title: NOON States via Quantum Walk of Bound Particles

abstract:
  Tight-binding lattice models allow the creation of bound composite objects
which, in the strong-interacting regime, are protected against dissociation. We
show that a local impurity in the lattice potential can generate a coherent
split of an incoming bound particle wave-packet which consequently produces a
NOON state between the endpoints. This is non trivial because when finite
lattices are involved, edge-localisation effects make their use for
non-classical state generation and information transfer challenging. We derive
an effective model to describe the propagation of bound particles in a
Bose-Hubbard chain. We introduce local impurities in the lattice potential to
inhibit localisation effects and to split the propagating bound particle, thus
enabling the generation of distant NOON states. We analyse how minimal
engineering transfer schemes improve the transfer fidelity and we quantify the
robustness to typical decoherence effects in optical lattice implementations.
Our scheme potentially have an impact on quantum-enhanced atomic interferometry
in a lattice.


title:
Chiral anomaly from strain-induced gauge fields in Dirac and Weyl
  semimetals

abstract:
  Dirac and Weyl semimetals form an ideal platform for testing ideas developed
in high energy physics to describe massless relativistic particles. One such
quintessentially field-theoretic idea of chiral anomaly already resulted in the
prediction and subsequent observation of the pronounced negative
magnetoresistance in these novel materials for parallel electric and magnetic
fields. Here we predict that the chiral anomaly occurs - and has experimentally
observable consequences - when real electromagnetic fields E and B are replaced
by strain-induced pseudo-electromagnetic fields e and b. For example, a uniform
pseudomagnetic field b is generated when a Weyl semimetal nanowire is put under
torsion. In accord with the chiral anomaly equation we predict a negative
contribution to the wire resistance proportional to the square of the torsion
strength. Remarkably, left and right moving chiral modes are then spatially
segregated to the bulk and surface of the wire forming a "topological coaxial
cable". This produces hydrodynamic flow with potentially very long relaxation
time. Another effect we predict is the ultrasonic attenuation and
electromagnetic emission due to a time periodic mechanical deformation causing
pseudoelectric field e. These novel manifestations of the chiral anomaly are
most striking in the semimetals with a single pair of Weyl nodes but also occur
in Dirac semimetals such as Cd3As2 and Na3Bi and Weyl semimetals with unbroken
time reversal symmetry.


title: Double-difference adjoint seismic tomography

abstract:
  We introduce a `double-difference' method for the inversion for seismic
wavespeed structure based on adjoint tomography. Differences between seismic
observations and model predictions at individual stations may arise from
factors other than structural heterogeneity, such as errors in the assumed
source-time function, inaccurate timings, and systematic uncertainties. To
alleviate the corresponding nonuniqueness in the inverse problem, we construct
differential measurements between stations, thereby reducing the influence of
the source signature and systematic errors. We minimize the discrepancy between
observations and simulations in terms of the differential measurements made on
station pairs. We show how to implement the double-difference concept in
adjoint tomography, both theoretically and in practice. We compare the
sensitivities of absolute and differential measurements. The former provide
absolute information on structure along the ray paths between stations and
sources, whereas the latter explain relative (and thus higher-resolution)
structural variations in areas close to the stations. Whereas in conventional
tomography a measurement made on a single earthquake-station pair provides very
limited structural information, in double-difference tomography one earthquake
can actually resolve significant details of the structure. The
double-difference methodology can be incorporated into the usual adjoint
tomography workflow by simply pairing up all conventional measurements; the
computational cost of the necessary adjoint simulations is largely unaffected.
Rather than adding to the computational burden, the inversion of
double-difference measurements merely modifies the construction of the adjoint
sources for data assimilation.


abstract:
  Rogue waves in birefringent optical fibers are analyzed within the framework
of the coupled nonlinear Schr\"odinger (CNLS) system. The generation of rogue
waves is frequently associated with modulation instability (MI). It is commonly
expected that since the CNLS equations exhibit larger growth rates they should
also produce more rogue events than their scalar counterparts. This is found to
occur only when both equations are focusing. When at least one component is
defocusing, the CNLS equations may still exhibit larger growth rates, compared
to the scalar system, but that does not necessarily result in more or larger
events. The birefringence angle for which the maximum number of events occurs
is also identified and the nature of the rogue wave is described for the
different cases.


title: Derivation of homogenized Euler-Lagrange equations for von Karman rod

abstract:
  In this paper we study the effects of simultaneous homogenization and
dimension reduction in the context of convergence of stationary points for thin
nonhomogeneous rods under the assumption of the von K\'arm\'an scaling.
Assuming stationarity condition for a sequence of deformations close to a rigid
body motion, we prove that the corresponding sequences of scaled displacements
and twist functions converge to a limit point, which is the stationary point of
the homogenized von K\'arm\'an rod model. The analogous result holds true for
the von K\'arm\'an plate model.


title: Gowers norms of multiplicative functions in progressions on average

abstract:
  Let $\mu$ be the M\"{o}bius function and let $k \geq 1$. We prove that the
Gowers $U^k$-norm of $\mu$ restricted to progressions $\{n \leq X: n\equiv
a_q\pmod{q}\}$ is $o(1)$ on average over $q\leq X^{1/2-\sigma}$ for any $\sigma
> 0$, where $a_q\pmod{q}$ is an arbitrary residue class with $(a_q,q) = 1$.
This generalizes the Bombieri-Vinogradov inequality for $\mu$, which
corresponds to the special case $k=1$.


title:
A practical method in calculating one loop quantum fluctuations to the
  energy of the non-topological soliton

abstract:
  I have used a practical method to calculate the one-loop quantum correction
to the energy of the non-topological soliton in Friedberg-Lee model. The
quantum effects which come from the quarks of the Dirac sea scattering with the
soliton bag are calculated by a summation of the discrete and continuum energy
spectrum of the Dirac equation in the background field of soliton. The phase
shift of the continuum spectrum is numerically calculated in an efficient way
and all the divergences are removed by the same renormalization procedure.


title:
Broadband low-noise photodetector for Pound-Drever-Hall laser
  stabilization

abstract:
  The Pound-Drever-Hall laser stabilization technique requires a fast,
low-noise photodetector. We present a simple photodetector design that uses a
transformer as an intermediary between a photodiode and cascaded low-noise
radio-frequency amplifiers. Our implementation using a silicon photodiode
yields a detector with 50 MHz bandwidth, gain $> 10^5$ V/A, and input current
noise $< 4$ pA/$\sqrt{\mathrm{Hz}}$, allowing us to obtain shot-noise-limited
performance with low optical power.


title: A System of Dependent Types, with an Implementation and a Philosophy

abstract:
  This is my working paper on a proposed logical framework for the practice of
mathematics, which is paralleled by philosophical considerations and a computer
implementation (a variant of Automath). Updated 10/27/2016 with a version from
10/22/2016. New versions are regularly posted on the author's web page at
http://math.boisestate.edu/%7Eholmes/automath/ which is a directory containing
various related files.


title:
Asymptotic Comparison of ML and MAP Detectors for Multidimensional
  Constellations

abstract:
  A classical problem in digital communications is to evaluate the symbol error
probability (SEP) and bit error probability (BEP) of a multidimensional
constellation over an additive white Gaussian noise channel. In this paper, we
revisit this problem for nonequally likely symbols and study the asymptotic
behavior of the optimal maximum a posteriori (MAP) detector. Exact closed-form
asymptotic expressions for SEP and BEP for arbitrary constellations and input
distributions are presented. The well-known union bound is proven to be
asymptotically tight under general conditions. The performance of the
practically relevant maximum likelihood (ML) detector is also analyzed.
Although the decision regions with MAP detection converge to the ML regions at
high signal-to-noise ratios, the ratio between the MAP and ML detector in terms
of both SEP and BEP approach a constant, which depends on the constellation and
a priori probabilities. Necessary and sufficient conditions for asymptotic
equivalence between the MAP and ML detectors are also presented.


title: NMSSM Inflation and Domain Walls from a Tri-critical Point of View

abstract:
  We study the conditions in which we could bring a universe filled with
different $Z_3$ vacua created during the Next to Minimal Supersymmetric
Standard Model (NMSSM) electroweak symmetry breaking at $\textit{O} (10)^2$ GeV
and a three dimensional three states diluted Potts model together in the same
universality class. Then we use Cardy-Jacobsen conjecture to prove that there
might be a tri-critical point in the NMSSM electroweak epoch of early universe.
We prove that due to the existence of this point there would be no cosmological
domain wall problem. Moreover, at this point the heat capacity and correlation
length diverge which lead to a huge amount of energy release at constant
temperature and a new mechanism for cosmological structure formation. Also, the
entropy decrease after the tri-critical phase transition could explain the
problem of low initial entropy in early universe. Finally, we combine
Cardy-Jacobsen and Yaffe-Svetitsky conjectures to show that there might be a
tri-critical point for the $Z_3$ center symmetry breaking in a pure SU(3)
theory at $\textit{O} (10)^2$ MeV. Near the pure SU(3) tri-critical point,
unlike the electroweak epoch tri-critical point, entropy increases rather than
decrease.


title:
Plus Charge Prevalence in Cosmic Rays: Room for Dark Matter in the
  Positron Spectrum

abstract:
  The unexpected energy spectrum of the positron/electron ratio is interpreted
astrophysically, with a possible exception of the 100-300 GeV range. The data
indicate that this ratio, after a decline between $0.5-8$ GeV, rises steadily
with a trend towards saturation at 200-400GeV. These observations (except for
the trend) appear to be in conflict with the diffusive shock acceleration (DSA)
mechanism, operating in a \emph{single} supernova remnant (SNR) shock. We argue
that $e^{+}/e^{-}$ ratio can still be explained by the DSA if positrons are
accelerated in a \emph{subset} of SNR shocks which: (i) propagate in clumpy gas
media, and (ii) are modified by accelerated CR \emph{protons}. The protons
penetrate into the dense gas clumps upstream to produce positrons and,
\emph{charge the clumps positively}. The induced electric field expels
positrons into the upstream plasma where they are shock-accelerated. Since the
shock is modified, these positrons develop a harder spectrum than that of the
CR electrons accelerated in other SNRs. Mixing these populations explains the
increase in the $e^{+}/e^{-}$ ratio at $E>8$ GeV. It decreases at $E<8$ GeV
because of a subshock weakening which also results from the shock modification.
Contrary to the expelled positrons, most of the antiprotons, electrons, and
heavier nuclei, are left unaccelerated inside the clumps. Scenarios for the
100-300 GeV AMS-02 fraction exceeding the model prediction, including, but not
limited to, possible dark matter contribution, are also discussed.


title:
A Graph Theoretic Approach to the Robustness of k-Nearest Neighbor
  Vehicle Platoons

abstract:
  We consider a graph theoretic approach to the performance and robustness of a
platoon of vehicles, where each vehicle communicates with its $k$-nearest
neighbors. In particular, we quantify the platoon's stability margin,
robustness to disturbances (in terms of system $\mathcal{H}_{\infty}$ norm),
and maximum delay tolerance via graph-theoretic notions such as nodal degrees
and (grounded) Laplacian matrix eigenvalues. Our results show that there is a
trade-off between robustness to time delay and robustness to disturbances. Both
first-order dynamics (reference velocity tracking) and second-order dynamics
(controlling inter-vehicular distance) are analyzed in this direction.
Theoretical contributions are confirmed via simulation results.


title:
An Adaptive Multiresoluton Discontinuous Galerkin Method for
  Time-Dependent Transport Equations in Multi-dimensions

abstract:
  In this paper, we develop an adaptive multiresolution discontinuous Galerkin
(DG) scheme for time-dependent transport equations in multi-dimensions. The
method is constructed using multiwavlelets on tensorized nested grids.
Adaptivity is realized by error thresholding based on the hierarchical surplus,
and the Runge-Kutta DG (RKDG) scheme is employed as the reference time
evolution algorithm. We show that the scheme performs similarly to a sparse
grid DG method when the solution is smooth, reducing computational cost in
multi-dimensions. When the solution is no longer smooth, the adaptive algorithm
can automatically capture fine local structures. The method is therefore very
suitable for deterministic kinetic simulations. Numerical results including
several benchmark tests, the Vlasov-Poisson (VP) and oscillatory VP systems are
provided.


title: Noise-free quantum optical frequency shifting driven by mechanics

abstract:
  The ability to manipulate single photons is of critical importance for
fundamental quantum optics studies and practical implementations of quantum
communications. While extraordinary progresses have been made in controlling
spatial, temporal, spin and orbit angular momentum degrees of freedom,
frequency-domain control of single photons so far relies on nonlinear optical
effects, which have faced obstacles such as noise photons, narrow bandwidth and
demanding optical filtering. Here we demonstrate the first integrated
near-unity efficiency frequency manipulation of single photons, by stretching
and compressing a waveguide at 8.3 billion cycles per second. Frequency shift
up to 150 GHz at telecom wavelength is realized without measurable added noise
and the preservation of quantum coherence is verified through quantum
interference between twin photons of different colors. This single photon
frequency control approach will be invaluable for increasing the channel
capacity of quantum communications and compensating frequency mismatch between
quantum systems, paving the road toward hybrid quantum network.


title: The infrared-dark dust content of high redshift galaxies

abstract:
  We present a theoretical model aimed at explaining the IRX-$\beta$ relation
for high redshift (z >5) galaxies. Recent observations (Capak+2015;
Bouwens+2016) have shown that early Lyman Break Galaxies, although
characterized by a large UV attenuation (e.g. flat UV beta slopes), show a
striking FIR deficit, i.e. they are "infrared-dark". This marked deviation from
the local IRX-beta relation can be explained by the larger molecular gas
content of these systems. While dust in the diffuse ISM attains relatively high
temperatures (Td = 45 K for typical size a=0.1 um; smaller grains can reach Td
= 60 K), a sizable fraction of the dust mass is embedded in dense gas, and
therefore remains cold. If confirmed, the FIR deficit might represent a novel,
powerful indicator of the molecular content of high-z galaxies which can be
used to pre-select candidates for follow-up deep CO observations. Thus, high-z
CO line searches with ALMA might be much more promising than currently thought.


title:
Optical modeling and polarization calibration for CMB measurements with
  ACTPol and Advanced ACTPol

abstract:
  The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization
sensitive upgrade to the Atacama Cosmology Telescope. Located at an elevation
of 5190 m, ACTPol measures the Cosmic Microwave Background (CMB) temperature
and polarization with arcminute-scale angular resolution. Calibration of the
detector angles is a critical step in producing maps of the CMB polarization.
Polarization angle offsets in the detector calibration can cause leakage in
polarization from E to B modes and induce a spurious signal in the EB and TB
cross correlations, which eliminates our ability to measure potential
cosmological sources of EB and TB signals, such as cosmic birefringence. We
present our optical modeling and measurements associated with calibrating the
detector angles in ACTPol.


title: Single-Player and Two-Player Buttons & Scissors Games

abstract:
  We study the computational complexity of the Buttons \& Scissors game and
obtain sharp thresholds with respect to several parameters. Specifically we
show that the game is NP-complete for $C = 2$ colors but polytime solvable for
$C = 1$. Similarly the game is NP-complete if every color is used by at most $F
= 4$ buttons but polytime solvable for $F \leq 3$. We also consider
restrictions on the board size, cut directions, and cut sizes. Finally, we
introduce several natural two-player versions of the game and show that they
are PSPACE-complete.


title:
Compressive Spectral Estimation with Single-Snapshot ESPRIT: Stability
  and Resolution

abstract:
  In this paper Estimation of Signal Parameters via Rotational Invariance
Techniques (ESPRIT) is developed for spectral estimation with single-snapshot
measurement. Stability and resolution analysis with performance guarantee for
Single-Snapshot ESPRIT (SS-ESPRIT) is the main focus. In the noise-free case,
exact reconstruction is guaranteed for any arbitrary set of frequencies as long
as the number of measurement data is at least twice the number of distinct
frequencies to be recovered. In the presence of noise and under the assumption
that the true frequencies are separated by at least two times Rayleigh's
Resolution Length, an explicit error bound for frequency reconstruction is
given in terms of the dynamic range and the separation of the frequencies. The
separation and sparsity constraint compares favorably with those of the leading
approaches to compressed sensing in the continuum.


title: A Note on Nested String Replacements

abstract:
  We investigate the number of nested string replacements required to reduce a
string of identical characters to one character.


title: The Hot Companion and Circumbinary Disk of the Be Star HR 2142

abstract:
  We present a spectroscopic investigation of the Be+sdO binary system HR 2142
that is based upon large sets of ultraviolet observations from the
International Ultraviolet Explorer and ground-based H-alpha observations. We
measured radial velocities for the Be star component from these spectra, and
computed a revised orbit. In order to search for the spectral signature of the
hot subdwarf, we cross-correlated the short wavelength end of each IUE spectrum
with a model hot star spectrum, and then we used the predicted Doppler shifts
of the subdwarf to shift-and-add all the cross-correlation functions to the
frame of the subdwarf. This merged function shows the weak signal from the
spectral lines of the hot star, and a best fit is obtained with a mass ratio
M_2/M_1 = 0.07 +/- 0.02, companion temperature T_{eff} > 43 +/- 5 kK, projected
rotational velocity V sin i < 30 km/s, and a monochromatic flux ratio near 1170
Angstroms of f_2/f_1 > 0.009 +/- 0.001. This hot subdwarf creates a one-armed
spiral, tidal wake in the disk of the Be star, and we present a circumbinary
disk model that can explain the occurrence of shell absorption lines by gas
enhancements that occur where gas crossing the gap created by the subdwarf
strikes the disk boundaries. The faint companion of HR 2142 may be
representative of a significant fraction of Be stars with undetected former
mass donor companion stars.


title: Hodge Numbers for All CICY Quotients

abstract:
  We present a general method for computing Hodge numbers for Calabi-Yau
manifolds realised as discrete quotients of complete intersections in products
of projective spaces. The method relies on the computation of equivariant
cohomologies and is illustrated for several explicit examples. In this way, we
compute the Hodge numbers for all discrete quotients obtained in Braun's
classification arXiv:1003.3235.


title: Physics at a 100 TeV pp collider: Standard Model processes

abstract:
  This report summarises the properties of Standard Model processes at the 100
TeV pp collider. We document the production rates and typical distributions for
a number of benchmark Standard Model processes, and discuss new dynamical
phenomena arising at the highest energies available at this collider. We
discuss the intrinsic physics interest in the measurement of these Standard
Model processes, as well as their role as backgrounds for New Physics searches.


title: On Contraction of Algebraic Points

abstract:
  We study contraction of points on $\mathbb{P}^1(\bar{\mathbb{Q}})$ with
certain control on local ramification indices, with application to the
unramified curve correspondences problem initiated by Bogomolov and Tschinkel.


title: Numerical algorithms on the affine Grassmannian

abstract:
  The affine Grassmannian is a noncompact smooth manifold that parameterizes
all affine subspaces of a fixed dimension. It is a natural generalization of
Euclidean space, points being zero-dimensional affine subspaces. We will
realize the affine Grassmannian as a matrix manifold and extend Riemannian
optimization algorithms including steepest descent, Newton method, and
conjugate gradient, to real-valued functions on the affine Grassmannian. Like
their counterparts for the Grassmannian, these algorithms are in the style of
Edelman--Arias--Smith --- they rely only on standard numerical linear algebra
and are readily computable.


title: Groups with at most twelve subgroups

abstract:
  We classify all of the groups with twelve or fewer subgroups. This paper is
the proof of the entries in a submission to the Online Encyclopedia of Integer
Sequences.


title:
Proceedings of the Fourth International Workshop on Verification and
  Program Transformation

abstract:
  This volume contains the revised versions of papers presented at the Fourth
International Workshop on Verification and Program Transformation (VPT 2016) on
April 2, 2016 in Eindhoven, The Netherlands. The workshop is an event of the
European Joint Conferences on Theory and Practice of Software (ETAPS 2016).
  The aim of the VPT workshops is to provide a forum where people from the area
of program transformation and the area of program verification can fruitfully
exchange ideas and gain a deeper understanding of the interactions between
those two fields. The research papers which have been recently published in
those fields, show that the interactions are very beneficial and, indeed, go
both ways. In one direction, methods and tools developed in the field of
program transformation, such as partial deduction, partial evaluation,
fold/unfold transformations, and supercompilation, have all been applied with
success for the verification of systems, and in particular, the verification of
infinite state and parameterized systems. In the other direction, methods
developed in program verification, such as model checking, abstract
interpretation, SAT and SMT solving, and automated theorem proving, have been
used to enhance program transformation techniques, thereby making these
techniques more powerful and useful in practice.


title:
Solvability of Hammerstein integral equations with applications to
  boundary value problems

abstract:
  In this paper we present some new results regarding the solvability of
nonlinear Hammerstein integral equations in a special cone of continuous
functions. The proofs are based on a certain fixed point theorem of Leggett and
Williams type. We give an application of the abstract result to prove the
existence of nontrivial solutions of a periodic boundary value problem. We also
investigate, via a version of Krasnosel{\cprime}slki{\u\i}'s theorem for the
sum of two operators, the solvability of perturbed Hammerstein integral
equations in the space of continuous functions of bounded variation in the
sense of Jordan. As an application of these results, we study the solvability
of a boundary value problem subject to integral boundary conditions of
Riemann--Stieltjes type. Some examples are presented in order to illustrate the
obtained results.


title: Using measurements of the cosmic bulk flow to constrain $f(R)$ Gravity

abstract:
  As an alternative explanation for the cosmic acceleration, $f(R)$ theories of
gravity can predict an almost identical expansion history to standard
$\Lambda$CDM, yet make very different predictions for the growth of
cosmological structures. Measurements of the cosmic bulk flow provides a method
for determining the strength of gravity over the history of structure
formation. We use the modified gravity N-body code ECOSMOG to simulate dark
matter particles and make predictions for the bulk flow magnitude in both
$\Lambda$CDM and $f(R)$ gravity. With the peculiar velocities output by ECOSMOG
we determine the bulk flow at depths ranging from $20h^{-1}$Mpc to
$50h^{-1}$Mpc, following the redshift and sky distribution of the 2MASS
Tully-Fisher survey (2MTF). At each depth, we find that the $\Lambda$CDM and
$f_{R0} = 10^{-5}$ simulations produce bulk flow measurements that are
consistent with $\Lambda$CDM predictions and the 2MTF survey at a $1\sigma$
level. We also find that adopting an $f(R)$ strength of $f_{R0} = 10^{-3}$
predict a much larger value for the bulk flow, which disagree with $\Lambda$CDM
predictions at all depths considered. We conclude that $f_{R0}$ must be
constrained to a level no greater than $10^{-4}$ to agree with bulk flow
measurements.


title: Coordinate-Descent Diffusion Learning by Networked Agents

abstract:
  This work examines the mean-square error performance of diffusion stochastic
algorithms under a generalized coordinate-descent scheme. In this setting, the
adaptation step by each agent is limited to a random subset of the coordinates
of its stochastic gradient vector. The selection of coordinates varies randomly
from iteration to iteration and from agent to agent across the network. Such
schemes are useful in reducing computational complexity at each iteration in
power-intensive large data applications. They are also useful in modeling
situations where some partial gradient information may be missing at random.
Interestingly, the results show that the steady-state performance of the
learning strategy is not always degraded, while the convergence rate suffers
some degradation. The results provide yet another indication of the resilience
and robustness of adaptive distributed strategies.


title: Asymptotic profiles of solutions for structural damped wave equations

abstract:
  In this paper, we obtain several asymptotic profiles of solutions to the
Cauchy problem for structurally damped wave equations $\partial_{t}^{2} u -
\Delta u + \nu (-\Delta)^{\sigma} \partial_{t} u=0$, where $\nu >0$ and $0<
\sigma \le1$. Our result is the approximation formula of the solution by a
constant multiple of a special function as $t \to \infty$, which states that
the asymptotic profiles of the solutions are classified into $5$ patterns
depending on the values $\nu$ and $\sigma$.


title:
Scaling in driven dynamics starting in the vicinity of a quantum
  critical point

abstract:
  We study the driven critical dynamics with an equilibrium initial state near
a quantum critical point. In contrast to the original Kibble-Zurek mechanism,
which describes the driven dynamics starting from an adiabatic stage that is
far from the critical point, the initial adiabacity is broken in this scenario.
As a result, the scaling behavior cannot be described by the original
Kibble-Zurek scaling. In this work we propose a scaling theory, which includes
the initial parameters as additional scaling variables, to characterize the
scaling behavior. In particular, this scaling theory can be used to describe
the driven scaling behavior starting from a finite-temperature equilibrium
state near a quantum critical point. We numerically confirm the scaling theory
by simulating the real-time dynamics of the one-dimensional quantum Ising model
at both zero and finite temperatures.


title: Dynamic sampling and information encoding in biochemical networks

abstract:
  Cells use biochemical networks to translate environmental information into
intracellular responses. These responses can be highly dynamic, but how the
information is encoded in these dynamics remains poorly understood. Here we
investigate the dynamic encoding of information in the ATP-induced calcium
responses of fibroblast cells, using a vectorial, or multi-time-point, measure
from information theory. We find that the amount of extracted information
depends on physiological constraints such as the sampling rate and memory
capacity of the downstream network, and is affected differentially by intrinsic
vs. extrinsic noise. By comparing to a minimal physical model, we find,
surprisingly, that the information is often insensitive to the detailed
structure of the underlying dynamics, and instead the decoding mechanism acts
as a simple low-pass filter. These results demonstrate the mechanisms and
limitations of dynamic information storage in cells.


title:
Finding Significant Fourier Coefficients: Clarifications,
  Simplifications, Applications and Limitations

abstract:
  Ideas from Fourier analysis have been used in cryptography for the last three
decades. Akavia, Goldwasser and Safra unified some of these ideas to give a
complete algorithm that finds significant Fourier coefficients of functions on
any finite abelian group. Their algorithm stimulated a lot of interest in the
cryptography community, especially in the context of `bit security'. This
manuscript attempts to be a friendly and comprehensive guide to the tools and
results in this field. The intended readership is cryptographers who have heard
about these tools and seek an understanding of their mechanics and their
usefulness and limitations. A compact overview of the algorithm is presented
with emphasis on the ideas behind it. We show how these ideas can be extended
to a `modulus-switching' variant of the algorithm. We survey some applications
of this algorithm, and explain that several results should be taken in the
right context. In particular, we point out that some of the most important bit
security problems are still open. Our original contributions include: a
discussion of the limitations on the usefulness of these tools; an answer to an
open question about the modular inversion hidden number problem.


title:
Logarithmic coefficients for certain subclasses of close-to-convex
  functions

abstract:
  Let $\mathcal{S}$ denote the class of functions analytic and univalent (i.e.
one-to-one) in the unit disk $\mathbb{D}=\{z\in\mathbb{C}:\, |z|<1\}$
normalized by $f(0)=0=f'(0)-1$. The logarithmic coefficients $\gamma_n$ of
$f\in\mathcal{S}$ are defined by $\log \frac{f(z)}{z}= 2\sum_{n=1}^{\infty}
\gamma_n z^n.$ In the present paper, we determine the sharp upper bounds for
$|\gamma_1|$, $|\gamma_2|$ and $|\gamma_3|$ when $f$ belongs to some familiar
subclasses of close-to-convex functions.


title: A Monte-Carlo Method for Making SDSS $u$-Band Magnitude more accurate

abstract:
  We develop a new Monte-Carlo-based method to convert the SDSS (Sloan Digital
Sky Survey) $u$-band magnitude to the SCUSS (South Galactic Cap of $u$-band Sky
Survey) $u$-band magnitude. Due to more accuracy of SCUSS $u$-band
measurements, the converted $u$-band magnitude becomes more accurate comparing
with the original SDSS $u$-band magnitude, in particular at the faint end. The
average $u$ (both SDSS and SCUSS) magnitude error of numerous main-sequence
stars with $0.2<g-r<0.8$ increase as $g$-band magnitude becomes fainter. When
$g=19.5$, the average magnitude error of SDSS $u$ is 0.11. When $g=20.5$, the
average SDSS $u$ error is up to 0.22. However, at this magnitude, the average
magnitude error of SCUSS $u$ is just half as much as that of SDSS $u$. The SDSS
$u$-band magnitudes of main-sequence stars with $0.2<g-r<0.8$ and $18.5<g<20.5$
are converted, therefore the maximum average error of converted $u$-band
magnitudes is 0.11. The potential application of this conversion is to derive
more accurate photometric metallicity calibration from SDSS observation,
especially for those distant stars. Thus, we can explore stellar metallicity
distributions either in the Galactic halo or some stream stars.


title: Urban Social Media Inequality: Definition, Measurements, and Application

abstract:
  Social media content shared today in cities, such as Instagram images, their
tags and descriptions, is the key form of contemporary city life. It tells
people where activities and locations that interest them are and it allows them
to share their urban experiences and self-representations. Therefore, any
analysis of urban structures and cultures needs to consider social media
activity. In our paper, we introduce the novel concept of social media
inequality. This concept allows us to quantitatively compare patterns in social
media activities between parts of a city, a number of cities, or any other
spatial areas. We define this concept using an analogy with the concept of
economic inequality. Economic inequality indicates how some economic
characteristics or material resources, such as income, wealth or consumption
are distributed in a city, country or between countries. Accordingly, we can
define social media inequality as the measure of the distribution of
characteristics from social media content shared in a particular geographic
area or between areas. An example of such characteristics is the number of
photos shared by all users of a social network such as Instagram in a given
city or city area, or the content of these photos. We propose that the standard
inequality measures used in other disciplines, such as the Gini coefficient,
can also be used to characterize social media inequality. To test our ideas, we
use a dataset of 7,442,454 public geo-coded Instagram images shared in
Manhattan during five months (March-July) in 2014, and also selected data for
287 Census tracts in Manhattan. We compare patterns in Instagram sharing for
locals and for visitors for all tracts, and also for hours in a 24-hour cycle.
We also look at relations between social media inequality and socio-economic
inequality using selected indicators for Census tracts.


title:
Crossover from one- to three-dimensional behavior in the S = 1/2
  Heisenberg antiferromagnet Cu(N2H5)2(SO4)2

abstract:
  From experimental and theoretical analyses of magnetic and specific-heat
properties, we present the complete magnetic phase diagram of the
quasi-one-dimensional antiferromagnet Cu(N$_2$H$_5$)$_2$(SO$_4$)$_2$. On
cooling and at zero magnetic field this compound enters a one-dimensional
regime with short-range magnetic correlations, marked by a broad maximum in the
specific heat and magnetic susceptibility at $T_\mathrm{max}\sim
2\,\mathrm{K}$, followed by an ordered antiferromagnetic phase below
$T_\mathrm{N}\sim 1\,\mathrm{K}$ induced by small interchain couplings. The
intermediate-temperate one-dimensional regime can be modeled using exact
quantum-transfer-matrix calculations, which perfectly describe the nonmonotonic
behavior of T_max as a function of the magnetic field, giving $J =
4.25\,\mathrm{K}$ for the intrachain exchange parameter. The analysis of
magnetic specific-heat and susceptibility data at low temperature indicates
that the interchain exchange couplings are an order of magnitude smaller than
the coupling inside the chains.


title: Oscillating Chiral Tensor Spectrum from Axionic Inflation

abstract:
  We study the axionic inflation with a modulated potential and examine if the
primordial tensor power spectrum exhibits oscillatory feature, which is
testable with future space-based gravitational wave experiments such as DECIGO
and BBO. In the case of the single-field axion monodromy inflation, it turns
out that it is difficult to detect the oscillation in the spectrum due to
suppression of the sub-Planckian decay constant of axion. On the other hand, in
the case of aligned chromo-natural inflation where the axion is coupled to a
SU(2) gauge field, it turns out that the sizable oscillation in the tensor
spectrum can occur due to the enhancement of chiral gravitational waves sourced
by the gauge field. We expect that this feature will be a new probe to axion
phenomenologies in early universe through the chiral gravitational waves.


title:
Hierarchical Decentralized Robust Optimal Design for Homogeneous Linear
  Multi-Agent Systems

abstract:
  This paper proposes novel approaches to design hierarchical decentralized
robust controllers for homogeneous linear multi-agent systems (MASs) perturbed
by disturbances/noise. Firstly, based on LQR method, we present a systematic
procedure to design hierarchical decentralized optimal stabilizing controllers
for MASs without disturbances/noise. Next, a method for deriving reduced-order
hierarchical decentralized stabilizing controllers is presented by suitable
selections of the weighting matrices in the LQR performance index. Secondly,
the hierarchical decentralized robust controller designs in terms of
$H_{\infty}$ and $H_{2}$ norms are introduced, which include two different
scenarios namely general and LQR-based synthesis. For the general synthesis,
the robust controller gains are computed as solutions of a distributed convex
optimization problem with LMI constraints. On the other hand, for the LQR-based
design, the robust controller gains obtained from the general synthesis are
further verified as LQR stabilizing gains to be unified with the LQR-based
design when there are no disturbances/noise. This results in a hierarchical
decentralized inverse optimal control problem, for which we will propose a new
method to resolve it. Finally, several numerical examples are presented to
illustrate the effectiveness of the proposed approaches.


title: Coherent and Dynamic Beam Splitting based on Light Storage in Cold Atoms

abstract:
  We demonstrate a coherent and dynamic beam splitter based on light storage in
cold atoms. An input weak laser pulse is first stored in a cold atom ensemble
via electromagnetically-induced transparency (EIT). A set of
counter-propagating control fields, applied at a later time, retrieves the
stored pulse into two output spatial modes. The high visibility interference
between the two output pulses clearly demonstrates that the beam splitting
process is coherent. Furthermore, by manipulating the control lasers, it is
possible to dynamically control the storage time, the power splitting ratio,
the relative phase, and the optical frequencies of the output pulses. The
active beam splitter demonstrated in this work is expected to significantly
reduce the resource requirement in photonic quantum information and in
all-optical information processing as a single cold atom ensemble can
functionally replace a variety of optical elements, including beam splitters,
mirrors, phase shifters, and optical quantum memories.


title:
Frequency Comb Generation in 300 nm Thick SiN
  Concentric-Racetrack-Resonators: Overcoming the Material Dispersion Limit

abstract:
  Kerr nonlinearity based frequency combs and solitons have been generated from
on-chip optical microresonators with high quality factors and global or local
anomalous dispersion. However, fabrication of such resonators usually requires
materials and/or processes that are not standard in semiconductor manufacturing
facilities. Moreover, in certain frequency regimes such as visible and
ultra-violet, the large normal material dispersion makes it extremely difficult
to achieve anomalous dispersion. Here we present a concentric racetrack-shaped
resonator that achieves anomalous dispersion in a 300 nm thick silicon nitride
film, suitable for semiconductor manufacturing but previously thought to result
only in waveguides with high normal dispersion, a high intrinsic Q of 1.5
million, and a novel mode-selective coupling scheme that allows coherent combs
to be generated. We also provide evidence suggestive of soliton-like pulse
formation in the generated comb. Our method can achieve anomalous dispersion
over moderately broad bandwidth for resonators at almost any wavelength while
still maintaining material and process compatibility with high-volume
semiconductor manufacturing.


title: Interacting in-plane molecular dipoles in a zig-zag chain

abstract:
  The system with externally polarized dipole molecules at half-filling moving
along a one-dimensional zig-zag chain is studied theoretically, including the
ground-state phase diagram. The dipoles are oriented in-plane. Together with
the geometry of the chain this gives rise to a bond-alternating nearest
neighbor interaction due to simultaneous attractive and repulsive interactions.
Because of the quantum Zeno effect due to the reactive nature of molecules the
system can be treated as hard-core. By tuning the ratio between the
nearest-neighbor interaction and hopping, various phases can be accessed by
controlling the polarization angle. In the ultra-strong coupling limit, the
system simplifies to a frustrated extended axial Ising model. For the small
coupling limit, qualitative discussion of the ordering behavior using effective
field theory arguments is provided. We show that when chain angle is small, the
system mostly exhibits BKT-type phase transitions, whereas large chain angle
would drive the system into a gapped (Ising) dimerized phase, where the hopping
strength is closely related to the orientation of dimerized pairs.


title:
Nodeless pairing in superconducting copper-oxide monolayer films on
  Bi2Sr2CaCu2O8+{\delta}

abstract:
  The pairing mechanism of high-temperature superconductivity in cuprates
remains the biggest unresolved mystery in condensed matter physics. To solve
the problem, one of the most effective approaches is to investigate directly
the superconducting CuO2 layers. Here, by growing CuO2 monolayer films on
Bi2Sr2CaCu2O8+{\delta} substrates, we identify two distinct and spatially
separated energy gaps centered at the Fermi energy, a smaller U-like gap and a
larger V-like gap on the films, and study their interactions with alien atoms
by low-temperature scanning tunneling microscopy. The newly discovered U-like
gap exhibits strong phase coherence and is immune to scattering by K, Cs and Ag
atoms, suggesting its nature as a nodeless superconducting gap in the CuO2
layers, whereas the V-like gap agrees with the well-known pseudogap state in
the underdoped regime. Our results support an s-wave superconductivity in
Bi2Sr2CaCu2O8+{\delta}, which, we propose, originates from the
modulation-doping resultant two-dimensional hole liquid confined in the CuO2
layers.


title:
On Gaussian Comparison Inequality and Its Application to Spectral
  Analysis of Large Random Matrices

abstract:
  Recently, Chernozhukov, Chetverikov, and Kato [Ann. Statist. 42 (2014)
1564--1597] developed a new Gaussian comparison inequality for approximating
the suprema of empirical processes. This paper exploits this technique to
devise sharp inference on spectra of large random matrices. In particular, we
show that two long-standing problems in random matrix theory can be solved: (i)
simple bootstrap inference on sample eigenvalues when true eigenvalues are
tied; (ii) conducting two-sample Roy's covariance test in high dimensions. To
establish the asymptotic results, a generalized $\epsilon$-net argument
regarding the matrix rescaled spectral norm and several new empirical process
bounds are developed and of independent interest.


title: NMR parameters in gapped graphene systems

abstract:
  We calculate the nuclear spin-lattice relaxation time and the Knight shift
for the case of gapped graphene systems. Our calculations consider both the
massive and massless gap scenarios. Both the spin-lattice relaxation time and
the Knight shift depend on temperature, chemical potential, and the value of
the electronic energy gap. In particular, at the Dirac point, the electronic
energy gap has stronger effects on the system nuclear magnetic resonance
parameters in the case of the massless gap scenario. Differently, at large
values of the chemical potential, both gap scenarios behave in a similar way
and the gapped graphene system approaches a Fermi gas from the nuclear magnetic
resonance parameters point of view. Our results are important for nuclear
magnetic resonance measurements that target the $^{13}$C active nuclei in
graphene samples.


title:
Iterative Multi-domain Regularized Deep Learning for Anatomical
  Structure Detection and Segmentation from Ultrasound Images

abstract:
  Accurate detection and segmentation of anatomical structures from ultrasound
images are crucial for clinical diagnosis and biometric measurements. Although
ultrasound imaging has been widely used with superiorities such as low cost and
portability, the fuzzy border definition and existence of abounding artifacts
pose great challenges for automatically detecting and segmenting the complex
anatomical structures. In this paper, we propose a multi-domain regularized
deep learning method to address this challenging problem. By leveraging the
transfer learning from cross domains, the feature representations are
effectively enhanced. The results are further improved by the iterative
refinement. Moreover, our method is quite efficient by taking advantage of a
fully convolutional network, which is formulated as an end-to-end learning
framework of detection and segmentation. Extensive experimental results on a
large-scale database corroborated that our method achieved a superior detection
and segmentation accuracy, outperforming other methods by a significant margin
and demonstrating competitive capability even compared to human performance.


title: Neural Name Translation Improves Neural Machine Translation

abstract:
  In order to control computational complexity, neural machine translation
(NMT) systems convert all rare words outside the vocabulary into a single unk
symbol. Previous solution (Luong et al., 2015) resorts to use multiple numbered
unks to learn the correspondence between source and target rare words. However,
testing words unseen in the training corpus cannot be handled by this method.
And it also suffers from the noisy word alignment. In this paper, we focus on a
major type of rare words -- named entity (NE), and propose to translate them
with character level sequence to sequence model. The NE translation model is
further used to derive high quality NE alignment in the bilingual training
corpus. With the integration of NE translation and alignment modules, our NMT
system is able to surpass the baseline system by 2.9 BLEU points on the Chinese
to English task.


title:
Momentum and Energy Dependent Resolution Function of the ARCS Neutron
  Chopper Spectrometer at High Momentum Transfer: Comparing Simulation and
  Experimen

abstract:
  Inelastic neutron scattering at high momentum transfers (i.e. $Q\ge20$ {\AA})
or DINS provides direct observation of the momentum distribution of light
atoms, making it a powerful probe for studying single-particle motions in
liquids and solids. The quantitative analysis of DINS data requires an accurate
knowledge of the instrument resolution function $R_{i}({Q},E)$ at each $Q$ and
energy transfer $E$, where the label $i$ indicates whether the resolution was
experimentally observed $i={obs}$ or simulated $i=sim$. Here, we describe two
independent methods for determining the total resolution function
$R_{i}({Q},E)$ of the ARCS neutron instrument at the Spallation Neutron Source,
Oak Ridge National Laboratory. The first method uses experimental data from an
archetypical system (liquid $^4$He) studied with DINS, which are then
numerically deconvoluted using its previously determined intrinsic scattering
function to yield $R_{obs}({Q},E)$. The second approach uses accurate Monte
Carlo simulations of the ARCS spectrometer, which account for all instrument
contributions, coupled to a representative scattering kernel to reproduce the
experimentally observed response $S({Q},E)$. Using a delta function as
scattering kernel, the simulation yields a resolution function $R_{sim}({Q},E)$
with comparable lineshape and features as $R_{obs}({Q},E)$, but somewhat
narrower due to the ideal nature of the model. Using each of these two
$R_{i}({Q},E)$ separately, we extract characteristic parameters of liquid
$^4$He such as the intrinsic linewidth $\alpha_2$ (which sets the atomic
kinetic energy $\langle K\rangle\sim\alpha_2$) in the normal liquid and the
Bose-Einstein condensate parameter $n_0$ in the superfluid phase. The extracted
$\alpha_2$ values agree well with previous measurements, independently of which
$R_i(Q,y)$ is used to analyze the data.


title:
Mechanical Properties of Phosphorene Nanotubes: A Density Functional
  Tight-Binding Study

abstract:
  Using density functional tight-binding method, we studied the elastic
properties, deformation and failure of armchair (AC) and zigzag (ZZ)
phosphorene nano tubes (PNTs) under uniaxial tensile strain. We found that the
deformation and failure of PNTs are very anisotropic. For ZZ PNTs, three
deformation phases are recognized: The primary linear elastic phase, which is
associated with the interactions between the neighboring puckers, succeeded by
the bond rotation phase, where the puckered configuration of phosphorene is
smoothed via bond rotation, and lastly the bond elongation phase, where the P-P
bonds are directly stretched up to the maximally allowed limit and the failure
is initiated by the rupture of the most stretched bonds.


title:
A fractional kinetic process describing the intermediate time behaviour
  of cellular flows

abstract:
  This paper studies the intermediate time behaviour of a small random
perturbation of a periodic cellular flow. Our main result shows that on time
scales shorter than the diffusive time scale, the limiting behaviour of
trajectories that start close enough to cell boundaries is a fractional kinetic
process: A Brownian motion time changed by the local time of an independent
Brownian motion. Our proof uses the Freidlin-Wentzell framework, and the key
step is to establish an analogous averaging principle on shorter time scales.
As a consequence of our main theorem, we obtain a homogenization result for the
associated advection-diffusion equation. We show that on intermediate time
scales the effective equation is a fractional time PDE that arises in modelling
anomalous diffusion.


title: Quantum critical behavior of the superfluid-Mott glass transition

abstract:
  We investigate the zero-temperature superfluid to insulator transitions in a
diluted two-dimensional quantum rotor model with particle-hole symmetry. We map
the Hamiltonian onto a classical $(2+1)$-dimensional XY model with columnar
disorder which we analyze by means of large-scale Monte Carlo simulations. For
dilutions below the lattice percolation threshold, the system undergoes a
generic superfluid-Mott glass transition. In contrast to other quantum phase
transitions in disordered systems, its critical behavior is of conventional
power-law type with universal (dilution-independent) critical exponents
$z=1.52(3)$, $\nu=1.16(5)$, $\beta/\nu= 0.48(2)$, $\gamma/\nu=2.52(4)$, and
$\eta=-0.52(4)$. These values agree with and improve upon earlier Monte-Carlo
results [Phys. Rev. Lett. 92, 015703 (2004)] while (partially) excluding other
findings in the literature. As a further test of universality, we also consider
a soft-spin version of the classical Hamiltonian. In addition, we study the
percolation quantum phase transition across the lattice percolation threshold;
its critical behavior is governed by the lattice percolation exponents in
agreement with recent theoretical predictions. We relate our results to a
general classification of phase transitions in disordered systems, and we
briefly discuss experiments.


title:
Numerical Optimization Algorithm of Wavefront Phase Retrieval from
  Multiple Measurements

abstract:
  Wavefront phase retrieval from a set of intensity measurements can be
formulated as an optimization problem. Two nonconvex objective models (MLP and
its variants LS) based on maximum likelihood estimation are investigated. We
develop numerical optimization algorithms for real-valued function of complex
variables and apply them to solve the wavefront phase retrieval problem
efficiently. Numerical simulation is given with application to three wavefront
phase retrieval problems. LS model shows better numerical performances than MLP
model. An explanation for this is that the distribution of the eigenvalues of
Hessian matrix of LS model is more clustered than MLP model. LBFGS shows more
robust performance and takes fewer calculations than other line search methods.


title: Topologically stable gapless phases in nonsymmorphic superconductors

abstract:
  We study topological stability of nodes in nonsymmorphic superconductors
(SCs). In particular, we demonstrate that line nodes in nonsymmirphic
odd-parity SCs are protected by the interplay between topology and
nonsymmorphic symmetry. As an example, it is shown that the
$E_{2u}$-superconducting state of UPt$_3$ hosts the topologically stable line
node at the Brillouin zone face. Our theory indicates that the existence of
spin-orbit coupling is essential for protecting such a line node, complementing
the Norman's group theory argument. Developing the topological arguments, we
also argue generalization to point nodes and to other symmetry cases beyond the
group theory arguments.


title:
Spin polarization in high density quark matter under a strong external
  magnetic field

abstract:
  In high density quark matter under a strong external magnetic field, possible
phases are investigated by using the two-flavor Nambu-Jona-Lasinio model with
tensor-type four-point interaction between quarks, as well as the
axial-vector-type four-point interaction. In the tensor-type interaction under
the strong external magnetic field, it is shown that a quark spin polarized
phase is realized in all regions of the quark chemical potential under
consideration within the lowest Landau level approximation. In the
axial-vector-type interaction, it is also shown that the quark spin polarized
phase appears in the wide range of the quark chemical potential. In both the
interactions, the quark mass in zero and small chemical potential regions
increases which indicates that the chiral symmetry breaking is enhanced, namely
the magnetic catalysis occurs.


title:
A Quadratic Programming Relaxation Approach to Compute-and-Forward
  Network Coding Design

abstract:
  Using physical layer network coding, compute-and-forward is a promising
relaying scheme that effectively exploits the interference between users and
thus achieves high rates. In this paper, we consider the problem of finding the
optimal integer-valued coefficient vector for a relay in the
compute-and-forward scheme to maximize the computation rate at that relay.
Although this problem turns out to be a shortest vector problem, which is
suspected to be NP-hard, we show that it can be relaxed to a series of
equality-constrained quadratic programmings. The solutions of the relaxed
problems serve as real-valued approximations of the optimal coefficient vector,
and are quantized to a set of integer-valued vectors, from which a coefficient
vector is selected. The key to the efficiency of our method is that the
closed-form expressions of the real-valued approximations can be derived with
the Lagrange multiplier method. Numerical results demonstrate that compared
with the existing methods, our method offers comparable rates at an
impressively low complexity.


title:
Preasymptotics and asymptotics of approximation numbers of anisotropic
  Sobolev embeddings

abstract:
  In this paper, we obtain the preasymptotic and asymptotic behavior and strong
equivalences of the approximation numbers of the embeddings from the
anisotropic Sobolev spaces $W_2^{\bf R}(\Bbb T^d)$ to $L_2(\Bbb T^d)$. We also
get the preasymptotic behavior of the approximation numbers of the embeddings
from the limit spaces $W_2^{\infty}(\Bbb T^d)$ of the anisotropic Sobolev
spaces $W_2^{\bf R}(\Bbb T^d)$ to $L_2(\Bbb T^d)$. We show that both the above
embedding problems are intractable and do not suffer from the curse of
dimensionality.


title:
Unsharpness of generalized measurement and its effects in entropic
  uncertainty relations

abstract:
  Under the scenario of generalized measurements, it can be questioned how much
of quantum uncertainty can be attributed to measuring device, independent of
the uncertainty in the measured system. On the course to answer the question,
we suggest a new class of entropic uncertainty relation that differentiates
quantum uncertainty from device imperfection due to the unsharpness of
measurement. In order to quantify the unsharpness, we {suggest} and analyze the
quantity that characterizes the uncertainty in the measuring device, based on
Shannon entropy. Using the quantity, we obtain a new lower bound of entropic
uncertainty with unsharpness and it has been shown that the relation can also
be obtained under the scenario that sharp observables are affected by the white
noise and amplitude damping.


title: Borelic pairs for stratified algebras

abstract:
  We determine all values of the parameters for which the cell modules form a
standard system, for a class of cellular diagram algebras including partition,
Brauer, walled Brauer, Temperley-Lieb and Jones algebras. For this, we develop
and apply a general theory of algebras with Borelic pairs. The theory is also
applied to give new uniform proofs of the cellular and quasi-hereditary
properties of the diagram algebras and to construct quasi-hereditary 1-covers,
in the sense of Rouquier, with exact Borel subalgebras, in the sense of
K\"onig. Another application of the theory leads to a proof that
Auslander-Dlab-Ringel algebras admit exact Borel subalgebras.


title: Enhanced proton acceleration in an applied longitudinal magnetic field

abstract:
  Using two-dimensional particle-in-cell simulations, we examine how an
externally applied strong magnetic impacts proton acceleration in
laser-irradiated solid-density targets. We find that a kT-level external
magnetic field can sufficiently inhibit transverse transport of hot electrons
in a flat laser-irradiated target. While the electron heating by the laser
remains mostly unaffected, the reduced electron transport during proton
acceleration leads to an enhancement of maximum proton energies and the overall
number of energetic protons. The resulting proton beam is much better
collimated compared to a beam generated without applying a kT-level magnetic
field. A factor of three enhancement of the laser energy conversion efficiency
into multi-MeV protons is another effect of the magnetic field. The required kT
magnetic fields are becoming feasible due to a significant progress that has
been made in generating magnetic fields with laser-driven coils using ns-long
laser pulses. The predicted improved characteristics of laser-driven proton
beams would be critical for a number of applications.


title:
Scalable Semantic Matching of Queries to Ads in Sponsored Search
  Advertising

abstract:
  Sponsored search represents a major source of revenue for web search engines.
This popular advertising model brings a unique possibility for advertisers to
target users' immediate intent communicated through a search query, usually by
displaying their ads alongside organic search results for queries deemed
relevant to their products or services. However, due to a large number of
unique queries it is challenging for advertisers to identify all such relevant
queries. For this reason search engines often provide a service of advanced
matching, which automatically finds additional relevant queries for advertisers
to bid on. We present a novel advanced matching approach based on the idea of
semantic embeddings of queries and ads. The embeddings were learned using a
large data set of user search sessions, consisting of search queries, clicked
ads and search links, while utilizing contextual information such as dwell time
and skipped ads. To address the large-scale nature of our problem, both in
terms of data and vocabulary size, we propose a novel distributed algorithm for
training of the embeddings. Finally, we present an approach for overcoming a
cold-start problem associated with new ads and queries. We report results of
editorial evaluation and online tests on actual search traffic. The results
show that our approach significantly outperforms baselines in terms of
relevance, coverage, and incremental revenue. Lastly, we open-source learned
query embeddings to be used by researchers in computational advertising and
related fields.


title: Auxiliary-field quantum Monte Carlo methods in nuclei

abstract:
  Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal
and ground state properties of correlated quantum many-body systems in model
spaces that are many orders of magnitude larger than those that can be treated
by conventional diagonalization methods. We review recent developments and
applications of these methods in nuclei using the framework of the
configuration-interaction shell model.

categories: nucl-th cond-mat.quant-gas cond-mat.str-el physics.comp-ph


title: CHY-Graphs on a Torus

abstract:
  Recently, we proposed a new approach using a punctured Elliptic curve in the
CHY framework in order to compute one-loop scattering amplitudes. In this note,
we further develop this approach by introducing a set of connectors, which
become the main ingredient to build integrands on $\mathfrak{M}_{1,n}$, the
moduli space of n-punctured Elliptic curves. As a particular application, we
study the $\Phi^3$ bi-adjoint scalar theory. We propose a set of rules to
construct integrands on $\mathfrak{M}_{1,n}$ from $\Phi^ 3$ integrands on
$\mathfrak{M}_{0,n}$, the moduli space of n-punctured spheres. We illustrate
these rules by computing a variety of $\Phi^3$ one-loop Feynman diagrams.
Conversely, we also provide another set of rules to compute the corresponding
CHY-integrand on $\mathfrak{M}_{1,n}$ by starting instead from a given $\Phi^
3$ one-loop Feynman diagram. In addition, our results can easily be extended to
higher loops.


title:
Downlink Cell Association and Load Balancing for Joint Millimeter
  Wave-Microwave Cellular Networks

abstract:
  The integration of millimeter-wave base stations (mmW-BSs) with conventional
microwave base stations ($\mu$W-BSs) is a promising solution for enhancing the
quality-of-service (QoS) of emerging 5G networks. However, the significant
differences in the signal propagation characteristics over the mmW and $\mu$W
frequency bands will require novel cell association schemes cognizant of both
mmW and $\mu$W systems. In this paper, a novel cell association framework is
proposed that considers both the blockage probability and the achievable rate
to assign user equipments (UEs) to mmW-BSs or $\mu$W-BSs. The problem is
formulated as a one-to-many matching problem with minimum quota constraints for
the BSs that provides an efficient way to balance the load over the mmW and
$\mu$W frequency bands. To solve the problem, a distributed algorithm is
proposed that is guaranteed to yield a Pareto optimal and two-sided stable
solution. Simulation results show that the proposed matching with minimum quota
(MMQ) algorithm outperforms the conventional max-RSSI and max-SINR cell
association schemes. In addition, it is shown that the proposed MMQ algorithm
can effectively balance the number of UEs associated with the $\mu$W-BSs and
mmW-BSs and achieve further gains, in terms of the average sum rate.


title: Dai-Freed theorem and topological phases of matter

abstract:
  We describe a physics derivation of theorems due to Dai and Freed about the
Atiyah-Patodi-Singer eta-invariant which is important for anomalies and
topological phases of matter. This is done by studying a massive fermion. The
key role is played by the wave function of the ground state in the Hilbert
space of the fermion in the large mass limit. The ground state takes values in
the determinant line bundle and has nontrivial Berry phases which characterize
the low energy topological phases.


title: JUDE: An Ultraviolet Imaging Telescope Pipeline

abstract:
  The Ultraviolet Imaging Telescope (UVIT) was launched as part of the
multi-wavelength Indian ASTROSAT mission on 28 September, 2015 into a low Earth
orbit. A 6-month performance verification (PV) phase ended in March 2016, and
the instrument is now in the general observing phase. UVIT operates in three
channels: visible, near-ultraviolet (NUV) and far-ultraviolet (FUV), each with
a choice of broad and narrow band filters, and has NUV and FUV gratings for
low-resolution spectroscopy. We have written a software package (JUDE) to
convert the Level1 data from UVIT into scientifically useful photon lists and
images. The routines are written in the GNU Data Language (GDL) and are
compatible with the IDL software package. We use these programs in our own
scientific work, and will continue to update the programs as we gain better
understanding of the UVIT instrument and its performance. We have released JUDE
under an Apache License.


title:
Resonance decay effect on conserved number fluctuations in a hadron
  resonance gas model

abstract:
  We study the effect of charged secondaries coming from resonance decay on the
net-baryon, net-charge and net-strangeness fluctuations in high energy
heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize
the importance of including weak decays along with other resonance decays in
the HRG, while comparing with the experimental observables. The effect of
kinematic cuts on resonances and primordial particles on the conserved number
fluctuations are also studied. The HRG model calculations with the inclusion of
resonance decays and kinematical cuts are compared with the recent experimental
data from STAR and PHENIX experiments. We find a good agreement between our
model calculations and the experimental measurements for both net-proton and
net-charge distributions.


title: Extremal Triangular Chain Graphs for Bond Incident Degree (BID) Indices

abstract:
  A general expression for calculating the bond incident degree (BID) indices
of certain triangular chain graphs is derived. The extremal triangular chain
graphs with respect to several well known BID indices are also characterized
over a particular collection of triangular chain graphs.


title: Influence of the Magnetic Field on Oscillation Spectra in Solar Faculae

abstract:
  In this work, we studied oscillation parameters in faculae above magnetic
knots and in the adjacent to them areas. Using SDO data we analysed
oscillations in magnetic strength, Doppler velocity, and intensity signals for
the lower photosphere, and in intensity for the higher levels. We found that in
the magnetic field strength oscillation spectra in magnetic knots, peaks at a
frequency of about 4.8 mHz appear, while there are no such frequencies in the
adjacent facular patches of a moderate field strength. On the contrary, Doppler
velocity photospheric oscillation spectra are similar for these types of
regions: in both cases, the significant peaks are in the 2.5--4.5 mHz range,
though the oscillations in magnetic knots are 2--3 times weaker than those at
the facular periphery. At the upper photosphere, the dominant frequencies in
magnetic knots are 0.5--1 mHz higher than in the medium-field regions. The
transition region oscillations above magnetic knots mainly concentrate in the
3--6 mHz range, and those above moderate-field patches concentrate below 3 mHz.


title: Viewpoint: duality for fermionic vortices

abstract:
  This is a version (less professional editing, more details and jokes) of an
APS Physics Viewpoint about three recent papers extending charge-vortex duality
to fermionic vortices.


title:
Determinants of Structural Stability in Complex Ecological and
  Biological Networks: the Google Matrix Approach Determinants of stability in
  biological and ecological networks: the Google matrix approach

abstract:
  Mays celebrated theoretical work of the 70s contradicted the established
paradigm by demonstrating that complexity leads to instability in biological
systems. Here Mays random-matrix modelling approach is generalized to realistic
large-scale webs of species interactions, be they structured by networks of
competition, mutualism or both. Simple relationships are found to govern these
otherwise intractable models, and control the parameter ranges for which
biological systems are stable and feasible. Our analysis of model and real
empirical networks is only achievable upon introducing a simplifying
Google-matrix reduction scheme, which in the process, yields a practical
ecological eigenvalue stability index. These results provide an understanding
on how network topology, especially connectance, influences species stable
coexistence. Constraints controlling feasibility (positive equilibrium
populations) in these systems, are found more restrictive than those
controlling stability, helping explain the enigma of why many classes of
feasible ecological models are nearly always stable.


title:
Complete Description of Matching Polytopes with One Linearized Quadratic
  Term for Bipartite Graphs

abstract:
  We consider, for complete bipartite graphs, the convex hulls of
characteristic vectors of all matchings, extended by a binary entry indicating
whether the matching contains two specific edges. These polytopes are
associated to the quadratic matching problems with a single linearized
quadratic term. We provide a complete irredundant inequality description, which
settles a conjecture by Klein (Ph.D. thesis, TU Dortmund, 2015). In addition,
we also derive facetness and separation results for the polytopes. The
completeness proof is based on a geometric relationship to a matching polytope
of a nonbipartite graph. Using standard techniques, we finally extend the
result to capacitated b-matchings.


title: Goal-oriented optimal approximations of Bayesian linear inverse problems

abstract:
  We propose optimal dimensionality reduction techniques for the solution of
goal-oriented linear-Gaussian inverse problems, where the quantity of interest
(QoI) is a function of the inversion parameters. These approximations are
suitable for large-scale applications. In particular, we study the
approximation of the posterior covariance of the QoI as a low-rank negative
update of its prior covariance, and prove optimality of this update with
respect to the natural geodesic distance on the manifold of symmetric positive
definite matrices. Assuming exact knowledge of the posterior mean of the QoI,
the optimality results extend to optimality in distribution with respect to the
Kullback-Leibler divergence and the Hellinger distance between the associated
distributions. We also propose approximation of the posterior mean of the QoI
as a low-rank linear function of the data, and prove optimality of this
approximation with respect to a weighted Bayes risk. Both of these optimal
approximations avoid the explicit computation of the full posterior
distribution of the parameters and instead focus on directions that are well
informed by the data and relevant to the QoI. These directions stem from a
balance among all the components of the goal-oriented inverse problem: prior
information, forward model, measurement noise, and ultimate goals. We
illustrate the theory using a high-dimensional inverse problem in heat
transfer.


title: Large bias for integers with prime factors in arithmetic progressions

abstract:
  We prove an asymptotic formula for the number of integers $\leq x$ which can
be written as the product of $k ~(\geq 2)$ distinct primes $p_1\cdots p_k$ with
each prime factor in an arithmetic progression $p_j\equiv a_j \bmod q$, $(a_j,
q)=1$ $(q \geq 3, 1\leq j\leq k)$. For any $A>0$, our result is uniform for
$2\leq k\leq A\log\log x$. Moreover, we show that, there are large biases
toward certain arithmetic progressions $(a_1 \bmod q, \cdots, a_k \bmod q)$,
and such biases have connections with Mertens' theorem and the least prime in
arithmetic progressions.


title:
Sampling-based Incremental Information Gathering with Applications to
  Robotic Exploration and Environmental Monitoring

abstract:
  In this article, we propose a sampling-based motion planning algorithm
equipped with an information-theoretic convergence criterion for incremental
informative motion planning. The proposed approach allows dense map
representations and incorporates the full state uncertainty into the planning
process. The problem is formulated as a constrained maximization problem. Our
approach is built on rapidly-exploring information gathering algorithms and
benefits from advantages of sampling-based optimal motion planning algorithms.
We propose two information functions and their variants for fast and online
computations. We prove an information-theoretic convergence for an entire
exploration and information gathering mission based on the least upper bound of
the average map entropy. A natural automatic stopping criterion for
information-driven motion control results from the convergence analysis. We
demonstrate the performance of the proposed algorithms using three scenarios:
comparison of the proposed information functions and sensor configuration
selection, robotic exploration in unknown environments, and a wireless signal
strength monitoring task in a lake from a publicly available dataset collected
using an autonomous surface vehicle.


title:
A cosmographic analysis of the transition to acceleration using SN-Ia
  and BAO

abstract:
  We explore the distance-redshift relation using a cosmographic methodology,
and show how the cosmographic parameters can be used to determine the redshift
of transition from deceleration to acceleration. Such a transition at a low
redshift occupies only a small region of the available parameter space, and the
prior assumption of an early period of deceleration can significantly change
the posterior constraints. We use available type Ia Supernovae (SN-Ia) and
Baryon Acoustic Oscillation (BAO) data sets to determine the cosmographic
deceleration $q_0$, jerk $j_0$, snap $s_0$ and lerk $l_0$ parameters. The
parameters are consistent with the $\Lambda$CDM model for a flat universe
within 2-sigma. We derive constraints on the redshift of transition from
deceleration to acceleration for the different expansions, and find $z_{\rm
acc} > 0.14$ at 95% confidence in the most conservative case.


title: On discrete evolutionary dynamics driven by quadratic interactions

abstract:
  After an introduction to the general topic of models for a given locus of a
diploid population whose quadratic dynamics is determined by a fitness
landscape, we consider more specifically the models that can be treated using
genetic (or train) algebras. In this setup, any quadratic offspring interaction
can produce any type of offspring and after the use of specific changes of
basis, we study the evolution and possible stability of some examples. We also
consider some examples that cannot be treated using the framework of genetic
algebras. Among these are bistochastic matrices.


title: Join-continuity + Hypercontinuity = Prime continuity

abstract:
  A remarkable result due to Kou, Liu & Luo states that the condition of
continuity for a dcpo can be split into quasi-continuity and meet-continuity.
Their argument contained a gap, however, which is probably why the authors of
the monograph Continuous Lattices and Domains used a different (and fairly
sophisticated) sequence of lemmas in order to establish the result. In this
note we show that by considering the Stone dual, that is, the lattice of
Scott-open subsets, a straightforward proof may be given. We do this by showing
that a complete lattice is prime-continuous if and only if it is
join-continuous and hypercontinuous. A pleasant side effect of this approach is
that the characterisation of continuity by Kou, Liu & Luo also holds for
posets, not just dcpos.


title:
The symbol-pair distance distribution of repeated-root cyclic codes over
  $\mathbb{F}_{p^m}$

abstract:
  Symbol-pair codes are proposed to protect against pair errors in symbol-pair
read channels. One of the most important task in symbol-pair coding theory is
to determine the minimum pair-distance of symbol-pair codes. In this paper, we
investigate the symbol-pair distances of cyclic codes of length $p^e$ over
$\mathbb{F}_{p^m}$. The exact symbol-pair distances of all cyclic codes of such
length are determined.


title: Inertial-particle accelerations in turbulence: a Lagrangian closure

abstract:
  The distribution of particle accelerations in turbulence is intermittent,
with non-Gaussian tails that are quite different for light and heavy particles.
In this article we analyse a closure scheme for the acceleration fluctuations
of light and heavy inertial particles in turbulence, formulated in terms of
Lagrangian correlation functions of fluid tracers. We compute the variance and
the flatness of inertial particle accelerations and we discuss their dependency
on the Stokes number. The closure incorporates effects induced by the
Lagrangian correlations along the trajectories of fluid tracers, and its
predictions agree well with results of direct numerical simulations of inertial
particles in turbulence, provided that the effects induced by the inertial
preferential sampling of heavy/light particles outside/inside vortices are
negligible. In particular, the scheme predicts the correct functional behaviour
of the acceleration variance, as a function of Stokes, as well as the presence
of a minimum/maximum for the flatness of the acceleration of heavy/light
particles, in good qualitative agreement with numerical data. We also show that
the closure works well when applied to the Lagrangian evolution of particles
using a stochastic surrogate for the underlying Eulerian velocity field. Our
results support the conclusion that there exist important contributions to the
statistics of the acceleration of inertial particles independent of the
preferential sampling. For heavy particles we observe deviations between the
predictions of the closure scheme and direct numerical simulations, at Stokes
numbers of order unity. For light particles the deviation occurs for larger
Stokes numbers.


title:
Near-Infrared Imaging of Barred Halo Dominated Low Surface Brightness
  Galaxies

abstract:
  We present a near-infrared (NIR) imaging study of barred low surface
brightness (LSB) galaxies using the TIFR near-infrared Spectrometer and Imager
(TIRSPEC). LSB galaxies are dark matter dominated, late type spirals that have
low luminosity stellar disks but large neutral hydrogen (HI) gas disks. Using
SDSS images of a very large sample of LSB galaxies derived from the literature,
we found that the barred fraction is only 8.3%. We imaged twenty five barred
LSB galaxies in the J, H, K$_S$ wavebands and twenty nine in the K$_S$ band.
Most of the bars are much brighter than their stellar disks, which appear to be
very diffuse. Our image analysis gives deprojected mean bar sizes of
$R_{b}/R_{25}$ = 0.40 and ellipticities $e$ $\approx$ 0.45, which are similar
to bars in high surface brightness galaxies. Thus, although bars are rare in
LSB galaxies, they appear to be just as strong as bars found in normal
galaxies. There is no correlation of $R_{b}/R_{25}$ or $e$ with the relative HI
or stellar masses of the galaxies. In the (J-K$_S$) color images most of the
bars have no significant color gradient which indicates that their stellar
population is uniformly distributed and confirms that they have low dust
content.


title: On a square-ice analogue of plane partitions

abstract:
  We study a one-parameter family ($\ell=1,2,3,\ldots$) of configurations that
are square-ice analogues of plane partitions. Using an algorithm due to Bratley
and McKay, we carry out exact enumerations in order to study their asymptotic
behaviour and establish, via Monte Carlo simulations as well as explicit
bounds, that the asymptotic behaviour is similar to that of plane partitions.
We finally carry out a series analysis and provide independent estimates for
the asymptotic behaviour.


title:
Kondo effect at low electron density and high particle-hole asymmetry in
  1D, 2D, and 3D

abstract:
  Using the perturbative scaling and the NRG, we study the characteristic
energy scales in the Kondo impurity problem as a function of the exchange
coupling constant $J$ and the conduction electron density. We discuss the
relation between the impurity binding energy $\Delta E$ and the Kondo
temperature $T_K$. We find that the two are proportional only for large values
of $J$, whereas in the weak-coupling limit the energy gain is quadratic in $J$,
while the Kondo temperature is exponentially small. The exact relation between
the two quantities depends on the detailed form of the density of states of the
band. In the limit of low electron density the Kondo screening is affected by
the strong particle-hole asymmetry due to the presence of the band-edge van
Hove singularities. We consider the cases of 1D, 2D, and 3D tight-binding
lattices with inverse-square-root, step function, and square-root onsets of the
density of states that are characteristic of the respective dimensionalities.
We always find two different regimes depending on whether $T_K$ is higher or
lower than $\mu$, the chemical potential measured from the bottom of the band.
For 2D and 3D, we find a sigmoidal cross-over between the large-$J$ and
small-$J$ asymptotics in $\Delta E$, and a clear separation between $\Delta E$
and $T_K$ for $T_K < \mu$. For 1D, there is in addition a sizable
intermediate-$J$ regime where the Kondo temperature is quadratic in $J$ due to
the diverging density of states at the band edge. Furthermore, we find that in
1D the particle-hole asymmetry leads to a large decrease of $T_K$ compared to
the standard result obtained by approximating the density of states to be
constant (flat-band approximation), while in 3D the opposite is the case; this
is due to the non-trivial interplay of the exchange and potential scattering
renormalization in the presence of particle-hole asymmetry.


title: Uncertainty quantification for the horseshoe

abstract:
  We investigate the credible sets and marginal credible intervals resulting
from the horseshoe prior in the sparse multivariate normal means model. We do
so in an adaptive setting without assuming knowledge of the sparsity level
(number of signals). We consider both the hierarchical Bayes method of putting
a prior on the unknown sparsity level and the empirical Bayes method with the
sparsity level estimated by maximum marginal likelihood. We show that credible
balls and marginal credible intervals have good frequentist coverage and
optimal size if the sparsity level of the prior is set correctly. By general
theory honest confidence sets cannot adapt in size to an unknown sparsity
level. Accordingly the hierarchical and empirical Bayes credible sets based on
the horseshoe prior are not honest over the full parameter space. We show that
this is due to over-shrinkage for certain parameters and characterise the set
of parameters for which credible balls and marginal credible intervals do give
correct uncertainty quantification. In particular we show that the fraction of
false discoveries by the marginal Bayesian procedure is controlled by a correct
choice of cut-off.


title: Embracing Agile methodology during DevOps Developer Internship Program

abstract:
  The DevOps team adopted agile methodologies during the summer internship
program as an initiative to move away from waterfall. The DevOps team
implemented the Scrum software development strategy to create an internal data
dictionary web application. This article reports on the transition process and
lessons learned from the pilot program.


title:
First results of the Kourovka Planet Search: discovery of transiting
  exoplanet candidates in the first three target fields

abstract:
  We present the first results of our search for transiting exoplanet
candidates as part of the Kourovka Planet Search (KPS) project. The primary
objective of the project is to search for new hot Jupiters which transit their
host stars, mainly in the Galactic plane, in the $R_c$ magnitude range of 11 to
14 mag. Our observations were performed with the telescope of the MASTER
robotic network, installed at the Kourovka astronomical observatory of the Ural
Federal University (Russia), and the Rowe-Ackermann Schmidt Astrograph,
installed at the private Acton Sky Portal Observatory (USA). As test
observations, we observed three celestial fields of size $2\times2$ deg$^2$
during the period from 2012 to 2015. As a result, we discovered four transiting
exoplanet candidates among the 39000 stars of the input catalogue. In this
paper, we provide the description of the project and analyse additional
photometric, spectral, and speckle interferometric observations of the
discovered transiting exoplanet candidates. Three of the four transiting
exoplanet candidates are most likely astrophysical false positives, while the
nature of the fourth (most promising) candidate remains to be ascertained.
Also, we propose an alternative observing strategy that could increase the
project's exoplanet haul.


title:
Random Walk Graph Laplacian based Smoothness Prior for Soft Decoding of
  JPEG Images

abstract:
  Given the prevalence of JPEG compressed images, optimizing image
reconstruction from the compressed format remains an important problem. Instead
of simply reconstructing a pixel block from the centers of indexed DCT
coefficient quantization bins (hard decoding), soft decoding reconstructs a
block by selecting appropriate coefficient values within the indexed bins with
the help of signal priors. The challenge thus lies in how to define suitable
priors and apply them effectively.
  In this paper, we combine three image priors---Laplacian prior for DCT
coefficients, sparsity prior and graph-signal smoothness prior for image
patches---to construct an efficient JPEG soft decoding algorithm. Specifically,
we first use the Laplacian prior to compute a minimum mean square error (MMSE)
initial solution for each code block. Next, we show that while the sparsity
prior can reduce block artifacts, limiting the size of the over-complete
dictionary (to lower computation) would lead to poor recovery of high DCT
frequencies. To alleviate this problem, we design a new graph-signal smoothness
prior (desired signal has mainly low graph frequencies) based on the left
eigenvectors of the random walk graph Laplacian matrix (LERaG). Compared to
previous graph-signal smoothness priors, LERaG has desirable image filtering
properties with low computation overhead. We demonstrate how LERaG can
facilitate recovery of high DCT frequencies of a piecewise smooth (PWS) signal
via an interpretation of low graph frequency components as relaxed solutions to
normalized cut in spectral clustering. Finally, we construct a soft decoding
algorithm using the three signal priors with appropriate prior weights.
Experimental results show that our proposal outperforms state-of-the-art soft
decoding algorithms in both objective and subjective evaluations noticeably.


title: Cell-Edge-Aware Precoding for Downlink Massive MIMO Cellular Networks

abstract:
  We propose a cell-edge-aware (CEA) zero forcing (ZF) precoder that exploits
the excess spatial degrees of freedom provided by a large number of base
station (BS) antennas to suppress inter-cell interference at the most
vulnerable user equipments (UEs). We evaluate the downlink performance of
CEA-ZF, as well as that of a conventional cell-edge-unaware (CEU) ZF precoder
in a network with random base station topology. Our analysis and simulations
show that the proposed CEA-ZF precoder outperforms CEU-ZF precoding in terms of
(i) aggregate per-cell data rate, (ii) coverage probability, and (iii)
95%-likely, or edge user, rate. In particular, when both perfect channel state
information and a large number of antennas N are available at the BSs, we
demonstrate that the outage probability under CEA-ZF and CEU-ZF decay as 1/N^2
and 1/N, respectively. This result identifies CEA-ZF as a more effective
precoding scheme for massive MIMO cellular networks. Our framework also reveals
the importance of scheduling the optimal number of UEs per BS, and confirms the
necessity to control the amount of pilot contamination received during the
channel estimation phase.


title: Isospectral nearly K\"ahler manifolds

abstract:
  We give a systematic way to construct almost conjugate pairs of finite
subgroups of $Spin(2n+1)$ and $Pin(n)$ for $n\in \mathbb{N}$ sufficiently
large. As a geometric application, we give an infinite family of pairs
$M_1^{d_n}$ and $M_2^{d_n}$ of nearly K\"ahler manifolds that are isospectral
for the Dirac and Laplace operator with increasing dimensions $d_n>6$. We
provide additionally a computation of the volume of (locally) homogeneous six
dimensional nearly K\"ahler manifolds and investigate the existence of Sunada
pairs in this dimension.


title: The ZEUS long term data preservation project

abstract:
  The ZEUS data preservation (ZEUS DP) project assures continued access to the
data and documentation related to the experiment. It aims to provide the
ability to continue the generation of valuable scientific results from these
data in the future. This talk presents analysis opportunities within the ZEUS
DP project and its benefits for the physics community. The implications of the
preserved data are discussed in the context of current data analyses,
verification of contemporary and future theoretical models and the planning of
future experiments and analyses. The detailed documentation on the data
preservation effort can serve as an example for the data preservation efforts
in current and future experiments.


title:
Generalized weak-binding relations of compositeness in effective field
  theory

abstract:
  We study the compositeness of near-threshold states to investigate the
internal structure of exotic hadron candidates. Within the framework of
effective field theory, Weinberg's weak-binding relation is extended to more
general cases by easing several preconditions. First, by evaluating the
contribution from the decay channel, we obtain the generalized relation for
unstable quasibound states. Next, we generalize the relation to include the
nearby CDD (Castillejo-Dalitz-Dyson) pole contribution with the help of the
Pade approximant. The validity of the estimation with the generalized
weak-binding relations is examined by numerical calculations. The method to
systematically evaluate the error in the weak-binding relation is presented.
Finally, by applying the extended relation to Lambda(1405), f0(980) and
a0(980), we discuss their internal structure, in comparison with other
approaches.


title:
Orbital-selective Mott phase of Cu-substituted iron-based
  Superconductors

abstract:
  We study the phase transition in Cu-substituted iron-based superconductors
with a new developed real-space Green's function method. We find that Cu
substitution has strong effect on the orbital-selective Mott transition
introduced by the Hund's rule coupling. The redistribution of the orbital
occupancy which is caused by the increase of the Hund's rule coupling, gives
rise to the Mott-Hubbard metal-insulator transition in the half-filled $d_{xy}$
orbital. We also find that more and more electronic states appear inside that
Mott gap of the $d_{xy}$ orbital with the increase of Cu substitution, and the
in-gap states around the Fermi level are strongly localized at some specific
lattice sites. Further, a distinctive phase diagram, obtained for the
Cu-substituted Fe-based superconductors, displays an orbital-selective
insulating phase, as a result of the cooperative effect of the Hund's rule
coupling and the impurity-induced disorder.


title: Thermal imaging of spin Peltier effect

abstract:
  When a charge current is applied to a junction comprising two different
conductors, its temperature increases or decreases depending on the direction
of the charge current. This phenomenon is called the Peltier effect, which is
used in solid-state heat pumps and temperature controllers in electronics.
Recently, in spintronics, a spin counterpart of the Peltier effect was
observed. The "spin Peltier effect" modulates the temperature of a magnetic
junction depending on the direction of a spin current. Here we report thermal
imaging of the spin Peltier effect; using active thermography technique, we
visualize the temperature modulation induced by a spin current injected into a
magnetic insulator from an adjacent metal. The thermal images reveal
characteristic distribution of spin-current-induced heat sources, resulting in
the temperature change confined only in the vicinity of the metal/insulator
interface. The finding of this anomalous temperature distribution allows us to
estimate the actual magnitude of the temperature modulation induced by the spin
Peltier effect, which is found to be more than one order of magnitude greater
than that previously believed.


title:
On optimal joint reflective and refractive dividend strategies in
  spectrally positive L\'evy models

abstract:
  The expected present value of dividends is one of the classical stability
criteria in actuarial risk theory. In this context, numerous papers considered
threshold (refractive) and barrier (reflective) dividend strategies. These were
shown to be optimal in a number of different contexts for bounded and unbounded
payout rates, respectively. In this paper, motivated by the behaviour of some
dividend paying stock exchange companies, we determine the optimal dividend
strategy when both continuous (refractive) and lump sum (reflective) dividends
can be paid at any time, and if they are subject to different transaction
rates. We consider the general family of spectrally positive L\'evy processes.
Using scale functions, we obtain explicit formulas for the expected present
value of dividends until ruin, with a penalty at ruin. We develop a
verification lemma, and show that a two-layer (a,b) strategy is optimal. Such a
strategy pays continuous dividends when the surplus exceeds level a>0, and all
of the excess over b>a as lump sum dividend payments. Results are illustrated.


title: Long cycles have the edge-Erd\H{o}s-P\'osa property

abstract:
  We prove that the set of long cycles has the edge-Erd\H{o}s-P\'osa property:
for every fixed integer $\ell\ge 3$ and every $k\in\mathbb{N}$, every graph $G$
either contains $k$ edge-disjoint cycles of length at least $\ell$ (long
cycles) or an edge set $X$ of size $O(k^2\log k + \ell k)$ such that $G-X$ does
not contain any long cycle. This answers a question of Birmel\'e, Bondy, and
Reed (Combinatorica 27 (2007), 135--145).


title:
Bayesian inverse problems with $l_1$ priors: a Randomize-then-Optimize
  approach

abstract:
  Prior distributions for Bayesian inference that rely on the $l_1$-norm of the
parameters are of considerable interest, in part because they promote parameter
fields with less regularity than Gaussian priors (e.g., discontinuities and
blockiness). These $l_1$-type priors include the total variation (TV) prior and
the Besov $B^s_{1,1}$ space prior, and in general yield non-Gaussian posterior
distributions. Sampling from these posteriors is challenging, particularly in
the inverse problem setting where the parameter space is high-dimensional and
the forward problem may be nonlinear. This paper extends the
randomize-then-optimize (RTO) method, an optimization-based sampling algorithm
developed for Bayesian inverse problems with Gaussian priors, to inverse
problems with $l_1$-type priors. We use a variable transformation to convert an
$l_1$-type prior to a standard Gaussian prior, such that the posterior
distribution of the transformed parameters is amenable to Metropolized sampling
via RTO. We demonstrate this approach on several deconvolution problems and an
elliptic PDE inverse problem, using TV or Besov $B^s_{1,1}$ space priors. Our
results show that the transformed RTO algorithm characterizes the correct
posterior distribution and can be more efficient than other sampling
algorithms. The variable transformation can also be extended to other
non-Gaussian priors.


title:
502 Gbits/s Quantum Random Number Generation with Simple and Compact
  Structure

abstract:
  We propose and implement a simple and compact quantum random number
generation (QRNG) scheme based on the quantum phase fluctuations of a DFB
laser. The distribution probability of the experimentally measured data fits
well with the simulation result, got from the theoretical model we established.
Min-entropy estimation and Toeplitz-hashing randomness extractor are used to
obtain the final random bit. The proposed approach has advantages not only in
simple structure but also in high random bit generation rate. As a result, 502
Gbits/s random bits generation speed can be obtained, which is much higher than
previous similar schemes. This approach offers a possibility to promote the
practical application of QRNG.