s}$ = 100 TeV are of unprecented energies. In this document we present
the hadronic shower containment and resolution parametrizations based on Geant4
simulations for the Hadronic calorimetry needed for conceptual detector design
at this energy. The Geant4 toolkit along with FTFP\_BERT physics list are used
in this study. Comparisons are made with test-beam data from the ATLAS Tile
hadronic calorimeter. These simulations motivate a 12 $\lambda$ calorimeter in
order to contain at 98% level TeV single hadron showers and multi-TeV jets and
keep a pion energy resolution constant term of 3%.


title:
dMath: A Scalable Linear Algebra and Math Library for Heterogeneous
  GP-GPU Architectures

abstract:
  A new scalable parallel math library, dMath, is presented in this paper that
demonstrates leading scaling when using intranode, or internode,
hybrid-parallelism for deep-learning. dMath provides easy-to-use distributed
base primitives and a variety of domain-specific algorithms. These include
matrix multiplication, convolutions, and others allowing for rapid development
of highly scalable applications, including Deep Neural Networks (DNN), whereas
previously one was restricted to libraries that provided effective primitives
for only a single GPU, like Nvidia cublas and cudnn or DNN primitives from
Nervana neon framework. Development of HPC software is difficult,
labor-intensive work, requiring a unique skill set. dMath allows a wide range
of developers to utilize parallel and distributed hardware easily. One
contribution of this approach is that data is stored persistently on the GPU
hardware, avoiding costly transfers between host and device. Advanced memory
management techniques are utilized, including caching of transferred data and
memory reuse through pooling. A key contribution of dMath is that it delivers
performance, portability, and productivity to its specific domain of support.
It enables algorithm and application programmers to quickly solve problems
without managing the significant complexity associated with multi-level
parallelism.


title: Device-Independent Certification of a Nonprojective Qubit Measurement

abstract:
  Quantum measurements on a two-level system can have more than two independent
outcomes, and in this case, the measurement cannot be projective. Measurements
of this general type are essential to an operational approach to quantum
theory, but so far, the nonprojective character of a measurement can only be
verified experimentally by already assuming a specific quantum model of parts
of the experimental setup. Here, we overcome this restriction by using a
device-independent approach. In an experiment on pairs of
polarization-entangled photonic qubits we violate by more than 8 standard
deviations a Bell-like correlation inequality that is valid for all sets of
two-outcome measurements in any dimension. We combine this with a
device-independent verification that the system is best described by two
qubits, which therefore constitutes the first device-independent certification
of a nonprojective quantum measurement.


title: MUFASA: Galaxy Formation Simulations With Meshless Hydrodynamics

abstract:
  We present the MUFASA suite of cosmological hydrodynamic simulations, which
employs the GIZMO meshless finite mass (MFM) code including H2-based star
formation, nine-element chemical evolution, two-phase kinetic outflows
following scalings from the Feedback in Realistic Environments zoom
simulations, and evolving halo mass-based quenching. Our fiducial (50 Mpc/h)^3
volume is evolved to z=0 with a quarter billion particles, The predicted galaxy
stellar mass functions (GSMF) reproduce observations from z=4-0 to <1.2sigma in
cosmic variance, providing an unprecedented match to this key diagnostic. The
cosmic star formation history and stellar mass growth show general agreement
with data, with a strong archaeological downsizing trend such that dwarf
galaxies form the majority of their stars after z~1. We run 25 Mpc/h and 12.5
Mpc/h volumes to z=2 with identical feedback prescriptions, the latter
resolving all hydrogen-cooling halos, and the three runs display fair
resolution convergence. The specific star formation rates broadly agree with
data at z=0, but are underpredicted at z~2 by a factor of three, re-emphasizing
a longstanding puzzle in galaxy evolution models. We compare runs using MFM and
two flavours of Smoothed Particle Hydrodynamics, and show that the GSMF is
sensitive to hydrodynamics methodology at the ~x2 level, which is sub-dominant
to choices for parameterising feedback.


title:
Impact of Future Lepton Flavor Violation Measurements in the Minimal
  Supersymmetric Standard Model

abstract:
  Working within the context of the minimal supersymmetric standard model, we
compare current bounds from quark flavor changing processes with current and
upcoming bounds on lepton flavor violation. We assume supersymmetry breaking
approximately respects CP invariance. Under the further assumption that flavor
violating insertions in the quark and lepton scalar masses are comparable, we
explore when lepton flavor violation provides the strongest probe of new
physics. We quote results both for spectra with all superpartners near the TeV
scale and where scalars are multi-TeV. Constraints from quark flavor changing
neutral currents are in many cases already stronger than those expected from
future lepton flavor violation bounds, but large regions of parameter space
remain where the latter could provide a discovery mode for supersymmetry.


title: Highly accurate gaze estimation using a consumer RGB-depth sensor

abstract:
  Determining the direction in which a person is looking is an important
problem in a wide range of HCI applications. In this paper we describe a highly
accurate algorithm that performs gaze estimation using an affordable and widely
available device such as Kinect. The method we propose starts by performing
accurate head pose estimation achieved by fitting a person specific morphable
model of the face to depth data. The ordinarily competing requirements of high
accuracy and high speed are met concurrently by formulating the fitting
objective function as a combination of terms which excel either in accurate or
fast fitting, and then by adaptively adjusting their relative contributions
throughout fitting. Following pose estimation, pose normalization is done by
re-rendering the fitted model as a frontal face. Finally gaze estimates are
obtained through regression from the appearance of the eyes in synthetic,
normalized images. Using EYEDIAP, the standard public dataset for the
evaluation of gaze estimation algorithms from RGB-D data, we demonstrate that
our method greatly outperforms the state of the art.


title:
Partial Sublinear Time Approximation and Inapproximation for Maximum
  Coverage

abstract:
  We develop a randomized approximation algorithm for the classical maximum
coverage problem, which given a list of sets $A_1,A_2,\cdots, A_m$ and integer
parameter $k$, select $k$ sets $A_{i_1}, A_{i_2},\cdots, A_{i_k}$ for maximum
union $A_{i_1}\cup A_{i_2}\cup\cdots\cup A_{i_k}$. In our algorithm, each input
set $A_i$ is a black box that can provide its size $|A_i|$, generate a random
element of $A_i$, and answer the membership query $(x\in A_i?)$ in $O(1)$ time.
Our algorithm gives $(1-{1\over e})$-approximation for maximum coverage problem
in $O(p(m))$ time, which is independent of the sizes of the input sets. No
existing $O(p(m)n^{1-\epsilon})$ time $(1-{1\over e})$-approximation algorithm
for the maximum coverage has been found for any function $p(m)$ that only
depends on the number of sets, where $n=\max(|A_1|,\cdots,| A_m|)$ (the largest
size of input sets). The notion of partial sublinear time algorithm is
introduced. For a computational problem with input size controlled by two
parameters $n$ and $m$, a partial sublinear time algorithm for it runs in a
$O(p(m)n^{1-\epsilon})$ time or $O(q(n)m^{1-\epsilon})$ time. The maximum
coverage has a partial sublinear time $O(p(m))$ constant factor approximation.
On the other hand, we show that the maximum coverage problem has no partial
sublinear $O(q(n)m^{1-\epsilon})$ time constant factor approximation algorithm.
It separates the partial sublinear time computation from the conventional
sublinear time computation by disproving the existence of sublinear time
approximation algorithm for the maximum coverage problem.


title:
Convergence of MCMC and Loopy BP in the Tree Uniqueness Region for the
  Hard-Core Model

abstract:
  We study the hard-core model defined on independent sets of an input graph
where the independent sets are weighted by a parameter $\lambda>0$. For
constant $\Delta$, previous work of Weitz (2006) established an FPTAS for the
partition function for graphs of maximum degree $\Delta$ when $\lambda<
\lambda_c(\Delta)$. The threshold $\lambda_c(\Delta)$ is the critical point for
the phase transition for uniqueness/non-uniqueness on the infinite
$\Delta$-regular trees. Sly (2010) showed that there is no FPRAS, unless NP=RP,
when $\lambda>\lambda_c(\Delta)$. The running time of Weitz's algorithm is
exponential in $\log(\Delta)$. Here we present an FPRAS for the partition
function whose running time is $O^*(n^2)$. We analyze the simple single-site
Glauber dynamics for sampling from the associated Gibbs distribution. We prove
there exists a constant $\Delta_0$ such that for all graphs with maximum degree
$\Delta\geq\Delta_0$ and girth $\geq 7$, the mixing time of the Glauber
dynamics is $O(n\log(n))$ when $\lambda<\lambda_c(\Delta)$. Our work
complements that of Weitz which applies for constant $\Delta$ whereas our work
applies for all $\Delta \geq \Delta_0$.
  We utilize loopy BP (belief propagation), a widely-used inference algorithm.
A novel aspect of our work is using the principal eigenvector for the BP
operator to design a distance function which contracts in expectation for pairs
of states that behave like the BP fixed point. We also prove that the Glauber
dynamics behaves locally like loopy BP. As a byproduct we obtain that the
Glauber dynamics converges, after a short burn-in period, close to the BP fixed
point, and this implies that the fixed point of loopy BP is a close
approximation to the Gibbs distribution. Using these connections we establish
that loopy BP quickly converges to the Gibbs distribution when the girth $\geq
6$ and $\lambda<\lambda_c(\Delta)$.


title:
Direct numerical solution of the two-particle Lippmann-Schwinger
  equation in coordinate space using the multi-variable Nystrom method

abstract:
  Direct numerical solution of the coordinate-space integral-equation version
of the two-particle Lippmann Schwinger (LS) equation is considered as a means
of avoiding the shortcomings of partial-wave expansion at high energies and in
the context of few-body problems. Upon the regularization of the singular
kernel of the three-dimensional LS equation by a subtraction technique, a
three-variate quadrature rule is used to solve the resulting nonsingular
integral equation. To avoid the computational burden of discretizing three
variables, advantage is taken of the fact that, for central potentials,
azimuthal angle can be integrated out leaving a two-variable reduced integral
equation. Although the singularity in the the kernel of the two-variable
integral equation is weaker than that of the three-dimensional equation, it
nevertheless requires careful handling for quadrature discretization to be
applicable. A regularization method for the kernel of the two-variable integral
equation is derived from the treatment of the singularity in the
three-dimensional equation. A quadrature rule constructed as the direct-product
of single-variable quadrature rules for radial distance and polar angle is used
to discretize the two-variable integral equation. These two- and three-variable
methods are tested on a model nucleon-nucleon potential. The results show that
Nystrom method for the coordinate-space LS equation compares favorably in terms
of its ease of implementation and effectiveness with the Nystrom method for the
momentum-space version of the LS equation .


title: A 2.4% Determination of the Local Value of the Hubble Constant

abstract:
  We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to
reduce the uncertainty in the local value of the Hubble constant (H_0) from
3.3% to 2.4%. Improvements come from new, near-infrared observations of Cepheid
variables in 11 new hosts of recent SNe~Ia, more than doubling the sample of
SNe~Ia having a Cepheid-calibrated distance for a total of 19; these leverage
the magnitude-z relation based on 300 SNe~Ia at z<0.15. All 19 hosts and the
megamaser system NGC4258 were observed with WFC3, thus nullifying
cross-instrument zeropoint errors. Other improvements include a 33% reduction
in the systematic uncertainty in the maser distance to NGC4258, more Cepheids
and a more robust distance to the LMC from late-type DEBs, HST observations of
Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW)
Cepheids. We consider four geometric distance calibrations of Cepheids: (i)
megamasers in NGC4258, (ii) 8 DEBs in the LMC, (iii) 15 MW Cepheids with
parallaxes, and (iv) 2 DEBs in M31. H_0 from each is 72.25+/-2.51,
72.04+/-2.67, 76.18+/-2.37, and 74.50+/-3.27 km/sec/Mpc, respectively. Our best
estimate of 73.24+/-1.74 km/sec/Mpc combines the anchors NGC4258, MW, and LMC,
and includes systematic errors for a final uncertainty of 2.4%. This value is
3.4 sigma higher than 66.93+/-0.62 km/sec/Mpc predicted by LambdaCDM with 3
neutrinos with mass 0.06 eV and the Planck data, but reduces to 2.1 sigma
relative to the prediction of 69.3+/-0.7 km/sec/Mpc with the combination of
WMAP+ACT+SPT+BAO, suggesting systematic uncertainties in CMB measurements may
play a role in the tension. If we take the conflict between Planck and H_0 at
face value, one plausible explanation could involve an additional source of
dark radiation in the early Universe in the range of Delta N_eff=0.4-1. We
anticipate significant improvements in H_0 from upcoming parallax measurements.


title:
Study on the Thickness Change of Nickel-Plated Layer in Fabrication of
  the Silver Hollow Nickel Waveguides by the Outer-Coating Method of the Liquid
  Phase Process

abstract:
  A metallic hollow waveguide is promising fiber for the delivery of laser
radiation. Thickness of the nickel plated layer for supporting of the waveguide
in fabrication of a dielectric coated silver hollow nickel waveguide is very
important factor. In this paper, the change characteristic in the thickness of
the nickel plated layer along the length of the silver coated glass mandrel
during fabricating the silver hollow nickel waveguide by the outer-coating
method of the liquid phase process has been studied both experimentally and
analytically. Waveguides with uniform thickness of the nickel plated layer
along the length of the silver coated glass mandrel have been fabricated.


title:
UV-photoelectric effect for augmented contrast and resolution in
  electron microscopy

abstract:
  A new tool providing material contrast control in scanning electron
microscopy (SEM) is demonstrated. The approach is based on deep-UV illumination
during SEM imaging and delivers a novel material based contrast as well as
higher resolution due to the photoelectric effect. Electrons liberated from
illuminated sample surface contribute to the imaging which can be carried out
at a faster acquisition rate, provide material selective contrast, reduce
distortions caused by surface charging, and can substitute metal coating in
SEM. These features provide high fidelity SEM imaging and are expected to
significantly improve the performance of electron beam instruments as well as
to open new opportunities for imaging and characterization of materials at the
nanoscale.


title:
Basic Theoretical Model and Sampling Criteria for Time-Interleaved
  Photonic Analog-to-Digital Converters

abstract:
  In this paper, we present a basic model for time-interleaved photonic
analog-to-digital converter (TIPADC) and analyze its linear, nonlinear, and
noise performance. The basic operation mechanism of TIPADC is illustrated and
the linear performance is analyzed in frequency domain. The mathematical
expressions and the output of the system are presented in each processing step.
We reveal that photonic sampling folds the whole spectrum of input signal in a
narrow band, which enables the analog bandwidth of a TIPADC to be much higher
than the bandwidth of back-end electronics. The feasible regions of the system
is obtained in terms of system frequency response, and a set of sampling
criteria determining the basic requirements to the system are summarized for
typical applications. The results show that the global minimum feasible
bandwidth of back-end electronics is the half of single channel sampling rate
when the bandwidth of photonic sampling pulse is comparable to input signal
frequency. The amplitude and phase noise of photonic sampling pulse train, the
thermal noise and shot noise of photodetection, and the quantization noise and
aperture jitter noise of EADCs are investigated. The nonlinearity of TIPADC is
also analyzed. The effect of different factors, such as the single channel
sampling rate, the average optical power and the bandwidth of back-end
electronics, on the effective number of bits of TIPADC is qualitatively and
quantitatively discussed. The results explicitly show that TIPADC can perform
high fidelity conversion to ultra-high speed analog signal and overcome the
major performance limitations existing in traditional ADCs such as aperture
jitter and bandwidth. The criteria deduced will be an effective supplement to
the generalized sampling theorem in designing TIPADC.


title: S-hull: a fast radial sweep-hull routine for Delaunay triangulation

abstract:
  A new O(nlog(n)) algorithm is presented for performing Delaunay triangulation
of sets of 2D points. The novel component of the algorithm is a radially
propagating \emph{sweep-hull} (sequentially created from the radially sorted
set of 2D points, giving a non-overlapping triangulation), paired with a final
triangle flipping step to give the Delaunay triangluation.
  In empirical tests the algorithm runs in approximately half the time of
q-hull for 2D Delaunay triangulation on randomly generated point sets.


title: The Price of Differential Privacy for Low-Rank Factorization

abstract:
  In this paper, we study what price one has to pay to release {\em
differentially private low-rank factorization} of a matrix. We consider various
settings that are close to the real world applications of low-rank
factorization: (i) the manner in which matrices are updated (row by row or in
an arbitrary manner), (ii) whether matrices are distributed or not, and (iii)
how the output is produced (once at the end of all updates, also known as {\em
one-shot algorithms} or continually). Even though these settings are well
studied without privacy, surprisingly, there are no private algorithm for these
settings (except when a matrix is updated row by row). We present the first set
of differentially private algorithms for all these settings.
  Our algorithms when private matrix is updated in an arbitrary manner promise
differential privacy with respect to two stronger privacy guarantees than
previously studied, use space and time {\em comparable} to the non-private
algorithm, and achieve {\em optimal accuracy}. To complement our positive
results, we also prove that the space required by our algorithms is optimal up
to logarithmic factors. When data matrices are distributed over multiple
servers, we give a non-interactive differentially private algorithm with
communication cost independent of dimension. In concise, we give algorithms
that incur optimal cost. We also perform experiments to verify that all our
algorithms perform well in practice and outperform the best known algorithms
until now for large range of parameters. We give experimental results for total
approximation error and additive error for varying dimensions, $\alpha$ and
$k$.


title: Blending stiffness and strength disorder can stabilize fracture

abstract:
  Quasi-brittle behavior where macroscopic failure is preceded by stable
damaging and intensive cracking activity is a desired feature of materials
because it makes fracture predictable. Based on a fiber bundle model with
global load sharing we show that blending strength and stiffness disorder of
material elements leads to the stabilization of fracture, i.e. samples which
are brittle when one source of disorder is present, become quasi-brittle as a
consequence of blending. We derive a condition of quasi-brittle behavior in
terms of the joint distribution of the two sources of disorder. Breaking bursts
have a power law size distribution of exponent 5/2 without any crossover to a
lower exponent when the amount of disorder is gradually decreased. The results
have practical relevance for the design of materials to increase the safety of
constructions.


title: Forecasting Interactive Dynamics of Pedestrians with Fictitious Play

abstract:
  We develop predictive models of pedestrian dynamics by encoding the coupled
nature of multi-pedestrian interaction using game theory, and deep
learning-based visual analysis to estimate person-specific behavior parameters.
Building predictive models for multi-pedestrian interactions however, is very
challenging due to two reasons: (1) the dynamics of interaction are complex
interdependent processes, where the predicted behavior of one pedestrian can
affect the actions taken by others and (2) dynamics are variable depending on
an individuals physical characteristics (e.g., an older person may walk slowly
while the younger person may walk faster). To address these challenges, we (1)
utilize concepts from game theory to model the interdependent decision making
process of multiple pedestrians and (2) use visual classifiers to learn a
mapping from pedestrian appearance to behavior parameters. We evaluate our
proposed model on several public multiple pedestrian interaction video
datasets. Results show that our strategic planning model explains human
interactions 25% better when compared to state-of-the-art methods.


title:
An application of John ellipsoids to the Szego kernel on unbounded
  convex domains

abstract:
  We use convex geometry tools, in particular John ellipsoids, to obtain a size
estimate for the Szeg\H{o} kernel on the boundary of a class of unbounded
convex domains in $\mathbb{C}^n.$ Given a polynomial $b:\mathbb{R}^n
\rightarrow \mathbb{R}$ satisfying a certain growth condition, we consider
domains of the type $\Omega_b = \{ z\in\mathbb{C}^{n+1}\,:\, {\rm Im}[z_{n+1}]
> b({\rm Re}[z_1],\ldots,{\rm Re}[z_n]) \}.$


title: Collaborative Information Bottleneck

abstract:
  This paper investigates a multi-terminal source coding problem under a
logarithmic loss fidelity which does not necessarily lead to an additive
distortion measure. The problem is motivated by an extension of the Information
Bottleneck method to a multi-source scenario where several encoders have to
build cooperatively rate-limited descriptions of their sources in order to
maximize information with respect to other unobserved (hidden) sources. More
precisely, we study fundamental information-theoretic limits of the so-called:
(i) Two-way Collaborative Information Bottleneck (TW-CIB) and (ii) the
Collaborative Distributed Information Bottleneck (CDIB) problems. The TW-CIB
problem consists of two distant encoders that separately observe marginal
(dependent) components $X_1$ and $X_2$ and can cooperate through multiple
exchanges of limited information with the aim of extracting information about
hidden variables $(Y_1,Y_2)$, which can be arbitrarily dependent on
$(X_1,X_2)$. On the other hand, in CDIB there are two cooperating encoders
which separately observe $X_1$ and $X_2$ and a third node which can listen to
the exchanges between the two encoders in order to obtain information about a
hidden variable $Y$. The relevance (figure-of-merit) is measured in terms of a
normalized (per-sample) multi-letter mutual information metric (log-loss
fidelity) and an interesting tradeoff arises by constraining the complexity of
descriptions, measured in terms of the rates needed for the exchanges between
the encoders and decoders involved. Inner and outer bounds to the
complexity-relevance region of these problems are derived from which optimality
is characterized for several cases of interest. Our resulting theoretical
complexity-relevance regions are finally evaluated for binary symmetric and
Gaussian statistical models.


title: A General Formula for Compound Channel Capacity

abstract:
  A general formula for the capacity of arbitrary compound channels with the
receiver channel state information is obtained using the information density
approach. No assumptions of ergodicity, stationarity or information stability
are made and the channel state set is arbitrary. A direct (constructive) proof
is given. To prove achievability, we generalize Feinstein Lemma to the compound
channel setting, and to prove converse, we generalize Verdu-Han Lemma to the
same compound setting. A notion of a uniform compound channel is introduced and
the general formula is shown to reduce to the familiar $\sup-\inf$ expression
for such channels. As a by-product, the arbitrary varying channel capacity is
established under maximum error probability and deterministic coding.
Conditions are established under which the worst-case and compound channel
capacities are equal so that the full channel state information at the
transmitter brings in no advantage.
  The compound inf-information rate plays a prominent role in the general
formula. Its properties are studied and a link between information-unstable and
information-stable regimes of a compound channel is established. The results
are extended to include $\varepsilon$-capacity of compound channels. Sufficient
and necessary conditions for the strong converse to hold are given.


title:
Approximation Algorithms for Max-Min Share Allocations of Indivisible
  Chores and Goods

abstract:
  We consider Max-min Share (MmS) allocations of items both in the case where
items are goods (positive utility) and when they are chores (negative utility).
We show that fair allocations of goods and chores have some fundamental
connections but differences as well. We prove that like in the case for goods,
an MmS allocation does not need to exist for chores and computing an MmS
allocation - if it exists - is strongly NP-hard. In view of these non-existence
and complexity results, we present a polynomial-time 2-approximation algorithm
for MmS fairness for chores. We then introduce a new fairness concept called
optimal MmS that represents the best possible allocation in terms of MmS that
is guaranteed to exist. For both goods and chores, we use connections to
parallel machine scheduling to give (1) an exponential-time exact algorithm and
(2) a polynomial-time approximation scheme for computing an optimal MmS
allocation when the number of agents is fixed.


title:
Spectrally negative L\'evy processes with Parisian reflection below and
  classical reflection above

abstract:
  We consider a company that receives capital injections so as to avoid ruin.
Differently from the classical bail-out settings where the underlying process
is restricted to stay at or above zero, we study the case bail-out can only be
made at independent Poisson times. Namely, we study a version of the reflected
process that is pushed up to zero only on Poisson observation times at which
the process is below zero. We also study the case with additional classical
reflection above so as to model a company that pays dividends according to a
barrier strategy. Focusing on the spectrally negative L\'evy case, we compute,
using the scale function, various fluctuation identities including capital
injections and dividends.


title:
Time-reversal-invariance-violating nucleon-nucleon potential in the
  1/N_c expansion

abstract:
  We apply the large-$N_c$ expansion to the time-reversal-invariance-violating
(TV) nucleon-nucleon potential. The operator structures contributing to
next-to-next-to-leading order in the large-$N_c$ counting are constructed. For
the TV and parity-violating case we find a single operator structure at leading
order. The TV but parity-conserving potential contains two leading-order terms,
which however are suppressed by 1/$N_c$ compared to the parity-violating
potential. Comparison with phenomenological potentials, including the chiral
EFT potential in the TV parity-violating case, leads to large-$N_c$ scaling
relations for TV meson-nucleon and nucleon-nucleon couplings.


title:
Inclusive production of X$\rightarrow b\bar{b}$ plus a recoil for the
  LHC Run-II

abstract:
  This letter presents a study of the inclusive production of X$\rightarrow
b\bar{b}$ plus a recoil, using simulated samples of $pp$ collisions at
$\sqrt{s}=14$ TeV for an integrated luminosity in the range between 30
fb$^{-1}$ to 3 ab$^{-1}$. The case for experiments to include un-prescaled
$b$-tag multijet triggers for this topology is made and the ideal jet
thresholds are discussed. The sensitivity to Standard Model Higgs with a
transverse momentum of at least 200 GeV is evaluated with respect to a
continuous background, dominated by multijet processes. The mass of
$b$-jet-pairs is analysed, quoting sensitivity to cross-sections in the range
of 1 to 2 pb, for 100 fb$^{-1}$, covering the Higgs production cross section of
1.8 pb. The trigger strategy presented in this letter is compared to triggers
already in use, showing an increase on the signal efficiency for masses below
200 GeV and a performance comparable to a logic OR of all the currently
available akin triggers for higher masses. The robustness of the expected
sensitivity against systematic uncertainties is estimated by considering
various typical sources, such as those on the fitting parameters of the
continuous background, shape uncertainties affecting the signal acceptance and
the background modelling. The accuracy of a Higgs production cross section
measurements is also discussed, quoting sensitivity to deviations of 50% for
100 fb$^{-1}$ and 10% for 3 ab$^{-1}$.


title: Electro-osmosis in nematic liquid crystals

abstract:
  We derive a mathematical model of a nematic electrolyte based on a
variational formulation of nematodynamics. Extending our previous work, we
consider a general setup which incorporates dielectric anisotropy of the
liquid-crystalline matrix and the full set of nematic viscosities. We verify
the model by comparing its predictions to the results of the experiments on the
substrate-controlled liquid-crystal-enabled electrokinetics. In the experiments
a nematic liquid crystal confined to a thin planar cell with surface-patterned
anchoring conditions exhibit electro-osmotic flows along the "guiding rails"
imposed by the spatially varying director.


title: Effective models of inflation from a non-local framework

abstract:
  The dilaton is a possible inflaton candidate following recent CMB data
allowing a non-minimal coupling to the Ricci curvature scalar in the early
Universe. In this paper, we introduce an approach that has seldom been used in
the literature, namely dilaton inflation with non-local features. More
concretely, employing non-local features expressed in J. High Energy Phys. 04
(2007) 029, we study quadratic variations around a de Sitter geometry of an
effective action with a non-local dilaton. The non-locality refers to an
infinite derivative kinetic term involving the operator
$\mathcal{F}\left(\Box\right)$. Algebraic roots of the characteristic equation
$\mathcal{F}(z)=0$ play a crucial role in determining the properties of the
theory. We subsequently study the cases when $\mathcal{F}\left(\Box\right)$ has
one real root and one complex root, from which we retrieve two concrete
effective models of inflation. In the first case we retrieve a class of single
field inflations with universal prediction of $n_{s}\sim0.967$ with any value
of the tensor to scalar ratio $r<0.1$ intrinsically controlled by the root of
the characteristic equation. The second case involves a new class of two field
conformally invariant models with a peculiar quadratic cross-product of scalar
fields. In this latter case, we obtain Starobinsky like inflation through a
spontaneously broken conformal invariance. Furthermore, an uplifted minimum of
the potential, which accounts for the vacuum energy after inflation is produced
naturally through this mechanism intrinsically within our approach.


title: Evolving images of the proton: Hadron physics over the past 40 years

abstract:
  Once upon a time, the world was simple: the proton contained three quarks,
two {\it ups} and a {\it down}. How these give the proton its mass and its spin
seemed obvious. Over the past forty years the proton has become more
complicated, and how even these most obvious of its properties is explained in
a universe of quarks, antiquarks and gluons remains a challenge. That this
should be so should come as no surprise. Quantum Chromodynamics, the theory of
the strong interaction, is seemingly simple, and its consequences are
straightforward in the domain of hard scattering where perturbation theory
applies. However, the beauty of the hadron world is its diversity. The
existence of hadrons, their properties, and their binding into nuclei do not
appear in the Lagrangian of QCD. They all emerge as a result of its strong
coupling. Strong coupling QCD creates complex phenomena, much richer than known
40 years ago: a richness that ensures colour confinement and accounts for more
than 95\% of the mass of the visible Universe. How strong coupling QCD really
works requires a synergy between experiment and theory. A very personal view of
these fascinating developments in cold QCD is presented.


title: Constraints on Steep Equation of State for the Dark Energy using BAO

abstract:
  We present a parametrization for the Dark Energy Equation of State "EoS"
which has a rich structure. Our EoS has a transition at pivotal redshift $z_T$
between the present day value $w_0$ to an early time $w_i=w_a+w_0\equiv
w(z>>0)$ and the steepness of this transition is given in terms of the $q$
parameter. The proposed parametrization is $w=w_0+w_a(z/z_T)^q/(1+(z/z_T))^q$,
with $w_0$, $w_i$, $q $ and $z_T$ constant parameters. This transition is
motivated by scalar field dynamics such as for example quintessence models. Our
parametrization reduces to the widely used EoS $w=w_0+w_a(1-a)$ for $z_T=q=1$.
We study if a late time transition is favored by BAO measurements and Planck
priors. According to our results, an EoS with a present value of $w_0 = -0.91$
and a high redshifts value $w_i =-0.62$, featuring a transition at a redshift
of $z_T = 1.16$ with an exponent $q = 9.95$ is a good fit to the observational
data. We found good agreement between the model and the data reported by the
different surveys. A "thawing" dynamics is preferred by the use of BAO data
alone (including Lymman-$\alpha$ forest measurements) and a "freezing"
evolution of the EoS is preferred when we include the priors from Planck. The
constraints imposed by the available BAO measurements (\cite{Beutler:2011hx,
Ross:2014qpa, Anderson:2013oza, Kazin:2014qga, Font-Ribera:2013wce,
Delubac:2014aqe, Gong:2015tta}) and its physical behavior are discussed.


title:
Analysis of distributional variation through multi-scale Beta-Binomial
  modeling

abstract:
  Many statistical analyses involve the comparison of multiple data sets
collected under different conditions in order to identify the difference in the
underlying distributions. A common challenge in multi-sample comparison is the
presence of various confounders, or extraneous causes other than the conditions
of interest that also contribute to the difference across the distributions.
They result in false findings, i.e., identified differences that are not
replicable in follow-up investigations. We consider an ANOVA approach to
addressing this issue in multi-sample comparison---by collecting replicate data
sets under each condition, thereby allowing the identification of the
interesting distributional variation from the extraneous ones. We introduce a
multi-scale Bayesian hierarchical model for the analysis of distributional
variation (ANDOVA) under this design, based on a collection of Beta-Binomial
tests targeting variations of different scales at different locations across
the sample space. Instead treating the tests independently, the model employs a
graphical structure to introduce dependency among the individual tests thereby
allowing borrowing of strength among them. We derive efficient inference recipe
through a combination of numerical integration and message passing, and
evaluate the ability of our method to effectively address ANDOVA through
extensive simulation. We utilize our method to analyze a DNase-seq data set for
identifying differences in transcriptional factor binding.


title: A Convolutional Neural Network Neutrino Event Classifier

abstract:
  Convolutional neural networks (CNNs) have been widely applied in the computer
vision community to solve complex problems in image recognition and analysis.
We describe an application of the CNN technology to the problem of identifying
particle interactions in sampling calorimeters used commonly in high energy
physics and high energy neutrino physics in particular. Following a discussion
of the core concepts of CNNs and recent innovations in CNN architectures
related to the field of deep learning, we outline a specific application to the
NOvA neutrino detector. This algorithm, CVN (Convolutional Visual Network)
identifies neutrino interactions based on their topology without the need for
detailed reconstruction and outperforms algorithms currently in use by the NOvA
collaboration.


title:
An Axiomatic and an Average-Case Analysis of Algorithms and Heuristics
  for Metric Properties of Graphs

abstract:
  In recent years, researchers proposed several algorithms that compute metric
quantities of real-world complex networks, and that are very efficient in
practice, although there is no worst-case guarantee.
  In this work, we propose an axiomatic framework to analyze the performances
of these algorithms, by proving that they are efficient on the class of graphs
satisfying certain axioms. Furthermore, we prove that the axioms are verified
asymptotically almost surely by several probabilistic models that generate
power law random graphs, such as the In recent years, researchers proposed
several algorithms that compute metric quantities of real-world complex
networks, and that are very efficient in practice, although there is no
worst-case guarantee.
  In this work, we propose an axiomatic framework to analyze the performances
of these algorithms, by proving that they are efficient on the class of graphs
satisfying certain properties. Furthermore, we prove that these properties are
verified asymptotically almost surely by several probabilistic models that
generate power law random graphs, such as the Configuration Model, the Chung-Lu
model, and the Norros-Reittu model. Thus, our results imply average-case
analyses in these models.
  For example, in our framework, existing algorithms can compute the diameter
and the radius of a graph in subquadratic time, and sometimes even in time
$n^{1+o(1)}$. Moreover, in some regimes, it is possible to compute the $k$ most
central vertices according to closeness centrality in subquadratic time, and to
design a distance oracle with sublinear query time and subquadratic space
occupancy.
  In the worst case, it is impossible to obtain comparable results for any of
these problems, unless widely-believed conjectures are false.


title: Quantifying Distributional Model Risk via Optimal Transport

abstract:
  This paper deals with the problem of quantifying the impact of model
misspecification when computing general expected values of interest. The
methodology that we propose is applicable in great generality, in particular,
we provide examples involving path dependent expectations of stochastic
processes. Our approach consists in computing bounds for the expectation of
interest regardless of the probability measure used, as long as the measure
lies within a prescribed tolerance measured in terms of a flexible class of
distances from a suitable baseline model. These distances, based on optimal
transportation between probability measures, include Wasserstein's distances as
particular cases. The proposed methodology is well-suited for risk analysis, as
we demonstrate with a number of applications. We also discuss how to estimate
the tolerance region non-parametrically using Skorokhod-type embeddings in some
of these applications.


title: Relativistic Quantum Finance

abstract:
  Employing the Klein-Gordon equation, we propose a generalized Black-Scholes
equation. In addition, we found a limit where this generalized equation is
invariant under conformal transformations, in particular invariant under scale
transformations. In this limit, we show that the stock prices distribution is
given by a Cauchy distribution, instead of a normal distribution.


title:
Traveling wave solutions for bistable fractional Allen-Cahn equations
  with a pyramidal front

abstract:
  Using the method of sub-super-solution, we construct a solution of
$(-\Delta)^su-cu_z-f(u)=0$ on $\R^3$ of pyramidal shape. Here $(-\Delta)^s$ is
the fractional Laplacian of sub-critical order $1/2<s<1$ and $f$ is a bistable
nonlinearity. Hence, the existence of a traveling wave solution for the
parabolic fractional Allen-Cahn equation with pyramidal front is asserted.
  The maximum of planar traveling wave solutions in various directions gives a
sub-solution. A super-solution is roughly defined as the one-dimensional
profile composed with the signed distance to a rescaled mollified pyramid. In
the main estimate we use an expansion of the fractional Laplacian in the Fermi
coordinates.


title: Convolution of Picard-Fuchs equations

abstract:
  We determine explicit generators for a cohomology group constructed from a
solution of a fuchsian linear differential equation and describe its relation
with cohomology groups with coefficients in a local system. In the
parameterized case, this yields into an algorithm which computes new fuchsian
differential equations from those depending on multi-parameters. This
generalizes the classical convolution of solutions of fuchsian differential
equations.


title: Does Technical Debt Lead to the Rejection of Pull Requests?

abstract:
  Technical Debt is a term used to classify non-optimal solutions during
software development. These solutions cause several maintenance problems and
hence they should be avoided or at least documented. Although there are a
considered number of studies that focus on the identification of Technical
Debt, we focus on the identification of Technical Debt in pull requests.
Specifically, we conduct an investigation to reveal the different types of
Technical Debt that can lead to the rejection of pull requests. From the
analysis of 1,722 pull requests, we classify Technical Debt in seven categories
namely design, documentation, test, build, project convention, performance, or
security debt. Our results indicate that the most common category of Technical
Debt is design with 39.34%, followed by test with 23.70% and project convention
with 15.64%. We also note that the type of Technical Debt influences on the
size of push request discussions, e.g., security and project convention debts
instigate more discussion than the other types.


title: A new multigroup method for cross-sections that vary rapidly in energy

abstract:
  We present a numerical method for solving the time-independent thermal
radiative transfer (TRT) equation or the neutron transport (NT) equation when
the opacity or cross-section varies rapidly in energy (frequency). The approach
is based on a rigorous homogenization of the TRT/NT equation in the energy
(frequency) variable. Discretization of the homogenized TRT/NT equation results
in a multigroup-type system, and can therefore be solved by standard methods.
  We demonstrate the accuracy and efficiency of the approach on three model
problems. First we consider the Elsasser band model with constant temperature
and a small line spacing. Second, we consider a neutron transport application
for fast neutrons incident on iron, where the characteristic resonance spacing
necessitates about 16,000 energy discretization parameters if Planck-weighted
cross sections are used. Third, we consider an atmospheric TRT problem with an
opacity corresponding to water vapor. For all three problems, we demonstrate
that we can achieve between 0.1 and 1 percent relative error in the solution,
and with several orders of magnitude fewer parameters than a standard
multigroup formulation with a comparable accuracy.


title:
The Probabilistic Analysis of the Communication Network created by
  Dynamic Boundary Coverage

abstract:
  We do a Probabilistic Analysis of the Network generated by robots involved in
Stochastic Boundary Coverage


title: Monopole transitions to cluster states in $^{10}$Be and $^9$Li

abstract:
  Isoscalar monopole transitions from the ground states to cluster states in
$\Be$ and $\Li$ are investigated with $\He+\alpha$ and $\He+t$ cluster models,
respectively. In $\Be$, significant monopole strengths to $\He+\alpha$ cluster
resonances of $\Be(0^+_{3,4})$ above the $\alpha$-decay threshold are obtained,
whereas those to $\He+t$ cluster resonances in $^9$Li are not enhanced because
of the large fragmentation of the strengths in the corresponding energy region.
The monopole transition to $\Be(0^+_2)$ having the molecular orbital structure
is relatively weak compared with those to $\He+\alpha$ cluster resonances.
  Monopole strength distributions do not directly correspond to distributions
of $\He(0^+)+\alpha$ and $\He(0+)+t$ components but they reflect component of
the deformed $\He$ cluster with a specific orientation, which is originally
embedded in the ground state.


title: Using Hermite Function for Solving Thomas-Fermi Equation

abstract:
  In this paper, we propose Hermite collocation method for solving Thomas-Fermi
equation that is nonlinear ordinary differential equation on semi-infinite
interval. This method reduces the solution of this problem to the solution of a
system of algebraic equations. We also present the comparison of this work with
solution of other methods that shows the present solution is more accurate and
faster convergence in this problem.


title: Picking Winners in Daily Fantasy Sports Using Integer Programming

abstract:
  We consider the problem of selecting a portfolio of entries of fixed
cardinality for contests with top-heavy payoff structures, i.e. most of the
winnings go to the top-ranked entries. This framework is general and can be
used to model a variety of problems, such as movie studios selecting movies to
produce, venture capital firms picking start-up companies to invest in, or
individuals selecting lineups for daily fantasy sports contests, which is the
example we focus on here. We model the portfolio selection task as a
combinatorial optimization problem with a submodular objective function, which
is given by the probability of at least one entry winning. We then show that
this probability can be approximated using only pairwise marginal probabilities
of the entries winning when there is a certain structure on their joint
distribution. We consider a model where the entries are jointly Gaussian random
variables and present a closed form approximation to the objective function.
Building on this, we then consider a scenario where the entries are given by
sums of constrained resources and present an integer programming formulation to
construct the entries. Our formulation uses principles based on our theoretical
analysis to construct entries: we maximize the expected score of an entry
subject to a lower bound on its variance and an upper bound on its correlation
with previously constructed entries. To demonstrate the effectiveness of our
integer programming approach, we apply it to daily fantasy sports contests that
have top-heavy payoff structures. We find that our approach performs well in
practice. Using our integer programming approach, we are able to rank in the
top-ten multiple times in hockey and baseball contests with thousands of
competing entries. Our approach can easily be extended to other problems with
constrained resources and a top-heavy payoff structure.


title:
Distributed State Machine Supervision for Long-baseline
  Gravitational-wave Detectors

abstract:
  The Laser Interferometer Gravitational-wave Observatory (LIGO) consists of
two identical yet independent, widely-separated, long-baseline
gravitational-wave detectors. Each Advanced LIGO detector consists of complex
optical-mechanical systems isolated from the ground by multiple layers of
active seismic isolation, all controlled by hundreds of fast, digital, feedback
control systems. This article describes a novel state machine-based automation
platform developed to handle the automation and supervisory control challenges
of these detectors. The platform, called \textit{Guardian}, consists of
distributed, independent, state machine automaton nodes organized
hierarchically for full detector control. User code is written in standard
Python and the platform is designed to facilitate the fast-paced development
process associated with commissioning the complicated Advanced LIGO
instruments. While developed specifically for the Advanced LIGO detectors,
Guardian is a generic state machine automation platform that is useful for
experimental control at all levels, from simple table-top setups to large-scale
multi-million dollar facilities.


title:
Stereoscopic Observation of Slipping Reconnection in A Double
  Candle-Flame-Shaped Solar Flare

abstract:
  The 2011 January 28 M1.4 flare exhibits two side-by-side candle-flame-shaped
flare loop systems underneath a larger cusp-shaped structure during the decay
phase, as observed at the northwestern solar limb by the Solar Dynamics
Observatory (SDO). The northern loop system brightens following the initiation
of the flare within the southern loop system, but all three cusp-shaped
structures are characterized by ~ 10 MK temperatures, hotter than the
arch-shaped loops underneath. The "Ahead" satellite of the Solar Terrestrial
Relations Observatory (STEREO) provides a top view, in which the post-flare
loops brighten sequentially, with one end fixed while the other apparently
slipping eastward. By performing stereoscopic reconstruction of the post-flare
loops in EUV and mapping out magnetic connectivities, we found that the
footpoints of the post-flare loops are slipping along the footprint of a
hyperbolic flux tube (HFT) separating the two loop systems, and that the
reconstructed loops share similarity with the magnetic field lines that are
traced starting from the same HFT footprint, where the field lines are
relatively flexible. These results argue strongly in favor of slipping magnetic
reconnection at the HFT. The slipping reconnection was likely triggered by the
flare and manifested as propagative dimmings before the loop slippage is
observed. It may contribute to the late-phase peak in Fe XVI 33.5 nm, which is
even higher than its main-phase counterpart, and may also play a role in the
density and temperature asymmetry observed in the northern loop system through
heat conduction.


title: Supernova Remnants In The Magellanic Clouds

abstract:
  We present initial results of an ongoing study of the supernova remnants
(SNRs) and candidates in the Magellanic Clouds. Some 108 objects in both Clouds
are considered to be either an SNR or a reliable candidate. This represents the
most complete sample of known SNRs in any galaxy. therefore, this study allows
us to study SNR population properties such as the size and spectral index
distribution. Here, we also show 12 known Large Magellanic Cloud SNRs from type
Ia SN explosions and briefly comment on their importance.


title:
Emergent quasi-one-dimensionality in a kagom\'e magnet: A simple route
  to complexity

abstract:
  We study the ground state phase diagram of the quantum spin-$1/2$ Heisenberg
model on the kagom\'{e} lattice with first- ($J_1 < 0$), second- ($J_2 < 0$),
and third-neighbor interactions ($J_d > 0$) by means of analytical low-energy
field theory and numerical density-matrix renormalization group (DMRG) studies.
The results offer a consistent picture of the $J_d$-dominant regime in terms of
three sets of spin chains weakly coupled by the ferromagnetic inter-chain
interactions $J_{1,2}$. When either $J_1$ or $J_2$ is dominant, the model is
found to support one of two cuboctohedral phases, cuboc1 and cuboc2. These
cuboc states host non-coplanar long-ranged magnetic order and possess finite
scalar spin chirality. However, in the compensated regime $J_1 \simeq J_2$, a
valence bond crystal phase emerges between the two cuboc phases. We find
excellent agreement between an analytical theory based on coupled spin chains
and unbiased DMRG calculations, including at a very detailed level of
comparison of the structure of the valence bond crystal state. To our
knowledge, this is the first such comprehensive understanding of a highly
frustrated two-dimensional (2d) quantum antiferromagnet. We find no evidence of
either the one-dimensional (1d) gapless spin liquid or the chiral spin liquids,
which were previously suggested by parton mean field theories.


title:
Pressure-Tuned Exchange Coupling of a Quantum Spin Liquid in the
  Molecular Triangular Lattice $\kappa$-(ET)$_2$Ag$_2$(CN)$_3$

abstract:
  The effects of pressure on a quantum spin liquid are investigated in an
organic Mott insulator $\kappa$-(ET)$_2$Ag$_2$(CN)$_3$ with a spin-1/2
triangular lattice. The application of negative chemical pressure to
$\kappa$-(ET)$_2$Cu$_2$(CN)$_3$, which is a well-known sister Mott insulator,
allows for extensive tuning of antiferromagnetic exchange coupling, with
$J/k_{\rm B} = 175 - 310$ K, under hydrostatic pressure. Based on $^{13}$C
nuclear magnetic resonance measurements under pressure, we uncover universal
scaling in the static and dynamic spin susceptibilities down to low
temperatures $\sim 0.1k_{\rm B}T/J$. The persistent fluctuations and residual
specific heat coefficient are consistent with the presence of gapless low-lying
excitations. Our results thus demonstrate fundamental finite-temperature
properties of quantum spin liquid in a wide parameter range.


title: The strong Bishop-Phelps-Bollob\'as property

abstract:
  In this paper we introduce the strong Bishop-Phelps-Bollob\'as property
(sBPBp) for bounded linear operators between two Banach spaces $X$ and $Y$.
This property is motivated by a Kim-Lee result which states, under our
notation, that a Banach space $X$ is uniformly convex if and only if the pair
$(X,\mathbb{K})$ satisfies the sBPBp. Positive results of pairs of Banach
spaces $(X,Y)$ satisfying this property are given and concrete pairs of Banach
spaces $(X, Y)$ failing it are exhibited. A complete characterization of the
sBPBp for the pairs $(\ell_p, \ell_q)$ is also provided.


title: Multidimensional lower density versions of Pl\"unnecke's inequality

abstract:
  We investigate the lower asymptotic density of sumsets in $\mathbb{N}^2$ by
proving certain Pl\"unnecke type inequalities for various notions of lower
density in $\mathbb{N}^2$. More specifically, we introduce a notion of lower
tableaux density in $\mathbb{N}^2$ which involves averaging over convex
tableaux-shaped regions in $\mathbb{N}^2$ which contain the origin. This
generalizes the well known Pl\"unnecke type inequality for the lower asymptotic
density of sumsets in $\mathbb{N}$. We also provide a conjectural Pl\"unnecke
inequality for the more basic notion of lower rectangular asymtpotic density in
$\mathbb{N}^2$ and prove certain partial results.


title: Sussing Merger Trees: Stability and Convergence

abstract:
  Merger trees are routinely used to follow the growth and merging history of
dark matter haloes and subhaloes in simulations of cosmic structure formation.
Srisawat et al. (2013) compared a wide range of merger-tree-building codes.
Here we test the influence of output strategies and mass resolution on
tree-building. We find that, somewhat surprisingly, building the tree from more
snapshots does not generally produce more complete trees; instead, it tends to
short- en them. Significant improvements are seen for patching schemes which
attempt to bridge over occasional dropouts in the underlying halo catalogues or
schemes which combine the halo-finding and tree-building steps seamlessly. The
adopted output strategy does not affec- t the average number of branches
(bushiness) of the resultant merger trees. However, mass resolution has an
influence on both main branch length and the bushiness. As the resolution
increases, a halo with the same mass can be traced back further in time and
will encounter more small progenitors during its evolutionary history. Given
these results, we recommend that, for simulations intended as precursors for
galaxy formation models where of order 100 or more snapshots are analysed, the
tree-building routine should be integrated with the halo finder, or at the very
least be able to patch over multiple adjacent snapshots.


title:
Feedback Bits Allocation for Interference Minimization in Cognitive
  Radio Communications

abstract:
  This letter studies the limited feedback cognitive radio system, where the
primary users (PU) are interfered by the secondary transmitter (ST) due to the
imperfect beamforming. We propose to allocate the feedback bits among multiple
PUs to minimize the maximum interference caused by the ST, by exploiting the
heterogeneous average channel gains. In addition, we study the problem of
minimizing the total feedback bits under a predefined interference threshold at
the PUs. The solutions with low complexity are proposed for the studied
problems, and the performances of bit allocations are analyzed. Simulation
results validate our analysis and demonstrate that the proposed solutions work
very well in terms of minimizing the maximum interference caused by the ST and
minimizing the total feedback bits under predefined interference threshold at
the PUs for limited feedback CR system.


title: Symmetry of Solutions for a Fractional System

abstract:
  We consider the following equations: \begin{equation*}
\left\{\begin{array}{ll} (-\triangle)^{\alpha/2}u(x)=f(v(x)), \\
(-\triangle)^{\beta/2}v(x)=g(u(x)), &x \in R^{n},\\ u,v\geq 0, &x \in R^{n},
\end{array} \right. \end{equation*} for continuous $f, g$ and $\alpha, \beta
\in (0,2)$. Under some natural assumptions on $f$ and $g$, by applying the
\emph{method of moving planes} directly to the system, we obtain symmetry on
non-negative solutions without any decay assumption on the solutions at
infinity.


title: Spectra of semi-infinite quantum graph tubes

abstract:
  The spectrum of a semi-infinite quantum graph tube with square period cells
is analyzed. The structure is obtained by rolling up a doubly periodic quantum
graph into a tube along a period vector and then retaining only a semi-infinite
half of the tube. The eigenfunctions associated to the spectrum of the
half-tube involve all Floquet modes of the full tube. This requires solving the
complex dispersion relation $D(\lambda,k_1,k_2)=0$ with
$(k_1,k_2)\in(\mathbb{C}/2\pi\mathbb{Z})^2$ subject to the constraint $\alpha
k_1 + \beta k_2 \equiv 0$ (mod $2\pi$), where $\alpha$ and $\beta$ are
integers. The number of Floquet modes for a given $\lambda\in\mathbb{R}$ is
$2\max\left\{ \alpha, \beta \right\}$. Rightward and leftward modes are
determined according to an indefinite energy flux form. The spectrum may
contain eigenvalues that depend on the boundary conditions, and some
eigenvalues may be embedded in the continuous spectrum.


title:
Infrared spectral energy distribution decomposition of WISE-selected,
  hyperluminous hot dust-obscured galaxies

abstract:
  We utilize a Bayesian approach to fit the observed mid-IR-to-submm/mm
spectral energy distributions (SEDs) of 22 WISE-selected and submm-detected,
hyperluminous hot dust-obscured galaxies. By adopting the Torus+GB model, we
decompose the observed IR SEDs of Hot DOGs into torus and cold dust components.
The main results are: 1) Hot DOGs in our submm-detected sample are
hyperluminous, with torus emission dominating the IR energy output. However,
cold dust emission is non-negligible, averagely contributing ~24% of total IR
luminosity. 2) Compared to QSO and starburst SED templates, the median SED of
Hot DOGs shows the highest luminosity ratio between mid-IR and submm at
rest-frame, while it is very similar to that of QSOs at 10-50um suggesting that
the heating sources of Hot DOGs should be buried AGNs. 3) Hot DOGs have both
high dust temperatures ~73K and IR luminosity of cold dust. The T-L relation of
Hot DOGs suggests that the increase in IR luminosity for Hot DOGs is mostly due
to the increase of the dust temperature, rather than dust mass. Hot DOGs have
lower dust masses than those of submillimeter galaxies (SMGs) and QSOs within
the similar redshift range. Both high IR luminosity of cold dust and relatively
low dust mass in Hot DOGs can be expected by their relatively high dust
temperatures. 4) Hot DOGs have high dust covering factors, which deviate the
previously proposed trend of the dust covering factor decreasing with
increasing bolometric luminosity. Finally, we can reproduce the observed
properties in Hot DOGs by employing a physical model of galaxy evolution. The
result suggests that Hot DOGs may lie at or close to peaks of both star
formation and black hole growth histories, and represent a transit phase during
the evolution of massive galaxies, transforming from the dusty starburst
dominated phase to the optically bright QSO phase. (abridged)


title:
Dualities for root systems with automorphisms and applications to
  non-split groups

abstract:
  This article establishes some elementary dualities for root systems with
automorphisms. We give several applications to reductive groups over
nonarchimedean local fields: (1) the proof of a conjecture of
Pappas-Rapoport-Smithling characterizing the extremal elements of the $\{ \mu
\}$-admissible sets attached to general non-split groups; (2) for quasi-split
groups, a simple uniform description of the Bruhat-Tits \'{e}chelonnage root
system $\Sigma_0$, the Knop root system $\widetilde{\Sigma}_0$, and the
Macdonald root system $\Sigma_1$, in terms of Galois actions on the absolute
roots $\Phi$; and (3) for quasi-split groups, the construction of the geometric
basis of the center of a parahoric Hecke algebra, and the expression of certain
important elements of the stable Bernstein center in terms of this basis.


title: A Stochastic Analysis of Network MIMO Systems

abstract:
  This paper quantifies the benefits and limitations of cooperative
communications by providing a statistical analysis of the downlink in network
multiple-input multiple-output (MIMO) systems. We consider an idealized model
where the multiple-antenna base-stations (BSs) are distributed according to a
homogeneous Poisson point process and cooperate by forming disjoint clusters.
We assume that perfect channel state information (CSI) is available at the
cooperating BSs without any overhead. Multiple single-antenna users are served
using zero-forcing beamforming with equal power allocation across the beams.
For such a system, we obtain tractable, but accurate, approximations of the
signal power and inter-cluster interference power distributions and derive a
computationally efficient expression for the achievable per-BS ergodic sum rate
using tools from stochastic geometry. This expression allows us to obtain the
optimal loading factor, i.e., the ratio between the number of scheduled users
and the number of BS antennas, that maximizes the per-BS ergodic sum rate.
Further, it allows us to quantify the performance improvement of network MIMO
systems as a function of the cooperating cluster size. We show that to perform
zero-forcing across the distributed set of BSs within the cluster, the network
MIMO system introduces a penalty in received signal power. Along with the
inevitable out-of-cluster interference, we show that the per-BS ergodic sum
rate of a network MIMO system does not approach that of an isolated cell even
at unrealistically large cluster sizes. Nevertheless, network MIMO does provide
significant rate improvement as compared to uncoordinated single-cell
processing even at relatively modest cluster sizes.


title:
The topological property of the irregular sets on the lengths of basic
  intervals in beta-expansions

abstract:
  Let $\beta > 1$ be a real number and $(\epsilon_1(x, \beta), \epsilon_2(x,
\beta), \ldots)$ be the $\beta$-expansion of a point $x \in (0, 1]$. For all $x
\in (0,1]$, let $A(D(x))$ be the set of accumulation points of
$\frac{-\log_\beta |I_n(x)|}{n}$ as $n \rightarrow \infty$, where $|I_n(x)|$ is
the length of the basic interval of order $n$ containing $x \in (0, 1]$. In
this paper, we prove that $A(D(x))$ is always a closed interval for any $x \in
(0,1]$. Furthermore, if $\lambda(\beta)>0$, the extremely irregular set
containing points $x \in [0, 1]$ whose upper limit of $\frac{-\log_\beta
|I_n(x)|}{n}$ equals to $1+\l(\beta)$ is residual, where $1+\l(\beta)$ is a
constant depending on $\beta$. As a consequence, the irregular set with $x\in
[0, 1]$ whose limit of $\frac{-\log_\beta |I_n(x)|}{n}$ does not exist is
residual for every $\lambda(\beta)>0$.


title:
Quantum probabilities from quantum entanglement: Experimentally
  unpacking the Born rule

abstract:
  The Born rule, a foundational axiom used to deduce probabilities of events
from wavefunctions, is indispensable in the everyday practice of quantum
physics. It is also key in the quest to reconcile the ostensibly inconsistent
laws of the quantum and classical realms, as it confers physical significance
to reduced density matrices, the essential tools of decoherence theory.
Following Bohr's Copenhagen interpretation, textbooks postulate the Born rule
outright. However, recent attempts to derive it from other quantum principles
have been successful, holding promise for simplifying and clarifying the
quantum foundational bedrock. A major family of derivations is based on
envariance, a recently discovered symmetry of entangled quantum states. Here,
we identify and experimentally test three premises central to these
envariance-based derivations, thus demonstrating, in the microworld, the
symmetries from which the Born rule is derived. Further, we demonstrate
envariance in a purely local quantum system, showing its independence from
relativistic causality.


title: Conjugate Processes: Theory and Application to Risk Forecasting

abstract:
  Many dynamical phenomena display a cyclic behavior, in the sense that time
can be partitioned into units within which distributional aspects of a process
are homogeneous. In this paper, we introduce a class of models - called
conjugate processes - allowing the sequence of marginal distributions of a
cyclic, continuous-time process to evolve stochastically in time. The
connection between the two processes is given by a fundamental compatibility
equation. Key results include Laws of Large Numbers in the presented framework.
We provide a constructive example which illustrates the theory, and give a
statistical implementation to risk forecasting in financial data.


title: Antiferromagnetic domain wall motion driven by spin-orbit torques

abstract:
  We theoretically investigate dynamics of antiferromagnetic domain walls
driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show
that spin-orbit torques drive antiferromagnetic domain walls much faster than
ferromagnetic domain walls. As the domain wall velocity approaches the maximum
spin-wave group velocity, the domain wall undergoes Lorentz contraction and
emits spin-waves in the terahertz frequency range. The interplay between spin
orbit torques and the relativistic dynamics of antiferromagnetic domain walls
leads to the efficient manipulation of antiferromagnetic spin textures and
paves the way for the generation of high frequency signals in antiferromagnets.


title: Self-Paced Multi-Task Learning

abstract:
  In this paper, we propose a novel multi-task learning (MTL) framework, called
Self-Paced Multi-Task Learning (SPMTL). Different from previous works treating
all tasks and instances equally when training, SPMTL attempts to jointly learn
the tasks by taking into consideration the complexities of both tasks and
instances. This is inspired by the cognitive process of human brain that often
learns from the easy to the hard. We construct a compact SPMTL formulation by
proposing a new task-oriented regularizer that can jointly prioritize the tasks
and the instances. Thus it can be interpreted as a self-paced learner for MTL.
A simple yet effective algorithm is designed for optimizing the proposed
objective function. An error bound for a simplified formulation is also
analyzed theoretically. Experimental results on toy and real-world datasets
demonstrate the effectiveness of the proposed approach, compared to the
state-of-the-art methods.


title: Learning A Deep $\ell_\infty$ Encoder for Hashing

abstract:
  We investigate the $\ell_\infty$-constrained representation which
demonstrates robustness to quantization errors, utilizing the tool of deep
learning. Based on the Alternating Direction Method of Multipliers (ADMM), we
formulate the original convex minimization problem as a feed-forward neural
network, named \textit{Deep $\ell_\infty$ Encoder}, by introducing the novel
Bounded Linear Unit (BLU) neuron and modeling the Lagrange multipliers as
network biases. Such a structural prior acts as an effective network
regularization, and facilitates the model initialization. We then investigate
the effective use of the proposed model in the application of hashing, by
coupling the proposed encoders under a supervised pairwise loss, to develop a
\textit{Deep Siamese $\ell_\infty$ Network}, which can be optimized from end to
end. Extensive experiments demonstrate the impressive performances of the
proposed model. We also provide an in-depth analysis of its behaviors against
the competitors.


title:
Zadoff-Chu sequence design for random access initial uplink
  synchronization

abstract:
  The autocorrelation of a Zadoff-Chu (ZC) sequence with a non-zero cyclically
shifted version of itself is zero. Due to the interesting property, ZC
sequences are widely used in the LTE air interface in the primary
synchronization signal (PSS), random access preamble (PRACH), uplink control
channel (PUCCH) etc. However, this interesting property of ZC sequence is not
useful in the random access initial uplink synchronization problem due to some
specific structures of the underlying problem. In particular, the state of the
art uplink synchronization algorithms do not perform equally for all ZC
sequences. In this work, we show a systematic procedure to choose the ZC
sequences that yield the optimum performance of the uplink synchronization
algorithms. At first, we show that the uplink synchronization is a sparse
signal recovery problem on an overcomplete basis. Next, we use the theory of
sparse recovery algorithms and identify a factor that controls performance of
the algorithms. We then suggest a ZC sequence design procedure to optimally
choose this factor. The simulation results show that the performance of most of
the state of the art uplink synchronization algorithms improve significantly
when the ZC sequences are chosen by using the proposed technique.


title: On two cohomological Hall algebras

abstract:
  We compare two cohomological Hall algebras (CoHA). The first one is the
preprojective CoHA introduced by the authors in arXiv:1407.7994 associated to
each quiver Q, and each algebraic oriented cohomology theory A. It is defined
as the A-homology of the moduli of representations of the preprojective algebra
of Q, generalizing the K-theoretic Hall algebra of commuting varieties of
Schiffmann-Vasserot. The other one is the critical CoHA defined by
Kontsevich-Soibelman associated to each quiver with potentials. It is defined
using the equivariant cohomology with compact support with coefficients in the
sheaf of vanishing cycles. In the present paper, we show that the critical
CoHA, for the quiver with potential of Ginzburg, is isomorphic to the
preprojective CoHA as algebras. As applications, we obtain an algebra
homomorphism from the positive part of the Yangian to the critical CoHA.


title:
Higher order Whitehead products and $L_\infty$ structures on the
  homology of a DGL

abstract:
  We detect higher order Whitehead products on the homology $H$ of a
differential graded Lie algebra $L$ in terms of higher brackets in the
transferred $L_\infty$ structure on $H$ via a given homotopy retraction of $L$
onto $H$.


title: Phase separation and pair condensation in a spin-imbalanced 2D Fermi gas

abstract:
  We study a two-component quasi-two-dimensional Fermi gas with imbalanced spin
populations. We probe the gas at different interaction strengths and
polarizations by measuring the density of each spin component in the trap and
the pair momentum distribution after time of flight. For a wide range of
experimental parameters, we observe in-trap phase separation characterized by
the appearance of a spin-balanced condensate surrounded by a polarized gas. Our
momentum space measurements indicate pair condensation in the imbalanced gas
even for large polarizations where phase separation vanishes, pointing to the
presence of a polarized pair condensate. Our observation of zero momentum pair
condensates in 2D spin-imbalanced gases opens the way to explorations of more
exotic superfluid phases that occupy a large part of the phase diagram in lower
dimensions.