title:
Identification of criticality in neuronal avalanches: II. A theoretical
  and empirical investigation of the driven case

abstract:
  The observation of apparent power-laws in neuronal systems has led to the
suggestion that the brain is at, or close to, a critical state and may be a
self-organised critical system. Within the framework of self-organised
criticality a separation of timescales is thought to be crucial for the
observation of power-law dynamics and computational models are often
constructed with this property. However, this is not necessarily a
characteristic of physiological neural networks - external input does not only
occur when the network is at rest/a steady state. In this paper we study a
simple neuronal network model driven by a continuous external input (i.e.\ the
model does not have a separation of timescales) and analytically tuned to
operate in the region of a critical state (it reaches the critical regime
exactly in the absence of input - the case studied in the companion paper to
this article). The system displays avalanche dynamics in the form of cascades
of neuronal firing separated by periods of silence. We observe partial
scale-free behaviour in the distribution of avalanche size for low levels of
external input. We analytically derive the distributions of waiting times and
investigate their temporal behaviour in relation to different levels of
external input, showing that the system's dynamics can exhibit partial
long-range temporal correlations. We further show that as the system approaches
the critical state by two alternative `routes', different markers of
criticality (partial scale-free behaviour and long-range temporal correlations)
are displayed. This suggests that signatures of criticality exhibited by a
particular system in close proximity to a critical state are dependent on the
region in parameter space at which the system (currently) resides.


title: The lateral shower age parameter as an estimator of chemical composition

abstract:
  We explore the feasibility of estimating primary cosmic ray composition at
ultra high energies from the study of lateral age parameter of Extensive Air
Showers (EAS) at ground level. Using different types of lateral distribution
functions, we fit the particle density of simulated EAS to find the lateral age
parameter. We discuss the chemical composition calculating the merit factor for
each parameter distribution. The analysis considers three different primary
particles (proton, iron and gamma), four different zenith angles (0{\deg},
15{\deg}, 30{\deg} and 45{\deg}) and three primary energies (10^{17.25} eV,
10^{17.50} eV and 10^{17.75} eV).


title: Self-healing Dynamics of Surfactant Coatings on Thin Viscous Films

abstract:
  We investigate the dynamics of an insoluble surfactant on the surface of a
thin viscous fluid spreading inward to fill a surfactant-free region. During
the initial stages of surfactant self-healing, Marangoni forces drive an
axisymmetric ridge inward to coalesce into a growing central distension; this
is unlike outward-spreading, in which the ridge decays. In later dynamics, the
distension slowly decays and the surfactant concentration equilibrates. We
present results from experiments in which we simultaneously measure the
surfactant concentration (using fluorescently-tagged lipids) and the fluid
height profile (via laser profilometry). We compare the results to simulations
of a mathematical model using parameters from our experiments. For surfactant
concentrations close to but below the critical monolayer concentration, we
observe agreement between the height profiles in the numerical simulations and
the experiment, but disagreement in the surfactant distribution. In experiments
at lower concentrations, the surfactant spreading and formation of a Marangoni
ridge are no longer present, and a persistent lipid-free region remains. This
observation, which is not captured by the simulations, has undesirable
implications for applications where uniform coverage is advantageous. Finally,
we probe the generality of the effect, and find that distensions of similar
size are produced independent of initial fluid thickness, size of initial clean
region, and surfactant type.


title: Coherent Emission in Fast Radio Bursts

abstract:
  The fast (ms) radio bursts reported by Thornton, {\it et al.} have extremely
high brightness temperatures if at the inferred cosmological distances. This
implies coherent emission by "bunches" of charges. We model the emission region
as a screen of dipole radiators resonant at the frequency of observation and
calculate the necessary charge bunching. From this we infer the minimum
electron energy required to overcome electrostatic repulsion. The FRB, like the
giant pulses of the Crab pulsar, display banded spectra that may be harmonics
of plasma frequency emission by plasma turbulence. If FRB are the counterparts
of comparatively frequent Galactic events, these may be detected by radio
telescopes in their far sidelobes or by small arrays of dipoles.

categories: astro-ph.HE astro-ph.CO astro-ph.IM physics.ins-det


title:
On the model companion of partial differential fields with an
  automorphism

abstract:
  We prove that the class of partial differential fields of characteristic zero
with an automorphism has a model companion. We then establish the basic model
theoretic properties of this theory and prove that it satisfies the Zilber
dichotomy for finite dimensional minimal types.


title: The equitable Racah algebra from three su(1,1) algebras

abstract:
  The Racah algebra, a quadratic algebra with two independent generators, is
central in the analysis of superintegrable models and encodes the properties of
the Racah polynomials. It is the algebraic structure behind the su(1,1) Racah
problem as it is realized by the intermediate Casimir operators arising in the
addition of three irreducible su(1,1) representations. It has been shown that
this Racah algebra can also be obtained from quadratic elements in the
enveloping algebra of su(2). The correspondence between these two realizations
is here explained and made explicit.


title: White Paper on DOE-HEP Accelerator Modeling Science Activities

abstract:
  Toward the goal of maximizing the impact of computer modeling on the design
of future particle accelerators and the development of new accelerator
techniques & technologies, this white paper presents the rationale for: (a)
strengthening and expanding programmatic activities in accelerator modeling
science within the Department of Energy (DOE) Office of High Energy Physics
(HEP) and (b) increasing the community-wide coordination and integration of
code development.


title:
Advanced sine wave modulation of continuous wave laser system for
  atmospheric CO2 differential absorption measurements

abstract:
  In this theoretical study, modulation techniques are developed to support the
Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS)
mission. A CW lidar system using sine waves modulated by ML pseudo random noise
codes is described for making simultaneous online/offline differential
absorption measurements. Amplitude and Phase Shift Keying (PSK) modulated IM
carriers, in addition to a hybrid pulse technique are investigated that exhibit
optimal autocorrelation properties. A method is presented to bandwidth limit
the ML sequence based on a filter implemented in terms of Jacobi theta
functions that does not significantly degrade the resolution or introduce side
lobes as a means of reducing aliasing and IM carrier bandwidth.


title:
Constraining nova observables: direct measurements of resonance
  strengths in 33S(p,\gamma)34Cl

abstract:
  The 33S(p,\gamma)34Cl reaction is important for constraining predictions of
certain isotopic abundances in oxygen-neon novae. Models currently predict as
much as 150 times the solar abundance of 33S in oxygen-neon nova ejecta. This
overproduction factor may, however, vary by orders of magnitude due to
uncertainties in the 33S(p,\gamma)34Cl reaction rate at nova peak temperatures.
Depending on this rate, 33S could potentially be used as a diagnostic tool for
classifying certain types of presolar grains. Better knowledge of the
33S(p,\gamma)34Cl rate would also aid in interpreting nova observations over
the S-Ca mass region and contribute to the firm establishment of the maximum
endpoint of nova nucleosynthesis. Additionally, the total S elemental abundance
which is affected by this reaction has been proposed as a thermometer to study
the peak temperatures of novae. Previously, the 33S(p,\gamma)34Cl reaction rate
had only been studied directly down to resonance energies of 432 keV. However,
for nova peak temperatures of 0.2-0.4 GK there are 7 known states in 34Cl both
below the 432 keV resonance and within the Gamow window that could play a
dominant role. Direct measurements of the resonance strengths of these states
were performed using the DRAGON recoil separator at TRIUMF. Additionally two
new states within this energy region are reported. Several hydrodynamic
simulations have been performed, using all available experimental information
for the 33S(p,\gamma)34Cl rate, to explore the impact of the remaining
uncertainty in this rate on nucleosynthesis in nova explosions. These
calculations give a range of ~ 20-150 for the expected 33S overproduction
factor, and a range of ~ 100-450 for the 32S/33S ratio expected in ONe novae.


title: Long-Time Mean Square Displacements in Proteins

abstract:
  We propose a method for obtaining the intrinsic, long time mean square
displacement (MSD) of atoms and molecules in proteins from finite time
molecular dynamics (MD) simulations. Typical data from simulations are limited
to times of 1 to 10 ns and over this time period the calculated MSD continues
to increase without a clear limiting value. The proposed method consists of
fitting a model to MD simulation-derived values of the incoherent intermediate
neutron scattering function, $I_{inc}(Q,t)$, for finite times. The infinite
time MSD, $<r^2>$, appears as a parameter in the model and is determined by
fits of the model to the finite time $I_{inc}(Q,t)$. Specifically, the $<r^2>$
is defined in the usual way in terms of the Debye-Waller factor as $I(Q,t =
\infty) = \exp(- Q^2 <r^2 > /3)$. The method is illustrated by obtaining the
intrinsic MSD $<r^2>$ of hydrated lysozyme powder (h = 0.4 g water/g protein)
over a wide temperature range. The intrinsic $<r^2>$ obtained from data out to
1 ns and to 10 ns is found to be the same. The intrinsic $<r^2>$ is
approximately twice the value of the MSD that is reached in simulations after
times of 1 ns which correspond to those observed using neutron instruments that
have an energy resolution width of 1 \mu eV.


title: Improved Parallel Algorithms for Spanners and Hopsets

abstract:
  We use exponential start time clustering to design faster and more
work-efficient parallel graph algorithms involving distances. Previous
algorithms usually rely on graph decomposition routines with strict
restrictions on the diameters of the decomposed pieces. We weaken these bounds
in favor of stronger local probabilistic guarantees. This allows more direct
analyses of the overall process, giving: * Linear work parallel algorithms that
construct spanners with $O(k)$ stretch and size $O(n^{1+1/k})$ in unweighted
graphs, and size $O(n^{1+1/k} \log k)$ in weighted graphs. * Hopsets that lead
to the first parallel algorithm for approximating shortest paths in undirected
graphs with $O(m\;\mathrm{polylog}\;n)$ work.


title: On Determining Deep Holes of Generalized Reed-Solomon Codes

abstract:
  For a linear code, deep holes are defined to be vectors that are further away
from codewords than all other vectors. The problem of deciding whether a
received word is a deep hole for generalized Reed-Solomon codes is proved to be
co-NP-complete. For the extended Reed-Solomon codes $RS_q(\F_q,k)$, a
conjecture was made to classify deep holes by Cheng and Murray in 2007. Since
then a lot of effort has been made to prove the conjecture, or its various
forms. In this paper, we classify deep holes completely for generalized
Reed-Solomon codes $RS_p (D,k)$, where $p$ is a prime, $|D| > k \geqslant
\frac{p-1}{2}$. Our techniques are built on the idea of deep hole trees, and
several results concerning the Erd{\"o}s-Heilbronn conjecture.


title:
Mean-field and direct numerical simulations of magnetic flux
  concentrations from vertical field

abstract:
  Strongly stratified hydromagnetic turbulence has previously been found to
produce magnetic flux concentrations if the domain is large enough compared
with the size of turbulent eddies. Mean-field simulations (MFS) using
parameterizations of the Reynolds and Maxwell stresses show a negative
effective magnetic pressure instability and have been able to reproduce many
aspects of direct numerical simulations (DNS) regarding the growth rate of this
large-scale instability, shape of the resulting magnetic structures, and their
height as a function of magnetic field strength. Unlike the case of an imposed
horizontal field, for a vertical one, magnetic flux concentrations of
equipartition strength with the turbulence can be reached. This results in
magnetic spots that are reminiscent of sunspots. Here we want to find out under
what conditions magnetic flux concentrations with vertical field occur and what
their internal structure is. We use a combination of MFS, DNS, and implicit
large-eddy simulations to characterize the resulting magnetic flux
concentrations in forced isothermal turbulence with an imposed vertical
magnetic field. We confirm earlier results that in the kinematic stage of the
large-scale instability the horizontal wavelength of structures is about 10
times the density scale height. At later times, even larger structures are
being produced in a fashion similar to inverse spectral transfer in helically
driven turbulence. Using turbulence simulations, we find that magnetic flux
concentrations occur for different values of the Mach number between 0.1 and
0.7. DNS and MFS show magnetic flux tubes with mean-field energies comparable
to the turbulent kinetic energy. The resulting vertical magnetic flux tubes are
being confined by downflows along the tubes and corresponding inflow from the
sides, which keep the field concentrated.


title:
Dimerization-Induced Cross-Layer Quasi-Two-Dimensionality in Metallic
  Iridate IrTe2

abstract:
  The crystal structure of layered metal IrTe2 is determined using
single-crystal x-ray diffraction. At T=220 K, it exhibits Ir and Te dimers
forming a valence-bond crystal. Electronic structure calculations reveal an
intriguing quasi-two-dimensional electronic state, with planes of reduced
density of states cutting diagonally through the Ir and Te layers. These planes
are formed by the Ir and Te dimers, which exhibit a signature of covalent
bonding character development. Evidence for significant charge
disproportionation among the dimerized and non-dimerized Ir (charge order) is
also presented.


title: Summary of the Nobel Symposium on LHC Results

abstract:
  This is a personal summary of points made during, and arising from the
symposium, drawing largely from the talks presented there. The Standard Model
is doing fine, including QCD, the electroweak sector and flavour physics. The
good news is that a Standard-Model-like Higgs boson has appeared with the
predicted mass, but the bad news is that the LHC has provided no hint of other
new physics. On the other hand, physics beyond the Standard Model is needed to
explain neutrino masses and mixing, and we look forward to experiments
revealing their mass hierarchy and CP violation. Cosmology and astrophysics
also require new physics to explain the origin of matter, dark matter, dark
energy and the CMB fluctuations. I still think that supersymmetry is the
best-motivated extension of the Standard Model, and look forward to the next
phases of LHC operation at higher energy and luminosity. In the mean time,
ideas abound for a new accelerator to study the Higgs boson in detail and/or
whatever else the LHC may reveal in its next run.


title:
Unital Dilations of Completely Positive Semigroups: From Combinatorics
  to Continuity

abstract:
  Using ideas due to Jean-Luc Sauvageot, we prove the existence of a continuous
unital dilation of a CP$_0$-semigroup on a separable W$^*$-algebra. This paper
presents the material in the author's Ph. D. thesis (arXiv.org:1304.0134.pdf)
with some generalizations and an improved exposition.


title: Tropical Amplitudes

abstract:
  In this work, we argue that the $\alpha'\to 0$ limit of closed string theory
scattering amplitudes is a tropical limit. The motivation is to develop a
technology to systematize the extraction of Feynman graphs from string theory
amplitudes at higher genus. An important technical input from tropical geometry
is the use of tropical theta functions with characteristics to rigorously
derive the worldline limit of the worldsheet propagator. This enables us to
perform a non-trivial computation at two loops: we derive the tropical form of
the integrand of the genus-two four-graviton type II string amplitude, which
matches the direct field theory computations. At the mathematical level, this
limit is an implementation of the correspondence between the moduli space of
Riemann surfaces and the tropical moduli space.


title: Differential cross sections for top-pair and single-top production

abstract:
  I present higher-order results, based on NNLL resummation, for differential
transverse momentum and rapidity distributions in processes involving top
quarks. In particular results are presented for top-pair production and for
single-top production in different channels.


title: The modular action on PSL(2,R)-characters in genus 2

abstract:
  We explore the dynamics of the action of the mapping class group in genus 2
on the PSL(2,R)-character variety. We prove that this action is ergodic on the
connected components of Euler class 1 and -1, as it was conjectured by Goldman.
In the connected component of Euler class 0 there are two invariant open
subsets, on one of them the action is ergodic. In this process we give a
partial answer to a question of Bowditch.


title: Horospherical limit points of locally symmetric spaces

abstract:
  Suppose X/Gamma is an arithmetic locally symmetric space of noncompact type
(with the natural metric induced by the Killing form of the isometry group of
X), and let p be a point on the visual boundary of X. It was shown by T.Hattori
that if each horoball based at p intersects every Gamma-orbit in X, then p is
not on the boundary of any Q-split flat in X (where Q is the field of rational
numbers). We prove the converse. (This was conjectured by W.H.Rehn in some
special cases.) Furthermore, we prove an analogous result when Gamma is a
nonarithmetic lattice.


title: Entanglement sudden-death time: a geometric quantity

abstract:
  We study the entanglement evolution of the set of Bell diagonal states for a
two-qubit system coupled to two independent vacuum noise sources. This set can
be represented geometrically as the set of points inside a tetrahedron in a
three-dimensional Euclidean space and contains the maximally entangled states
for bipartite systems. We show that the set of entangled Bell diagonal states
can be divided into two bounded subsets in this representation: states that
evolve into separable states in a finite time and states that lose their
entanglement asymptotically. Additionally, we find that the finite time in
which the Bell diagonal states lose their entanglement depends only on the
distances from their position in the three-dimensional representation to the
boundaries of both, the set of separable states and the set of states that
remains always entangled.


title:
Two-Nucleon Systems in a Finite Volume: (II) 3S1-3D1 Coupled Channels
  and the Deuteron

abstract:
  The energy spectra of two nucleons in a cubic volume provide access to the
two phase shifts and one mixing angle that define the S-matrix in the 3S1-3D1
coupled channels containing the deuteron. With the aid of recently derived
energy quantization conditions for such systems, and the known scattering
parameters, these spectra are predicted for a range of volumes. It is found
that extractions of the infinite-volume deuteron binding energy and leading
scattering parameters, including the S-D mixing angle at the deuteron pole, are
possible from Lattice QCD calculations of two-nucleon systems with boosts of
|P| <= 2pi sqrt{3}/L in volumes with 10 fm <~ L <~ 14 fm. The viability of
extracting the asymptotic D/S ratio of the deuteron wavefunction from Lattice
QCD calculations is discussed.


title: Single-Field Consistency Relations of Large Scale Structure

abstract:
  We derive consistency relations for the late universe (CDM and \Lambda CDM):
relations between an n-point function of the density contrast \delta and an
(n+1)-point function in the limit in which one of the (n+1) momenta becomes
much smaller than the others. These are based on the observation that a long
mode, in single-field models of inflation, reduces to a diffeomorphism since
its freezing during inflation all the way until the late universe, even when
the long mode is inside the horizon (but out of the sound horizon). These
results are derived in Newtonian gauge, at first and second order in the small
momentum q of the long mode and they are valid non-perturbatively in the
short-scale \delta. In the non-relativistic limit our results match with
(Kehagias and Riotto '13) and (Peloso and Pietroni '13). These relations are a
consequence of diffeomorphism invariance; they are not satisfied in the
presence of extra degrees of freedom during inflation or violation of the
Equivalence Principle (extra forces) in the late universe.


title:
On the (non)existence of symplectic resolutions for imprimitive
  symplectic reflection groups

abstract:
  We study the existence of symplectic resolutions of quotient singularities
V/G where V is a symplectic vector space and G acts symplectically. Namely, we
classify the symplectically irreducible and imprimitive groups, excluding those
of the form $K \rtimes S_2$ where $K < \SL_2(\C)$, for which the corresponding
quotient singularity admits a projective symplectic resolution. As a
consequence, for $\dim V \neq 4$, we classify all quotient singularities $V/G$
admitting a projective symplectic resolution which do not decompose as a
product of smaller-dimensional quotient singularities, except for at most four
explicit singularities, that occur in dimensions at most 10, for whom the
question of existence remains open.


title:
The Mid-infrared Emission of Narrow-Line Active Galactic Nuclei:
  Star-Formation, Nuclear Activity and two populations revealed by WISE

abstract:
  We explore the nature of the long-wavelength mid-infrared (MIR) emission of a
sample of 13000 local Type II (narrow-line) Active Galactic Nuclei (AGNs) from
the Sloan Digital Sky Survey (SDSS) using 12 and 22 micron photometry from the
WISE all-sky survey. In combination with FIRST 1.4 GHz measurements, we show
that AGNs divide into two relatively distinct populations or "branches" in the
plane of MIR and radio luminosity. Seyfert galaxies lie almost exclusively on a
MIR-bright branch (Branch A), while low-ionization nuclear emission line
galaxies (LINERs) are split evenly into Branch A and the MIR-faint Branch B. We
devise various tests to constrain the processes that define the branches,
including a comparison to the properties of pure star-forming (SF) inactive
galaxies on the MIR-Radio plane. We demonstrate that the total MIR emission of
objects on Branch A, including most Seyfert galaxies, is governed primarily by
host star-formation, with about 15% of the 22 micron luminosity coming from
AGN-heated dust. This implies that on-going dusty star-formation is a general
property of Seyfert host galaxies. We show that the 12 micron broad-band
luminosity of AGNs on Branch A is suppressed with respect to star-forming
galaxies, possibly due to the destruction of PAHs or deeper 10 microns Si
absorption in AGNs. We uncover a correlation between the MIR luminosity and [O
III] luminosity in AGNs. This suggests a relationship between the SFR and
nuclear luminosity in the AGN population, but we caution on the importance of
selection effects inherent to such AGN-dominated emission-line galaxies in
driving such a correlation. We highlight the MIR-radio plane as a useful tool
in comparative studies of SF and nuclear activity in AGN.


title:
The Complete Two-Loop Integrated Jet Thrust Distribution In
  Soft-Collinear Effective Theory

abstract:
  In this work, we complete the calculation of the soft part of the two-loop
integrated jet thrust distribution in e+e- annihilation. This jet mass
observable is based on the thrust cone jet algorithm, which involves a veto
scale for out-of-jet radiation. The previously uncomputed part of our result
depends in a complicated way on the jet cone size, r, and at intermediate
stages of the calculation we actually encounter a new class of multiple
polylogarithms. We employ an extension of the coproduct calculus to
systematically exploit functional relations and represent our results
concisely. In contrast to the individual contributions, the sum of all global
terms can be expressed in terms of classical polylogarithms. Our explicit
two-loop calculation enables us to clarify the small r picture discussed in
earlier work. In particular, we show that the resummation of the logarithms of
r that appear in the previously uncomputed part of the two-loop integrated jet
thrust distribution is inextricably linked to the resummation of the non-global
logarithms. Furthermore, we find that the logarithms of r which cannot be
absorbed into the non-global logarithms in the way advocated in earlier work
have coefficients fixed by the two-loop cusp anomalous dimension. We also show
that, given appropriate L-loop contributions to the integrated hemisphere soft
function, one can straightforwardly predict a number of potentially large
logarithmic contributions at L loops not controlled by the factorization
theorem for jet thrust.


title: Constraining Higgs mediated dark matter interactions

abstract:
  We perform an analysis of Higgs portal models of dark matter (DM), where DM
is light enough to contribute to invisible Higgs decays. Using effective field
theory we show that DM can be a thermal relic only if there are additional
light particles present with masses below a few 100 GeV. We give three concrete
examples of viable Higgs portal models of light DM: (i) the SM extended by DM
scalar along with an electroweak triplet and a singlet, (ii) a Two Higgs
Doublet Model of type II with additional scalar DM, (iii) SM with DM and an
extra scalar singlet that is lighter than DM. In all three examples the Br(h to
invisible) constraint is not too restrictive, because it is governed by
different parameters than the relic abundance. Additional light particles can
have implications for flavor violation and collider searches.


title:
The Aquarius Co-Moving Group is Not a Disrupted Classical Globular
  Cluster

abstract:
  We present a detailed analysis of high-resolution, high S/N spectra for 5
Aquarius stream stars observed with the MIKE spectrograph on the Magellan Clay
telescope. Our sample represents one third of the 15 known members in the
stream. We find the stream is not mono-metallic: the metallicity ranges from
[Fe/H] = -0.63 to -1.58. No anti-correlation in Na-O abundances is present, and
we find a strong positive Mg-Al relationship, similar to that observed in the
thick disk. We find no evidence that the stream is a result of a disrupted
classical globular cluster, contrary to a previously published claim. High
[(Na, Ni, alpha)/Fe] and low [Ba/Y] abundance ratios in the stream suggests it
is not a tidal tail from a disrupted dwarf galaxy, either. The stream is
chemically indistinguishable from Milky Way field stars with the exception of
one candidate, C222531-145437. From its position, velocity, and detailed
chemical abundances, C222531-145437 is likely a star that was tidally disrupted
from omega-Centauri. We propose the Aquarius stream is Galactic in origin, and
could be the result from a disk-satellite perturbation in the Milky Way thick
disk on the order of a few Gyr ago: derived orbits, UVW velocities, and angular
momenta of the Aquarius members offer qualitative support for our hypothesis.
Assuming C222531-145437 is a tidally disrupted member of omega-Centauri, this
system is the most likely disk perturber. In the absence of compelling chemical
and/or dynamical evidence that the Aquarius stream is the tidal tail of a
disrupted satellite, we advocate the "Aquarius group" as a more appropriate
description. Like the Canis Major over-density, as well as the Hercules and
Monoceros groups, the Aquarius group joins the list of kinematically-identified
substructures that are not actually accreted material: they are simply part of
the rich complexity of the Milky Way structure.


title:
Hunting the Parent of the Orphan Stream II: The First High-Resolution
  Spectroscopic Study

abstract:
  We present the first high-resolution spectroscopic study on the Orphan Stream
for five stream candidates, observed with the Magellan Inamori Kyocera Echelle
(MIKE) spectrograph on the Magellan Clay telescope. The targets were selected
from the low-resolution catalog of Casey et al (2013a): 3 high-probability
members, 1 medium and 1 low-probability stream candidate were observed. Our
analysis indicates the low and medium-probability target are metal-rich field
stars. The remaining three high-probability targets range over $\sim$1 dex in
metallicity, and are chemically distinct compared to the other 2 targets and
all standard stars: low [$\alpha$/Fe] abundance ratios are observed, and lower
limits are ascertained for [Ba/Y], which sit well above the Milky Way trend.
These chemical signatures demonstrate that the undiscovered parent system is
unequivocally a dwarf spheroidal galaxy, consistent with dynamical constraints
inferred from the stream width and arc. As such, we firmly exclude the proposed
association between NGC 2419 and the Orphan stream. A wide range in
metallicities adds to the similarities between the Orphan stream and Segue 1,
although low [$\alpha$/Fe] abundance ratios in the Orphan stream are in tension
with high [$\alpha$/Fe] values observed in Segue 1. Open questions remain
before Segue 1 could possibly be claimed as the `parent' of the Orphan stream.
The parent system could well remain undiscovered in the southern sky.


title:
Lepton flavor violation in the Higgs sector and the role of hadronic
  tau-lepton decays

abstract:
  It has been pointed out recently that current low-energy constraints still
allow for sizable flavor-changing decay rates of the 125 GeV boson into
leptons, h -> tau ell (ell= e, mu). In this work we discuss the role of
hadronic tau-lepton decays in probing lepton flavor violating couplings in the
Higgs sector. At low energy, the effective Higgs coupling to gluons induced by
heavy quarks contributes to hadronic tau decays, establishing a direct
connection with the relevant process at the LHC, pp (gg)-> h -> tau ell.
Semileptonic transitions like tau -> ell pi pi are sensitive to flavor-changing
scalar couplings while decays such as tau -> ell eta(') probe pseudoscalar
couplings, thus providing a useful low-energy handle to disentangle possible
Higgs flavor violating signals at the LHC. As part of our analysis, we provide
an appropriate description of all the relevant hadronic matrix elements needed
to describe Higgs-mediated tau -> ell pi pi transitions, improving over
previous treatments in the literature.


title: Galaxy Cluster Baryon Fractions Revisited

abstract:
  We measure the baryons contained in both the stellar and hot gas components
for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper
improves upon our previous work through the addition of XMM data, enabling
measurements of the total mass and masses of each major baryonic component ---
ICM, intracluster stars, and stars in galaxies --- for each system. We recover
a relation for the stellar mass versus halo mass consistent with our previous
result. We confirm that the partitioning of baryons between the stellar and hot
gas components is a strong function of M500; the fractions of total mass in
stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26,
respectively. We also confirm that the combination of the BCG and intracluster
stars is an increasingly important contributor to the stellar baryon budget in
lower halo masses. We find a weak, but statistically significant, dependence of
the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14,
the total baryon fractions within r500 are on average 18% (7%) below the
Universal value from the WMAP7 (Planck) analysis. For Planck, the difference
between the Universal value and cluster baryon fractions is less than the
systematic uncertainties associated with M500. The total baryon fractions
exhibit significant scatter, particularly at M500<2e14 Msun where they range
from 60-90% (65-100%) of the Universal value for WMAP7 (Planck). The ratio of
the stellar-to-gas mass within r500, a measure of star formation efficiency,
strongly decreases with M500. The fact that this relation remains tight at low
mass implies that the larger scatter in the total baryon fractions at these
masses arises from either true scatter in the total baryon content or
observational scatter in M500, rather than late-time physical processes such as
redistribution of gas to beyond r500. (abridged)


title:
Early Disc Accretion as the Origin of Abundance Anomalies in Globular
  Clusters

abstract:
  Globular clusters (GCs), once thought to be well approximated as simple
stellar populations (i.e. all stars having the same age and chemical
abundance), are now known to host a variety of anomalies, such as multiple
discrete (or spreads in) populations in colour-magnitude diagrams and abundance
variations in light elements (e.g., Na, O, Al). Multiple models have been put
forward to explain the observed anomalies, although all have serious
shortcomings (e.g., requiring a non-standard initial mass function of stars and
GCs to have been initially 10-100 times more massive than observed today).
These models also do not agree with observations of massive stellar clusters
forming today, which do not display significant age spreads nor have gas/dust
within the cluster. Here we present a model for the formation of GCs, where low
mass pre-main sequence (PMS) stars accrete enriched material released from
interacting massive binary and rapidly rotating stars onto their circumstellar
discs, and ultimately onto the young stars. As was shown in previous studies,
the accreted material matches the unusual abundances and patterns observed in
GCs. The proposed model does not require multiple generations of
star-formation, conforms to known properties of massive clusters forming today,
and solves the "mass budget problem" without requiring GCs to have been
significantly more massive at birth. Potential caveats to the model as well as
model predictions are discussed.


title:
HST/WFC3 Near-Infrared spectroscopy of quenched galaxies at z~1.5 from
  the WISP Survey: Stellar population properties

abstract:
  We combine Hubble Space Telescope (HST) G102 & G141 NIR grism spectroscopy
with HST/WFC3-UVIS, HST/WFC3-IR and Spitzer/IRAC[3.6\mu m] photometry to
assemble a sample of massive (log(M_star/M_sun) ~ 11) and quenched galaxies at
z~1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy
for quenched sources at these redshifts. In contrast to the local Universe,
z~1.5 quenched galaxies in the high-mass range have a wide range of stellar
population properties. We find their SEDs are well fitted with exponentially
decreasing SFHs, and short star-formation time-scales (\tau<100Myr). Quenched
galaxies also show a wide distribution in ages, between 1-4Gyr. In the
(u-r)_0-versus-mass space quenched galaxies have a large spread in rest-frame
color at a given mass. Most quenched galaxies populate the z~1.5 red-sequence
(RS), but an important fraction of them (32%) have substantially bluer colors.
Although with a large spread, we find that the quenched galaxies ON the RS have
older median ages (3.1Gyr) than the quenched galaxies OFF the RS (1.5Gyr). We
also show that a rejuvenated SED cannot reproduce the observed stacked spectra
of (the bluer) quenched galaxies OFF the RS. We derive the upper limit on the
fraction of massive galaxies ON the RS at z~1.5 to be <43%. We speculate that
the young quenched galaxies OFF the RS are in a transition phase between
vigorous star formation at z>2 and the z~1.5 RS. According to their estimated
ages, the time required for quenched galaxies OFF the RS to join their
counterparts ON the z~1.5 RS is of the order of ~1Gyr.


title: The Last Vestiges of Naturalness

abstract:
  Direct LHC bounds on colored SUSY particles now corner naturalness more than
the measured value of the Higgs mass does. Bounds on the gluino are of
particular importance, since it radiatively "sucks" up the stop and Higgs-up
soft masses. As a result, even models that easily accommodate a 125 GeV Higgs
are almost as tuned as the simplest version of SUSY, the MSSM: at best at the
percent level. In this paper, we further examine how current LHC results
constrain naturalness in three classes of models that may relax LHC bounds on
sparticles: split families, baryonic RPV, and Dirac gauginos. In models of
split families and bRPV, the bounds on the gluino are only slightly reduced,
resulting in a few percent tuning. In particular, having a natural spectrum in
bRPV models typically implies that tops, Ws, and Zs are easily produced in the
cascade decays of squarks and gluinos. The resulting leptons and missing energy
push the gluino mass limit above 1 TeV. Even when the gluino has a Dirac mass
and does not contribute to the stop mass at one loop, tuning reappears in
calculable models because there is no symmetry imposing the supersoft limit. We
conclude that, even if sparticles are found at LHC-14, naturalness will not
emerge triumphant.


title:
Star-formation in active galaxies to z~2: a perspective from Herschel
  studies

abstract:
  In the era of deep, large-area far-infrared (FIR) surveys from the Herschel
Space Telescope, the bulk of the star-formation in distant galaxies, once
hidden by dust, is now being revealed. The FIR provides probably the cleanest
view of SF in the host galaxies of Active Galactic Nuclei (AGNs) over cosmic
time. We report results from studies of the relationships between SF, AGN
activity and AGN obscuration out to z=2.5, which employ some of the deepest
Herschel and X-ray datasets currently available, while spanning orders of
magnitude in the dynamic range of AGN properties. We highlight the role of
gaseous supply in modulating both SF and AGN activity without necessarily
implying a direct causal connection between these phenomenon. The role of
starburst- or major merger-fueled AGN activity at low and high redshifts is
discussed in the context of our results.


title:
Chemical Evolution in High-Mass Star-Forming Regions: Results from the
  MALT90 Survey

abstract:
  The chemical changes of high-mass star-forming regions provide a potential
method for classifying their evolutionary stages and, ultimately, ages. In this
study, we search for correlations between molecular abundances and the
evolutionary stages of dense molecular clumps associated with high-mass star
formation. We use the molecular line maps from Year 1 of the Millimetre
Astronomy Legacy Team 90 GHz (MALT90) Survey. The survey mapped several hundred
individual star-forming clumps chosen from the ATLASGAL survey to span the
complete range of evolution, from prestellar to protostellar to H II regions.
The evolutionary stage of each clump is classified using the Spitzer
GLIMPSE/MIPSGAL mid-IR surveys. Where possible, we determine the dust
temperatures and H2 column densities for each clump from Herschel Hi-GAL
continuum data. From MALT90 data, we measure the integrated intensities of the
N2H+, HCO+, HCN and HNC (1-0) lines, and derive the column densities and
abundances of N2H+ and HCO+. The Herschel dust temperatures increase as a
function of the IR-based Spitzer evolutionary classification scheme, with the
youngest clumps being the coldest, which gives confidence that this
classification method provides a reliable way to assign evolutionary stages to
clumps. Both N2H+ and HCO+ abundances increase as a function of evolutionary
stage, whereas the N2H+ (1-0) to HCO+ (1-0) integrated intensity ratios show no
discernable trend. The HCN (1-0) to HNC(1-0) integrated intensity ratios show
marginal evidence of an increase as the clumps evolve.


title: Floquet Fractional Chern Insulator in Doped Graphene

abstract:
  Fractional Chern insulators are theoretically predicted states of electronic
matter with emergent topological order. They exhibit the same universal
properties as the fractional quantum Hall effect, but dispose of the need to
apply a strong magnetic field. However, despite intense theoretical work, an
experimental realization for these exotic states of matter is still lacking.
Here we show that doped graphene turns into a fractional Chern insulator, when
irradiated with high-intensity circularly polarized light. We derive the
effective steady state band structure of light-driven graphene using Floquet
theory and subsequently study the interacting system with exact numerical
diagonalization. The fractional Chern insulator state equivalent to the 1/3
Laughlin state appears at 7/12 total filling of the honeycomb lattice (1/6
filling of the upper band). The state also features spontaneous ferromagnetism
and is thus an example of the spontaneous breaking of a continuous symmetry
along with a topological phase transition.


title:
Rapid microwave phase detection based on a solid state spiontronic
  device

abstract:
  A technique for rapidly detecting microwave phase has been developed which
uses a spintronic device that can directly rectify microwave fields into a dc
voltage signal. Use of a voltage-controlled phase shifter enables the
development of a spintronic device that can simultaneously 'read' the magnitude
and phase of incident continuous-wave (CW) microwaves when combined with a
lock-in amplifier. As an example of many possible practical applications of
this device, the resonance phase in a complementary electric
inductive-capacitive (CELC) resonator has been characterized using a spintronic
sensor based on a magnetic tunnel junction (MTJ). This sensor device is not
limited for use only with spintronic devices such as MTJs, but can also be used
with semiconductor devices such as microwave detectors, and hence offers a
useful alternative to existing microwave imaging and characterization
technologies.


title:
A Wolf in Sheepskin: Extraordinary Supernova 2012au Veiled Behind
  Ordinary Radio Emission

abstract:
  We present extensive radio and X-ray observations of SN\, 2012au, the
energetic radio luminous supernova of type Ib that may be a link between
subsets of hydrogen-poor superluminous and normal core-collapse supernovae. The
observations closely follow models of synchrotron emission from shock heated
circum-burst medium that has a wind density profile ($\rho \propto r^{-2}$). We
infer a sub-relativistic velocity for the shock wave $v \approx 0.2\,c$ and a
radius of $r \approx 1.4 \times 10^{16} \rm cm$ at 25 days after the estimated
date of explosion. For a constant wind velocity of 1000 km/s we determine the
constant mass loss rate of the progenitor to be $\dot{M} = 3.6 \times 10^{-6}
\rm M_{\odot} yr^{-1}$, consistent with the estimates from X-ray observations.
We estimate the total internal energy of the radio emitting material to be $E
\approx 10^{47} \rm erg$, which is intermediate to SN\,1998bw and SN\,2002ap.
Evolution of the radio light curves of SN\,2012au is consistent with
interaction with a smoothly distributed circum-burst medium and absence of
stellar shells ejected from previous outbursts out to $r \approx 10^{17} \rm
cm$ from the supernova site. Based on this we conclude that the evolution of
the SN\,2012au progenitor star was relatively quiet during the final years
preceding explosion. We find that the bright radio emission from SN2012au was
not dissimilar from other core collapse supernovae despite it's extraordinary
optical properties. We speculate that it was the nature of the explosion that
led to the unusual demise of the SN2012au progenitor star.


title:
Exact solution for high harmonic generation and the response to an ac
  driving field for a charge density wave insulator

abstract:
  We develop and exactly solve a model for electrons driven by pulsed or
continuous ac fields. The theory includes both the photoexcitation process as
well as the subsequent acceleration of the electrons. In the case of an ac
response, we examine both the nonequilibrium density of states and the current.
In the case of pulsed light for high harmonic generation, we find the radiated
light assumes a nearly universal behavior, with only limited dependence on the
parameters of the system, except for the amplitude of the driving field, which
determines the range of high harmonics generated and a tendency toward a
narrowing of the peaks in a charge density wave versus a metal. This type of
high harmonic generation can potentially be used for the creation of
solid-state-based ultrafast light sources.


title:
An Integrated Programming and Development Environment for Adiabatic
  Quantum Optimization

abstract:
  Adiabatic quantum computing is a promising route to the computational power
afforded by quantum information processing. The recent availability of
adiabatic hardware has raised challenging questions about how to evaluate
adiabatic quantum optimization programs. Processor behavior depends on multiple
steps to synthesize an adiabatic quantum program, which are each highly
tunable. We present an integrated programming and development environment for
adiabatic quantum optimization called JADE that provides control over all the
steps taken during program synthesis. JADE captures the workflow needed to
rigorously specify the adiabatic quantum optimization algorithm while allowing
a variety of problem types, programming techniques, and processor
configurations. We have also integrated JADE with a quantum simulation engine
that enables program profiling using numerical calculation. The computational
engine supports plug-ins for simulation methodologies tailored to various
metrics and computing resources. We present the design, integration, and
deployment of JADE and discuss its potential use for benchmarking adiabatic
quantum optimization programs by the quantum computer science community.


title:
Separation of antiferromagnetism and high-temperature superconductivity
  in Ca$_{1-x}$La$_x$Fe$_2$As$_2$ under pressure

abstract:
  We report the effect of applied pressures on magnetic and superconducting
order in single crystals of the aliovalent La-doped iron pnictide material
Ca$_{1-x}$La$_{x}$Fe$_{2}$As$_{2}$. Using electrical transport, elastic neutron
scattering and resonant tunnel diode oscillator measurements on samples under
both quasi-hydrostatic and hydrostatic pressure conditions, we report a series
of phase diagrams spanning the range of substitution concentrations for both
antiferromagnetic and superconducting ground states that include
pressure-tuning through the antiferromagnetic (AFM) quantum critical point. Our
results indicate that the observed superconducting phase with maximum
transition temperature of $T_{c}$=47 K is intrinsic to these materials,
appearing only upon suppression of magnetic order by pressure tuning through
the AFM critical point. In contrast to all other intermetallic iron-pnictide
superconductors with the ThCr$_2$Si$_2$ structure, this superconducting phase
appears to exist only exclusively from the antiferromagnetic phase in a manner
similar to the oxygen- and fluorine-based iron-pnictide superconductors with
the highest transition temperatures reported to date. The unusual dichotomy
between lower-$T_{c}$ systems with coexistent superconductivity and magnetism
and the tendency for the highest-$T_{c}$ systems to show non-coexistence
provides an important insight into the distinct transition temperature limits
in different members of the iron-based superconductor family.


title:
Partial difference equations over compact Abelian groups, II:
  step-polynomial solutions

abstract:
  This paper continues an earlier work on the structure of solutions to two
classes of functional equation. Let $Z$ be a compact Abelian group and $U_1$,
\ldots, $U_k \leq Z$ be closed subgroups. Given $f:Z\to\mathbb{T}$ and $w \in
Z$, one defines the differenced function \[d_wf(z) := f(z+w) - f(z).\] In this
notation, we shall study solutions to the system of difference equations
\[d_{u_1}\cdots d_{u_k}f \equiv 0 \quad \forall (u_1,\ldots,u_k) \in
\prod_{i\leq k}U_i,\] and to the zero-sum problem \[f_1 + \cdots + f_k = 0\]
for functions $f_i:Z\to \mathbb{T}$ that are $U_i$-invariant for each $i$.
  Part I of this work showed that the $Z$-modules of solutions to these
problems can be described using a general theory of `almost modest
$\P$-modules'. Much of the global structure of these solution $Z$-modules could
then be extracted from results about the closure of this general class under
certain natural operations, such as forming cohomology groups. The main result
of the present paper is that solutions to either problem can always be
decomposed into summands which either solve a simpler system of equations, or
have some special `step polynomial' structure. This will be proved by
augmenting the definition of `almost modest $\mathcal{P}$-modules' further, to
isolate a subclass in which elements can be represented by the desired `step
polynomials'. We will then find that this subclass is closed under the same
operations.


title: Identities on Hyperbolic Manifolds

abstract:
  In this survey, we discuss four classes of identities due principally to
Basmajian, McShane, Bridgeman-Kahn and Luo-Tan on hyperbolic manifolds and
provide a unified approach for proving them. We also elucidate on the
connections between the various identities.


title:
Darth Fader: Using wavelets to obtain accurate redshifts of spectra at
  very low signal-to-noise

abstract:
  We present the DARTH FADER algorithm, a new wavelet-based method for
estimating redshifts of galaxy spectra in spectral surveys that is particularly
adept in the very low SNR regime. We use a standard cross-correlation method to
estimate the redshifts of galaxies, using a template set built using a PCA
analysis on a set of simulated, noise-free spectra. Darth Fader employs wavelet
filtering to both estimate the continuum & to extract prominent line features
in each galaxy spectrum. A simple selection criterion based on the number of
features present in the spectrum is then used to clean the catalogue: galaxies
with fewer than six total features are removed as we are unlikely to obtain a
reliable redshift estimate. Applying our wavelet-based cleaning algorithm to a
simulated testing set, we successfully build a clean catalogue including
extremely low signal-to-noise data (SNR=2.0), for which we are able to obtain a
5.1% catastrophic failure rate in the redshift estimates (compared with 34.5%
prior to cleaning). We also show that for a catalogue with uniformly mixed SNRs
between 1.0 & 20.0, with realistic pixel-dependent noise, it is possible to
obtain redshifts with a catastrophic failure rate of 3.3% after cleaning (as
compared to 22.7% before cleaning). Whilst we do not test this algorithm
exhaustively on real data, we present a proof of concept of the applicability
of this method to real data, showing that the wavelet filtering techniques
perform well when applied to some typical spectra from the SDSS archive. The
Darth Fader algorithm provides a robust method for extracting spectral features
from very noisy spectra. The resulting clean catalogue gives an extremely low
rate of catastrophic failures, even when the spectra have a very low SNR. For
very large sky surveys, this technique may offer a significant boost in the
number of faint galaxies with accurately determined redshifts.


title:
The Freedman group: a physical interpretation for the SU(3)-subgroup
  D(18,1,1;2,1,1) of order 648

abstract:
  We study a subgroup $Fr(162\times 4)$ of SU(3) of order 648 which is an
extension of $D(9,1,1;2,1,1)$ and whose generators arise from anyonic systems.
We show that this group is isomorphic to a semi-direct product
$(\mathbb{Z}/18\mathbb{Z}\times\mathbb{Z}/6\mathbb{Z})\rtimes S_3$ with respect
to conjugation and we give a presentation of the group. We show that the group
$D(18,1,1;2,1,1)$ from the series $(D)$ in the existing classification for
finite SU(3)-subgroups is also isomorphic to a semi-direct product
$(\mathbb{Z}/18\mathbb{Z}\times\mathbb{Z}/6\mathbb{Z})\rtimes S_3$, also with
respect to conjugation. We show that the two groups $Fr(162\times 4)$ and
$D(18,1,1;2,1,1)$ are isomorphic and we provide an isomorphism between both
groups. We prove that $Fr(162\times 4)$ is not isomorphic to the exceptional
SU(3) subgroup $\Sigma(216\times 3)$ of the same order 648. We further prove
that the only SU(3) finite subgroups from the 1916 classification by Blichfeldt
or its extended version which $Fr(162\times 4)$ may be isomorphic to belong to
the $(D)$-series. Finally, we show that $Fr(162\times 4)$ and $D(18,1,1;2,1,1)$
are both conjugate under an orthogonal matrix which we provide.


title:
Sharply tunable group velocity in alkali vapors using a single low-power
  control field

abstract:
  We show how a single linearly polarized control field can produce a sharply
tunable group velocity of a weak probe field at resonance in a four-level
atomic configuration of alkali vapors. The dispersion can be switched from
normal to anomalous along with vanishing absorption, just by changing intensity
of the resonant control field. In addition, by allowing different intensities
of the different polarization components of the control field, the anomalous
dispersion can be switched back to the normal. This thereby creates a "valley
of anomaly" in group index variation and offers two sets of control field
intensities, for which the system behaves like a vacuum. The explicit
analytical expressions for the probe coherence are provided along with all
physical explanations. We demonstrate our results in $J = 1/2 \leftrightarrow J
= 1/2$ transition for D_1 lines in alkali atoms, in which one can obtain a
group index as large as $3.2\times10^{8}$ and as negative as $-1.5\times10^{5}$
using a control field with power as low as 0.017 mW/cm$^2$ and 9.56 mW/cm$^2$ .


title: Multihop Routing in Ad Hoc Networks

abstract:
  This paper presents a dual method of closed-form analysis and lightweight
simulation that enables an evaluation of the performance of mobile ad hoc
networks that is more realistic, efficient, and accurate than those found in
existing publications. Some features accommodated by the new analysis are
shadowing, exclusion and guard zones, and distance-dependent fading. Three
routing protocols are examined: least-delay, nearest-neighbor, and
maximum-progress routing. The tradeoffs among the path reliabilities, average
conditional delays, average conditional number of hops, and area spectral
efficiencies are examined.


title:
Physarum wires: Self-growing self-repairing smart wires made from slime
  mould

abstract:
  We report experimental laboratory studies on developing conductive pathways,
or wires, using protoplasmic tubes of plasmodium of acellular slime mould
Physarum polycephalum. Given two pins to be connected by a wire, we place a
piece of slime mould on one pin and an attractant on another pin. Physarum
propagates towards the attract and thus connects the pins with a protoplasmic
tube. A protoplasmic tube is conductive, can survive substantial over-voltage
and can be used to transfer electrical current to lightning and actuating
devices. In experiments we show how to route Physarum wires with
chemoattractants and electrical fields. We demonstrate that Physarum wire can
be grown on almost bare breadboards and on top of electronic circuits. The
Physarum wires can be insulated with a silicon oil without loss of
functionality. We show that a Physarum wire self-heals: end of a cut wire merge
together and restore the conductive pathway in several hours after being cut.
Results presented will be used in future designs of self-growing wetware
circuits and devices, and integration of slime mould electronics into
unconventional bio-hybrid systems.


title: Eigenvalues of Non-Regular Linear-Quasirandom Hypergraphs

abstract:
  Chung, Graham, and Wilson proved that a graph is quasirandom if and only if
there is a large gap between its first and second largest eigenvalue. Recently,
the authors extended this characterization to k-uniform hypergraphs, but only
for the so-called coregular k-uniform hypergraphs. In this paper, we extend
this characterization to all k-uniform hypergraphs, not just the coregular
ones. Specifically, we prove that if a k-uniform hypergraph satisfies the
correct count of a specially defined four-cycle, then there is a gap between
its first and second largest eigenvalue.


title: Stored Luminescence Computed Tomography

abstract:
  The phosphor nanoparticles made of doped semiconductors, pre-excited by
well-collimated X-ray radiation, were recently reported for their light
emission upon NIR light stimulation. The characteristics of X-ray energy
storage and NIR stimulated emission is highly desirable to design targeting
probes and improve molecular and cellular imaging. Here we propose stored
luminescence computed tomography (SLCT), perform realistic numerical
simulation, and demonstrate a much-improved spatial resolution in a preclinical
research context. The future opportunities are also discussed along this
direction.


title: The Optical Design of CHARIS: An Exoplanet IFS for the Subaru Telescope

abstract:
  High-contrast imaging techniques now make possible both imaging and
spectroscopy of planets around nearby stars. We present the optical design for
the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), a
lenslet-based, cryogenic integral field spectrograph (IFS) for imaging
exoplanets on the Subaru telescope. The IFS will provide spectral information
for 138x138 spatial elements over a 2.07 arcsec x 2.07 arcsec field of view
(FOV). CHARIS will operate in the near infrared (lambda = 1.15 - 2.5 microns)
and will feature two spectral resolution modes of R = 18 (low-res mode) and R =
73 (high-res mode). Taking advantage of the Subaru telescope adaptive optics
systems and coronagraphs (AO188 and SCExAO), CHARIS will provide sufficient
contrast to obtain spectra of young self-luminous Jupiter-mass exoplanets.
CHARIS will undergo CDR in October 2013 and is projected to have first light by
the end of 2015. We report here on the current optical design of CHARIS and its
unique innovations.


title:
Discretization of Time-Dependent Quantum Systems: Real-Time Propagation
  of The Evolution Operator

abstract:
  We discuss time dependent quantum systems on bounded domains. Our work may be
viewed as a framework for several models, including linear iterations involved
in time dependent density functional theory (TDDFT), the Hartree-Fock model, or
other quantum models. A key aspect of the analysis of the algorithms is the use
of time-ordered evolution operators, which allow for both a well-posed problem
and its approximation. The approximation theorems obtained for the time-ordered
evolution operators complement those in the current literature. We discuss the
available theory at the outset, and proceed to apply the theory systematically
in later sections via approximations and a global existence theorem for a
nonlinear system, obtained via a fixed point theorem for the evolution
operator. Our work is consistent with first-principle real time propagation of
electronic states, aimed at finding the electronic responses of quantum
molecular systems and nanostructures. We present two full 3D quantum atomistic
simulations using the finite element method for discretizing the real-space,
and the FEAST eigenvalue algorithm for solving the evolution operator at each
time step. These numerical experiments are representative of the theoretical
results.


title:
Monte Carlo Study of a Spin-3/2 Blume-Emery-Griffiths Model on a
  Honeycomb Lattice

abstract:
  We study the phase diagram of the spin-3/2 Blume-Emery-Griffiths model on a
honeycomb lattice by Monte Carlo simulations in order to verify the presence of
some peculiar features predicted by the effective field theory (EFT) with
correlations. The locations of the order-disorder phase boundaries are
estimated from thermal variations of the magnetic susceptibility curves. It is
found that for positive values of the biquadratic interactions the critical
boundary shows a discontinuous character as a function of the single-ion
anisotropy strength, in line with the EFT expectations. However, for negative
values of the biquadratic interactions the step-like variation of the critical
frontier predicted by EFT was not reproduced.


title: Domain dynamics in nonequilibrium random-field Ising models

abstract:
  We employ Monte Carlo simulations in order to study dynamics of the
magnetization and domain growth processes in the random-field Ising models with
uniform and Gaussian random field distributions of varying strengths. Domain
sizes are determined directly using the Hoshen-Kopelman algorithm. For either
case, both the magnetization and the largest domain growth dynamics are found
to follow the power law with generally different exponents, which exponentially
decay with the random field strength. Moreover, for relatively small random
fields the relaxation is confirmed to comply with different regimes at early
and later times. No significant differences were found between the results for
the uniform and Gaussian distributions, in accordance with the universality
assumption.


title:
Low-Temperature Properties of Ising Antiferromagnet on a Stacked
  Triangular Lattice

abstract:
  An Ising antiferromagnet on a stacked triangular lattice in zero field is
studied by Monte Carlo simulations, focusing on the character of the
low-temperature phase and the effect of the relative strength of the exchange
interaction in the stacking direction {\alpha}. Our results support the
presence of the 3D Wannier phase, with the sublattice magnetization structure
(m, -m, 0) and power-law decaying m with the lattice size. The extent of this
low-temperature phase shrinks with decreasing {\alpha}, however, it appears
even at very low values if it is accessed from higher temperatures by
sufficiently slow cooling.


title:
Optimal Power Allocation for Parameter Tracking in a Distributed
  Amplify-and-Forward Sensor Network

abstract:
  We consider the problem of optimal power allocation in a sensor network where
the sensors observe a dynamic parameter in noise and coherently amplify and
forward their observations to a fusion center (FC). The FC uses the
observations in a Kalman filter to track the parameter, and we show how to find
the optimal gain and phase of the sensor transmissions under both global and
individual power constraints in order to minimize the mean squared error (MSE)
of the parameter estimate. For the case of a global power constraint, a
closed-form solution can be obtained. A numerical optimization is required for
individual power constraints, but the problem can be relaxed to a semidefinite
programming problem (SDP), and we show that the optimal result can be
constructed from the SDP solution. We also study the dual problem of minimizing
global and individual power consumption under a constraint on the MSE. As
before, a closed-form solution can be found when minimizing total power, while
the optimal solution is constructed from the output of an SDP when minimizing
the maximum individual sensor power. For purposes of comparison, we derive an
exact expression for the outage probability on the MSE for equal-power
transmission, which can serve as an upper bound for the case of optimal power
control. Finally, we present the results of several simulations to show that
the use of optimal power control provides a significant reduction in either MSE
or transmit power compared with a non-optimized approach (i.e., equal power
transmission).


title:
Thermodynamic properties of a diluted triangular Ising antiferromagnet
  in a field

abstract:
  Within the framework of the effective-field theory with correlations we
investigate effects of an external magnetic field and random site dilution on
basic thermodynamic quantities, such as the magnetization and the magnetic
susceptibility, of the geometrically frustrated triangular lattice Ising
antiferromagnet. Behavior of these quantities is presented in the
temperaturefield parameter space for selected mild degrees of dilution. It is
found that, besides the anomalies associated with phase transitions from the
ferrimagnetic to the paramagnetic state, in some regions of the parameter space
these functions display some more anomalies and peculiarities, as a result of
joint effects of the geometrical frustration, magnetic dilution, thermal
fluctuations and the applied magnetic field.


title: Magnetocaloric properties of a frustrated Blume-Capel antiferromagnet

abstract:
  Low-temperature magnetization processes and magnetocaloric properties of a
geometrically frustrated spin-1 Blume-Capel model on a triangular lattice are
studied by Monte Carlo simulations. The model is found to display qualitatively
different behavior depending on the sign of the single-ion anisotropy D. For
positive values of D we observe two magnetization plateaus, similar to the
spin-1/2 Ising antiferromagnet, and negative isothermal entropy changes for any
field intensity. For a range of small negative values of D there are four
magnetization plateaus and the entropy changes can be either negative or
positive, depending on the field. If D is negative but large in absolute value
then the entropy changes are solely positive.


title: X Ray Detection of GJ 581 and simultaneous UV Observations

abstract:
  Context. GJ 581, an M3 dwarf, hosts a rich system of exo-planets, some of
which are potentially within or at the edge of the Habitable Zone. Nevertheless
the system habitability might be reduced by large and sterilizing high energy
emission flares, if these are frequent. Aims. The GJ 581 radiation environment
was studied with simultaneous X-ray and UV observations, performed with the XRT
and UVOT instruments, respectively, on board of the SWIFT satellite. Methods.
X-ray and UV data were analysed with the distributed standard tools. Results.
GJ 581 was detected for the first time in the 0.2-10 keV range, with an
intensity of (8+-2)x10^{-4} cts/s and a signal-to-noise ratio of 3.6. If
black-body or APEC spectra are assumed then the source X-ray flux is found to
be between 1.8 and 3.3x10^{-14}erg cm^{-2}s^{-1} and log10(L_{X}) between
25.914 and 26.176. Despite hints of X-ray variability, better statistics will
be needed to establish robust evidence for that. The UV measurements, obtained
during 13 pointings, are also reported. A combination of these Swift X-ray and
Hubble Space Telescope UV measurements (with Lyman-alpha) indicate a low X-ray
to UV luminosity ratio of ~4%. Conclusions. Simultaneous X-ray and UV
observations of GJ 581 are reported. These constitute an experimental view of
the system radiation environment, which will be a useful input for the
habitability studies of the GJ 581 planetary system.


title:
Conditional bounds for the least quadratic non-residue and related
  problems

abstract:
  This paper studies explicit and theoretical bounds for several interesting
quantities in number theory, conditionally on the Generalized Riemann
Hypothesis. Specifically, we improve the existing explicit bounds for the least
quadratic non-residue and the least prime in an arithmetic progression. We also
refine the classical conditional bounds of Littlewood for $L$-functions at
$s=1$. In particular, we derive explicit upper and lower bounds for $L(1,\chi)$
and $\zeta(1+it)$, and deduce explicit bounds for the class number of imaginary
quadratic fields. Finally, we improve the best known theoretical bounds for the
least quadratic non-residue, and more generally, the least $k$-th power
non-residue.


title: The $p$-Royden and $p$-harmonic boundaries for metric measure spaces

abstract:
  Let $p$ be a real number greater than one and let $X$ be a locally compact,
noncompact metric measure space that satisfies certain conditions. The
$p$-Royden and $p$-harmonic boundaries of $X$ are constructed by using the
$p$-Royden algebra of functions on $X$ and a Dirichlet type problem is solved
for the $p$-Royden boundary. We also characterize the metric measure spaces
whose $p$-harmonic boundary is empty.


title:
Coverage Probability Analysis for Wireless Networks Using Repulsive
  Point Processes

abstract:
  The recent witnessed evolution of cellular networks from a carefully planned
deployment to more irregular, heterogeneous deployments of Macro, Pico and
Femto-BSs motivates new analysis and design approaches. In this paper, we
analyze the coverage probability in cellular networks assuming repulsive point
processes for the base station deployment. In particular, we characterize,
analytically using stochastic geometry, the downlink probability of coverage
under a Matern hardcore point process to ensure minimum distance between the
randomly located base stations. Assuming a mobile user connects to the nearest
base station and Rayleigh fading, we derive two lower bounds expressions on the
downlink probability of coverage that is within 4% from the simulated scenario.
To validate our model, we compare the probability of coverage of the Matern
hardcore topology against an actual base station deployment obtained from a
public database. The comparison shows that the actual base station deployment
can be fitted by setting the appropriate Matern point process density.


title: Computing for Perturbative QCD - A Snowmass White Paper

abstract:
  We present a study on high-performance computing and large-scale distributed
computing for perturbative QCD calculations.


title: Diffraction of collinear correlated photon pairs by an ultrasonic wave

abstract:
  The phenomenon of collinear correlated photon pairs diffraction by an
ultrasonic wave is investigated for Bragg incidence. A BBO crystal was used for
producing collinear correlated photon pairs via type-I spontaneous parametric
down-conversion (SPDC I-type). It is shown experimentally that the Bragg angle
for photon pairs diffraction is identical to the one corresponding to single
photons diffraction. The numbers of single photons and photon pairs counts in
discrete diffraction orders were measured as functions of the Raman-Nath
parameter. Similarly, the number of coincidence photon counts in separate
diffraction orders was also investigated. What is more, simple analytical
formulas are derived which perfectly describe experimentally obtained data.
OCIS codes: (050.1940) Diffraction; (230.1040) Acousto-optical devices;
(230.4110) Modulators; (270.4180) Multiphoton processes.


title:
A comparative study of the timing and the spectral properties during two
  recent outbursts (2010 & 2011) of H 1743-322

abstract:
  The Galactic black hole candidate (BHC) H~1743-322 recently exhibited two
outbursts in X-rays in August 2010 & April 2011. The nature (outburst profile,
evolution of quasi-periodic oscillation (QPO) frequency and spectral states,
etc.) of these two successive outbursts, which continued for around two months
each, are very similar. We present the results obtained from a comparative
study on the temporal and the spectral properties of the source during these
two outbursts. The evolutions of QPOs observed in both the outbursts were well
fitted with propagating oscillatory shock (POS) model. During both the
outbursts, the observed spectral states (i.e, hard, hard-intermediate,
soft-intermediate and soft) follow the `standard' type of hysteresis-loop,
which could be explained with two component advective flow (TCAF) model.


title: Minimal metrics on 6-dimensional complex nilmanifolds

abstract:
  Let (N,J) be a real 2n-dimensional nilpotent Lie group endowed with an
invariant complex structure. A left-invariant Riemannian metric on N compatible
with J is said to be minimal, if it minimizes the norm of the invariant part of
the Ricci tensor among all compatible metrics on (N,J) with the same scalar
curvature.
  In this paper, we determine all complex structures that admit a minimal
compatible metric on 6-dimensional nilpotent Lie groups.


title:
Properties of the propagating oscillatory shock wave in the accretion
  flows around few transient black hole candidates during their outbursts

abstract:
  In our study of the timing properties of few Galactic black hole candidates
evolutions of the low and intermediate frequency quasi-periodic oscillations
(LIFQPOs) are observed. In 2005, for explaining evolution of QPO frequency
during rising phase of 2005 GRO J1655-40 outburst, Chakrabarti and his students
introduced a new model, namely propagating oscillatory shock (POS) model. Here
we present the results obtained from the same POS model fitted QPO evolutions
during both the rising and declining phases of the outbursts of 2005 GRO
J165540, 2010-11 GX 339-4, and 2010 & 2011 H 1743-322.


title: Heavy Flavor Physics at ATLAS and CMS

abstract:
  Recent results on heavy flavor physics using data from the ATLAS and CMS
detectors are presented. The searches for new physics signatures in CP
violation of B0_s - anti(B0_s) mixing and in B0_d --> K*0 mu+ mu- decays are
discussed. The bottomonium and open-b production results obtained from
proton-proton collisions at LHC are shown. The results are based on data
samples containing mu+ mu- pairs collected with the ATLAS or CMS detectors by
their corresponding muon trigger systems.


title:
Extracting Flow parameters of H 1743-322 during early phase of its 2010
  outburst using Two Component Advective Flow model

abstract:
  We study the spectral properties of Galactic transient black hole candidate H
1743-322 during its early phase of 2010 outburst with Two Component Advective
Flow (TCAF) model, after its inclusion in spectral analysis software package
XSPEC as a local model. For the analysis, spectral data from RXTE/PCA
instrument in 2.5-25 keV energy band are used. From the spectral fit, accretion
flow parameters such as Keplerian (disk) rate, sub-Keplerian (halo) rate,
location of the shock and strength of the shock are directly extracted. QPO
frequencies are predicted from the TCAF model spectral fitted shock parameters,
`closely' matches with the observed frequencies.


title:
Comparing Gravitational Waveform Extrapolation to Cauchy-Characteristic
  Extraction in Binary Black Hole Simulations

abstract:
  We extract gravitational waveforms from numerical simulations of black hole
binaries computed using the Spectral Einstein Code. We compare two extraction
methods: direct construction of the Newman-Penrose (NP) scalar $\Psi_4$ at a
finite distance from the source and Cauchy-characteristic extraction (CCE). The
direct NP approach is simpler than CCE, but NP waveforms can be contaminated by
near-zone effects---unless the waves are extracted at several distances from
the source and extrapolated to infinity. Even then, the resulting waveforms can
in principle be contaminated by gauge effects. In contrast, CCE directly
provides, by construction, gauge-invariant waveforms at future null infinity.
We verify the gauge invariance of CCE by running the same physical simulation
using two different gauge conditions. We find that these two gauge conditions
produce the same CCE waveforms but show differences in extrapolated-$\Psi_4$
waveforms. We examine data from several different binary configurations and
measure the dominant sources of error in the extrapolated-$\Psi_4$ and CCE
waveforms. In some cases, we find that NP waveforms extrapolated to infinity
agree with the corresponding CCE waveforms to within the estimated error bars.
However, we find that in other cases extrapolated and CCE waveforms disagree,
most notably for $m=0$ "memory" modes.


title: Convergence and optimality of the adaptive Morley element method

abstract:
  This paper is devoted to the convergence and optimality analysis of the
adaptive Morley element method for the fourth order elliptic problem. A new
technique is developed to establish a quasi-orthogonality which is crucial for
the convergence analysis of the adaptive nonconforming method. By introducing a
new parameter-dependent error estimator and further establishing a discrete
reliability property, sharp convergence and optimality estimates are then fully
proved for the fourth order elliptic problem.


title:
A Direct Measurement of the Mean Occupation Function of Quasars:
  Breaking Degeneracies between Halo Occupation Distribution Models

abstract:
  Recent work on quasar clustering suggests a degeneracy in the halo occupation
distribution constrained from two-point correlation functions. To break this
degeneracy, we make the first empirical measurement of the mean occupation
function (MOF) of quasars at $z \sim 0.2$ by matching quasar positions with
groups and clusters identified in the MaxBCG sample. We fit two models to the
MOF, a power law and a 4-parameter model. The number distribution of quasars in
host halos is close to Poisson, and the slopes of the MOF obtained from our
best-fit models (for the power law case) favor a MOF that monotonically
increases with halo mass. The best-fit slopes are $0.53 \pm 0.04$ and $1.03\pm
1.12$ for the power law model and the 4-parameter model, respectively. We
measure the radial distribution of quasars within dark matter halos and find it
to be adequately described by a power law with a slope $-2.3 \pm 0.4$. We
measure the conditional luminosity function (CLF) of quasars and show that
there is no evidence that quasar luminosity depends on host halo mass, similar
to the inferences drawn from clustering measurements. We also measure the
conditional black hole mass function (CMF) of our quasars. Although the results
are consistent with no dependence on halo mass, we observe a slight indication
of downsizing of the black hole mass function. The lack of halo mass dependence
in the CLF and CMF shows that quasars residing in galaxy clusters have
characteristic luminosity and black hole mass scales.


title:
Convergence and optimality of the adaptive nonconforming linear element
  method for the Stokes problem

abstract:
  In this paper, we analyze the convergence and optimality of a standard
adaptive nonconforming linear element method for the Stokes problem. After
establishing a special quasi--orthogonality property for both the velocity and
the pressure in this saddle point problem, we introduce a new prolongation
operator to carry through the discrete reliability analysis for the error
estimator. We then use a specially defined interpolation operator to prove
that, up to oscillation, the error can be bounded by the approximation error
within a properly defined nonlinear approximate class. Finally, by introducing
a new parameter-dependent error estimator, we prove the convergence and
optimality estimates.


title:
Stellar haloes in Milky-Way mass galaxies: From the inner to the outer
  haloes

abstract:
  We present a comprehensive study of the chemical properties of the stellar
haloes of Milky-Way mass galaxies, analysing the transition between the inner
to the outer haloes. We find the transition radius between the relative
dominance of the inner-halo and outer-halo stellar populations to be ~15-20 kpc
for most of our haloes, similar to that inferred for the Milky Way from recent
observations. While the number density of stars in the simulated inner-halo
populations decreases rapidly with distance, the outer-halo populations
contribute about 20-40 per cent in the fiducial solar neighborhood, in
particular at the lowest metallicities. We have determined [Fe/H] profiles for
our simulated haloes; they exhibit flat or mild gradients, in the range
[-0.002, -0.01 ] dex/kpc. The metallicity distribution functions exhibit
different features, reflecting the different assembly history of the individual
stellar haloes. We find that stellar haloes formed with larger contributions
from massive subgalactic systems have steeper metallicity gradients. Very
metal-poor stars are mainly contributed to the halo systems by lower-mass
satellites. There is a clear trend among the predicted metallicity distribution
functions that a higher fraction of low-metallicity stars are found with
increasing radius. These properties are consistent with the range of behaviours
observed for stellar haloes of nearby galaxies.


title: Coarse-grained entropy and causal holographic information in AdS/CFT

abstract:
  We propose bulk duals for certain coarse-grained entropies of boundary
regions. The `one-point entropy' is defined in the conformal field theory by
maximizing the entropy in a domain of dependence while fixing the one-point
functions. We conjecture that this is dual to the area of the edge of the
region causally accessible to the domain of dependence (i.e. the `causal
holographic information' of Hubeny and Rangamani). The `future one-point
entropy' is defined by generalizing this conjecture to future domains of
dependence and their corresponding bulk regions. We show that the future
one-point entropy obeys a nontrivial second law. If our conjecture is true,
this answers the question "What is the field theory dual of Hawking's area
theorem?"


title:
Ultrametric Component Analysis with Application to Analysis of Text and
  of Emotion

abstract:
  We review the theory and practice of determining what parts of a data set are
ultrametric. It is assumed that the data set, to begin with, is endowed with a
metric, and we include discussion of how this can be brought about if a
dissimilarity, only, holds. The basis for part of the metric-endowed data set
being ultrametric is to consider triplets of the observables (vectors). We
develop a novel consensus of hierarchical clusterings. We do this in order to
have a framework (including visualization and supporting interpretation) for
the parts of the data that are determined to be ultrametric. Furthermore a
major objective is to determine locally ultrametric relationships as opposed to
non-local ultrametric relationships. As part of this work, we also study a
particular property of our ultrametricity coefficient, namely, it being a
function of the difference of angles of the base angles of the isosceles
triangle. This work is completed by a review of related work, on consensus
hierarchies, and of a major new application, namely quantifying and
interpreting the emotional content of narrative.


title:
Magnetic field tuned superconductor-to-insulator transition at the
  LaAlO$_3$ /SrTiO$_3$ interface

abstract:
  We present a study of the magnetic field tuned superconductor-to-insulator
transition (SIT) in the electron gas that forms at the LaAlO$_3$/SrTiO$_3$
interface. We find that the magnetic field induces a transition into a weakly
insulating state, as is observed for the electrostatically tuned SIT at this
interface. Finite size scaling of the magnetoresistance yields the critical
exponent product $z\nu \simeq$ 7/3, indicating that the transition is governed
by quantum percolation effects. While such critical exponents have been
reported previously for high resistance films, they have not been reported for
a low resistance system like ours, with a maximum sheet resistance of $\approx$
1.5 k$\Omega$, much less than the quantum of resistance $R_Q \equiv h/4e^2 =
6.45$ k$\Omega$.


title:
Weak existence of a solution to a differential equation driven by a very
  rough fBm

abstract:
  We prove that if $f:\mathbb{R}\to\mathbb{R}$ is Lipschitz continuous, then
for every $H\in(0,1/4]$ there exists a probability space on which we can
construct a fractional Brownian motion $X$ with Hurst parameter $H$, together
with a process $Y$ that: (i) is H\"older-continuous with H\"older exponent
$\gamma$ for any $\gamma\in(0,H)$; and (ii) solves the differential equation
$dY_t = f(Y_t) dX_t$. More significantly, we describe the law of the stochastic
process $Y$ in terms of the solution to a non-linear stochastic partial
differential equation.


title:
On the estimation of statistical uncertainties on powder diffraction and
  small angle scattering data from 2-D x-ray detectors

abstract:
  This paper explores optimal methods for obtaining one-dimensional (1D) powder
pattern intensities from two-dimensional (2D) planar detectors with good
estimates of their standard deviations. We describe methods to estimate
uncertainties when the same image is measured in multiple frames as well as
from a single frame. We show the importance of considering the correlation of
diffraction points during the integration and the re-sampling process of data
analysis. We find that correlations between adjacent pixels in the image can
lead to seriously overestimated uncertainties if it is neglected in the
integration process. Off-diagonal entries in the variance-covariance (VC)
matrix are problematic as virtually all data processing and modeling programs
cannot handle the full VC matrix. We show the off-diagonal terms come mainly
from the pixel splitting algorithm used as the default integration algorithm in
many popular 2D integration programs, as well as from re-binning and
re-sampling steps later in the processing. When the full VC matrix can be
propagated during the data reduction, it is possible to get accurate refined
parameters and their uncertainties at the cost of increasing computational
complexity. However, as this is not normally possible, we explore the best
approximate methods for data processing in order to estimate uncertainties on
refined parameters with the greatest accuracy from just the diagonal variance
terms in the VC matrix.


title:
Implicit sampling for path integral control, Monte Carlo localization,
  and SLAM

abstract:
  The applicability and usefulness of implicit sampling in stochastic optimal
control, stochastic localization, and simultaneous localization and mapping
(SLAM), is explored; implicit sampling is a recently-developed
variationally-enhanced sampling method. The theory is illustrated with
examples, and it is found that implicit sampling is significantly more
efficient than current Monte Carlo methods in test problems for all three
applications.


title:
Weyl asymptotics of the transmission eigenvalues for a constant index of
  refraction

abstract:
  We prove Weyl type of asymptotic formulas for the real and the complex
internal transmission eigenvalues when the domain is a ball and the index of
refraction is constant.


title: Nonconventional Spin Glass Transition in a Chemically Ordered Pyrochlore

abstract:
  We report on the study of unusual spin glass properties in the geometrically
frustrated pyrochlore Tb$_{2}$Mo$_{2}$O$_{7}$, $T$$_{g}$$\simeq$24 K. The
analysis of the nonlinear part of dc and complex susceptibilities, near the
glass transition regime, suggests the existence of a statistical distribution
of relaxation times in short-range ordered ferromagnetic clusters. In addition,
the magnetic spins are not sufficiently frozen below the glass transition
temperature; apparently, responsible for the non-equilibrium scaling behavior
of the static critical exponents of nonlinear susceptibilities. Our report is
expected to shed new light in understanding the freezing properties of
frustrated pyrochlores with short range ferromagnetic interactions.


title:
Sensor Search Techniques for Sensing as a Service Architecture for The
  Internet of Things

abstract:
  The Internet of Things (IoT) is part of the Internet of the future and will
comprise billions of intelligent communicating "things" or Internet Connected
Objects (ICO) which will have sensing, actuating, and data processing
capabilities. Each ICO will have one or more embedded sensors that will capture
potentially enormous amounts of data. The sensors and related data streams can
be clustered physically or virtually, which raises the challenge of searching
and selecting the right sensors for a query in an efficient and effective way.
This paper proposes a context-aware sensor search, selection and ranking model,
called CASSARAM, to address the challenge of efficiently selecting a subset of
relevant sensors out of a large set of sensors with similar functionality and
capabilities. CASSARAM takes into account user preferences and considers a
broad range of sensor characteristics, such as reliability, accuracy, location,
battery life, and many more. The paper highlights the importance of sensor
search, selection and ranking for the IoT, identifies important characteristics
of both sensors and data capture processes, and discusses how semantic and
quantitative reasoning can be combined together. This work also addresses
challenges such as efficient distributed sensor search and
relational-expression based filtering. CASSARAM testing and performance
evaluation results are presented and discussed.


title: Physical Bounds on Absorption and Scattering for Cloaked Sensors

abstract:
  We derive and discuss general physical bounds on the electromagnetic
scattering and absorption of passive structures. Our theory, based on passivity
and power conservation, quantifies the minimum and maximum allowed scattering
for an object that absorbs a given level of power. We show that there is a
fundamental trade-off between absorption and overall scattering suppression for
each scattering harmonic, providing a tool to quantify the performance of
furtive sensors, regardless of the applied principle for scattering
suppression. We illustrate these fundamental limitations with examples of light
scattering from absorbing plasmonic nanoparticles and loaded dipole antennas,
envisioning applications to the design of cloaked sensors and absorbers with
maximized absorption efficiency.


title: Geometric Description of L$_1$-Spaces

abstract:
  We describe strongly facially symmetric spaces which are isometrically
isomorphic to L$_1$-space.


title: Efficient finite-time measurements under thermal regimes

abstract:
  Contrary to conventional quantum mechanics, which treats measurement as
instantaneous, here we explore a model for finite-time measurement. The main
two-level system interacts with the measurement apparatus in a Markovian way
described by the Lindblad equation, and with an environment, which does not
include the measuring apparatus. To analyse the environmental effects on the
final density operator, we use the Redfield approach, allowing us to consider a
non-Markovian noise. In the present hybrid theory, to trace out the
environmental degrees of freedom, we use a previously-developed analytic method
based on superoperator algebra and Nakajima-Zwanzig superoperators. Here, we
analyse two types of system-environment interaction, phase and amplitude
damping, which allows us to conclude that, in general, a finite-time quantum
measurement performed during a certain period is more efficient than an
instantaneous measurement performed at the end of it, because the rate of
change of the populations is attenuated by the system-measurement apparatus
interaction.


title: On the pseudo-nullity of the dual fine Selmer groups

abstract:
  In this paper, we will study the pseudo-nullity of the fine Selmer group and
its related question. Namely, we investigate certain situations, where one can
deduce the pseudo-nullity of the dual fine Selmer group of a general Galois
module over a admissible $p$-adic Lie extension $F_{\infty}$ from the knowledge
that pseudo-nullity of the Galois group of the maximal abelian unramified
pro-$p$ extension of $F_{\infty}$ at which every prime of $F_{\infty}$ above
$p$ splits completely. In particular, this gives us a way to construct examples
of the pseudo-nullity of the dual fine Selmer group of a Galois module that is
unramified outside $p$. We will illustrate our results with many examples.


title:
Unified Sum-BER Performance Analysis of AF MIMO Beamforming in Two-Way
  Relay Networks

abstract:
  Unified performance analysis is carried out for amplify-and-forward (AF)
multiple-input-multiple-output (MIMO) beamforming (BF) two-way relay networks
in Rayleigh fading with five different relaying protocols including two novel
protocols for better performance. As a result, a novel closed-form sum-bit
error rate (BER) expression is presented in a unified expression for all
protocols. A new closed-form high signal-to-noise-ratio (SNR) performance is
also obtained in a single expression, and an analytical high-SNR gap expression
between the five protocols is provided. We compare the performance of the five
relaying protocols with respect to sum-BER with appropriately normalized rate
and power, and show that the proposed protocol with four time slots outperforms
other protocols when transmit powers from two sources are sufficiently
different, and the one with three time slots dominates other protocols when
multiple relay antennas are used, at high-SNR.


title:
Experimental Observation of Stabilization and Lasing Death via
  Asymmetric Gain

abstract:
  Using a pair of coupled LRC cavities we experimentally demonstrate that
instabilities and amplification action can be tamed by a spatially inhomogenous
gain. Specifically we observe the counter-intuitive phenomenon of stabilization
of the system even when the overall gain provided is increased. This behavior
is directly related to lasing death via asymmetric pumping, recently proposed
in [M. Liertzer {\it et al}., Phys. Rev. Lett. {\bf 108}, 173901 (2012)]. The
stability analysis of other simple systems reveals the universal nature of the
lasing death phenomenon.


title: A Lower Bound on the Crossing Number of Uniform Hypergraphs

abstract:
  In this paper, we consider the embedding of a complete $d$-uniform geometric
hypergraph with $n$ vertices in general position in $\mathbb{R}^d$, where each
hyperedge is represented as a $(d-1)$-simplex, and a pair of hyperedges is
defined to cross if they are vertex-disjoint and contains a common point in the
relative interior of the simplices corresponding to them. As a corollary of the
Van Kampen-Flores Theorem, it can be seen that such a hypergraph contains
$\Omega(\frac{2^d}{\sqrt{d}})$ $n\choose 2d$ crossing pairs of hyperedges.
Using Gale Transform and Ham Sandwich Theorem, we improve this lower bound to
$\Omega(\frac{2^d \log d}{\sqrt{d}})$ $n\choose 2d$.


title:
High Throughput Screening of Natural Phenolic Compounds Against
  Migration of Metastatic Triple-Negative Breast Cancer (TNBC) Cells

abstract:
  In this report, we hypothesize that natural phenolic compounds may present a
new class of chemotherapeutics against migration of metastatic triple-negative
breast cancers (TNBC). In this project we will screen a small library of
phenolic compounds to test this hypothesis, identify compounds that show
efficacy against TNBC cell migration, and elucidate underlying molecular
mechanisms.


title: Coherent perfect absorption and reflection in slow-light waveguides

abstract:
  We identify a family of unusual slow-light modes occurring in lossy
multi-mode grating waveguides, for which either the forward or backward mode
components, or both, become degenerate. In the fully-degenerate case, by
varying the wave amplitudes in a uniform input waveguide, one can modulate
between coherent perfect absorption (zero reflection) and perfect reflection.
The perfectly-absorbed wave has anomalously short absorption length, scaling as
the inverse 1/3 power of the absorptivity.


title:
Multipath Approach for Reliability in Query Network based Overlaid
  Multicasting

abstract:
  In Application layer multicast (ALM) also called Overlay Multicast,
multicast-related functionalities are moved to end-hosts. The key advantages,
overlays offers, are flexibility, adaptability and ease of deployment [1].
Application layer multicast builds a peer-to-peer (P2P) overlay multicast tree
topology consisting of end-to-end unicast connections between end-hosts. End
users self organize themselves into logical overlay networks for efficient data
delivery. Major concern in designing ALM protocol is how to build and maintain
a topology, to route data efficiently and reliably. We propose here a scheme in
which the topology is built incrementally while maintaining dual feeds of the
media stream to any node from the source with minimum differential delay in
receiving packets from both alternatives. We have made the assumption of
availability of a P2P query search network. This enables building of multicast
tree directly as an overlay. There is no need of maintaining an overlaid mesh
and running multicast routing protocol to maintain a multicast tree in this
mesh. Thus the scheme is much more simplified than in the earlier work on
multicast overlay mesh creation and management and then creation and management
of multicast trees using this mesh.


title: Hyperinner product spaces

abstract:
  In this paper, we introduce the concept of inner product on weak hypervector
spaces and prove some results about them.


title: A 2-categorical extension of the Reshetikhin-Turaev theory

abstract:
  We concretely construct a 2-categorically extended TQFT that extends the
Reshetikhin-Turaev TQFT to cobordisms with corners. The source category will be
a well chosen 2-category of decorated cobordisms with corners and the target
bicategory will be the Kapranov-Voevodsky 2-vector spaces.


title:
Tau neutrino as a probe of nonstandard interactions via charged Higgs
  and $W'$ contribution

abstract:
  We discuss the impact of the presence of a charged Higgs and a $W'$ gauge
boson on the tau-neutrino nucleon scattering $\nu_{\tau}+ N \rightarrow \tau^-
+ X$ and $\bar{\nu}_{\tau}+ N \rightarrow \tau^+ + X$. We show the effect of
the new physics on the three subprocesses quasielastic, $\Delta$-resonance, and
deep inelastic scattering. The measurement of the atmospheric and reactor
mixing angles $\theta_{23}$ and $\theta_{13}$, respectively, relies on the
standard model cross section of the above processes if they have been measured
in the appearance channels $\nu_\mu \rightarrow \nu_\tau$ and $\bar{\nu}_e
\rightarrow \bar{\nu}_\tau$ ($\nu_e \rightarrow \nu_\tau$), respectively.
Consideration of the new physics contributions to those reactions modifies the
measured mixing angles, assuming the standard model cross section. We include
form factor effects in the new physics calculations and find the deviations of
the mixing angles which can be significant and can depend on the energy of the
neutrino.