title:
Insights into the content and spatial distribution of dust from the
  integrated spectral properties of galaxies

abstract:
  [Abridged] We present a new approach to investigate the content and spatial
distribution of dust in structurally unresolved star-forming galaxies from the
observed dependence of integrated spectral properties on galaxy inclination. We
develop an innovative combination of generic models of radiative transfer (RT)
in dusty media with a prescription for the spectral evolution of galaxies, via
the association of different geometric components of galaxies with stars in
different age ranges. We show that a wide range of RT models all predict a
quasi-universal relation between slope of the attenuation curve at any
wavelength and V-band attenuation optical depth in the diffuse interstellar
medium (ISM), at all galaxy inclinations. This relation predicts steeper
(shallower) dust attenuation curves than both the Calzetti and MW curves at
small (large) attenuation optical depths, which implies that geometry and
orientation effects have a stronger influence on the shape of the attenuation
curve than changes in the optical properties of dust grains. We use our
combined RT and spectral evolution model to interpret the observed dependence
of the H\alpha/H\beta\ ratio and ugrizYJH attenuation curve on inclination in a
sample of ~23 000 nearby star-forming galaxies. From a Bayesian MCMC fit, we
measure the central face-on B-band optical depth of this sample to be
tau_B\perp~1.8\pm0.2. We also quantify the enhanced optical depth towards newly
formed stars in their birth clouds, finding this to be significantly larger in
galaxies with bulges than in disc-dominated galaxies, while tau_B\perp is
roughly similar in both cases. Finally, we show that neglecting the effect of
geometry and orientation on attenuation can severely bias the interpretation of
galaxy spectral energy distributions, as the impact on broadband colours can
reach up to 0.3-0.4 mag at optical wavelengths and 0.1 mag at near-infrared
ones.


title: Gamma-ray boxes from axion-mediated dark matter

abstract:
  We compute the gamma-ray output of axion-mediated dark matter and derive the
corresponding constraints set by recent data. In such scenarios the dark matter
candidate is a Dirac fermion that pair-annihilates into axions and/or scalars.
Provided that the axion decays (at least partly) into photons, these models
naturally give rise to a box-shaped gamma-ray spectrum that may present two
distinct phenomenological behaviours: a narrow box, resembling a line at half
the dark matter mass, or a wide box, spanning an extensive energy range up to
the dark matter mass. Remarkably, we find that in both cases a sizable
gamma-ray flux is predicted for a thermal relic without fine-tuning the model
parameters nor invoking boost factors. This large output is in line with recent
Fermi-LAT observations towards the Galactic centre region and is on the verge
of being excluded. We then make use of the Fermi-LAT and H.E.S.S. data to
derive robust, model-independent upper limits on the dark matter annihilation
cross section for the narrow and wide box scenarios. H.E.S.S. constraints, in
particular, turn out to match the ones from Fermi-LAT at hundreds of GeV and
extend to multi-TeV masses. Future Cherenkov telescopes will likely probe
gamma-ray boxes from thermal dark matter relics in the whole multi-TeV range, a
region hardly accessible to direct detection, collider searches and other
indirect detection strategies.


title:
The radial profile of the inner heliospheric magnetic field as deduced
  from Faraday rotation observations

abstract:
  Faraday rotation measures (RMs) of the polarized emission from extragalactic
radio sources occulted by the coronal plasma were used to infer the radial
profile of the inner heliospheric magnetic field near solar minimum activity.
By inverting LASCO/SOHO polarized brightness (pB) data taken during the days of
observations on May 1997, we retrieved the electron density distribution along
the lines of sight to the sources, thus allowing to disentangle the two plasma
properties that contribute to the observed RMs. By comparing the observed RM
values to those theoretically predicted by a power-law model of the radial
component of the coronal magnetic field, using a best-fitting procedure, we
found that the radial component of the inner heliospheric magnetic field can be
nicely approximated by a power-law of the form B_r = 3.76 r^{-2.29} G in a
range of heights from about 5 to 14 solar radii. Finally, our analysis suggests
that the radial computation of the potential field source surface (PFSS) model
from the Wilcox Solar Observatory (WSO), assuming a radial field in the
photosphere and a source surface located at R_{ss} = 2.5 solar radii, is the
preferred choice near solar minimum.


title: Dust-Obscured Galaxies in the Local Universe

abstract:
  We use Wide-field Infrared Survey Explorer (WISE), AKARI, and Galaxy
Evolution Explorer (GALEX) data to select local analogs of high-redshift (z~2)
dust obscured galaxies (DOGs). We identify 47 local DOGs with S_{12\mu
m}/S_{0.22 \mu m}>892 and S_{12\mu m}>20 mJy at 0.05<z<0.08 in the Sloan
Digital Sky Survey data release 7. The infrared luminosities of these DOGs are
in the range 3.4x10^{10} (L_\odot)<L_{IR}<7.0x10^{11} (L_\odot) with a median
L_{IR} of 2.1x10^{11} (L_\odot). We compare the physical properties of local
DOGs with a control sample of galaxies that have lower $S_{12\mu m}/S_{0.22 \mu
m}$ but have similar redshift, IR luminosity, and stellar mass distributions.
Both WISE 12 micron and GALEX near-ultraviolet (NUV) flux densities of DOGs
differ from the control sample of galaxies, but the difference is much larger
in the NUV. Among the 47 DOGs, 36\pm7% have small axis ratios in the optical
(i.e., b/a<0.6), larger than the fraction among the control sample (17\pm3%).
There is no obvious sign of interaction for many local DOGs. No local DOGs have
companions with comparable optical magnitudes closer than ~50 kpc. The large-
and small-scale environments of DOGs are similar to the control sample. Many
physical properties of local DOGs are similar to those of high-z DOGs, even
though the IR luminosities of local objects are an order of magnitude lower
than for the high-z objects: the presence of two classes (active galactic
nuclei- and star formation-dominated) of DOGs, abnormal faintness in the UV
rather than extreme brightness in the mid-infrared, and diverse optical
morphology. These results suggest a common underlying physical origin of local
and high-z DOGs. Both seem to represent the high-end tail of the dust
obscuration distribution resulting from various physical mechanisms rather than
a unique phase of galaxy evolution.


title:
A dynamical model of supernova feedback: gas outflows from the
  interstellar medium

abstract:
  We present a dynamical model of supernova feedback which follows the
evolution of pressurised bubbles driven by supernovae in a multi-phase
interstellar medium (ISM). The bubbles are followed until the point of
break-out into the halo, starting from an initial adiabatic phase to a
radiative phase. We show that a key property which sets the fate of bubbles in
the ISM is the gas surface density, through the work done by the expansion of
bubbles and its role in setting the gas scaleheight. The multi-phase
description of the ISM is essential, and neglecting it leads to order of
magnitude differences in the predicted outflow rates. We compare our predicted
mass loading and outflow velocities to observations of local and high-redshift
galaxies and find good agreement over a wide range of stellar masses and
velocities. With the aim of analysing the dependence of the mass loading of the
outflow, beta (i.e. the ratio between the outflow and star formation rates), on
galaxy properties, we embed our model in the galaxy formation simulation,
GALFORM, set in the LCDM framework. We find that a dependence of beta solely on
the circular velocity, as is widely assumed in the literature, is actually a
poor description of the outflow rate, as large variations with redshift and
galaxy properties are obtained. Moreover, we find that below a circular
velocity of 80km/s the mass loading saturates. A more fundamental relation is
that between beta and the gas scaleheight of the disk, hg, and the gas
fraction, fgas, as beta hg^(1.1) fgas^(0.4), or the gas surface density,
\Sigma_g, and the gas fraction, as beta \Sigma_g^(-0.6) fgas^(0.8). We find
that using the new mass loading model leads to a shallower faint-end slope in
the predicted optical and near-IR galaxy luminosity functions.


title:
Scale-invariant resonance tagging in multijet events and new physics in
  Higgs pair production

abstract:
  We study resonant pair production of heavy particles in fully hadronic final
states by means of jet substructure techniques. We propose a new resonance
tagging strategy that smoothly interpolates between the highly boosted and
fully resolved regimes, leading to uniform signal efficiencies and background
rejection rates across a broad range of masses. Our method makes it possible to
efficiently replace independent experimental searches, based on different final
state topologies, with a single common analysis. As a case study, we apply our
technique to pair production of Higgs bosons decaying into $b\bar{b}$ pairs in
generic New Physics scenarios. We adopt as benchmark models radion and massive
KK graviton production in warped extra dimensions. We find that despite the
overwhelming QCD background, the $4b$ final state has enough sensitivity to
provide a complementary handle in searches for enhanced Higgs pair production
at the LHC.


title: Calculating Track-Based Observables for the LHC

abstract:
  By using observables that only depend on charged particles (tracks), one can
efficiently suppress pile-up contamination at the LHC. Such measurements are
not infrared safe in perturbation theory, so any calculation of track-based
observables must account for hadronization effects. We develop a formalism to
perform these calculations in QCD, by matching partonic cross sections onto new
non-perturbative objects called track functions which absorb infrared
divergences. The track function T_i(x) describes the energy fraction x of a
hard parton i which is converted into charged hadrons. We give a
field-theoretic definition of the track function and derive its renormalization
group evolution, which is in excellent agreement with the Pythia parton shower.
We then perform a next-to-leading order calculation of the total energy
fraction of charged particles in e+ e- -> hadrons. To demonstrate the
implications of our framework for the LHC, we match the Pythia parton shower
onto a set of track functions to describe the track mass distribution in Higgs
plus one jet events. We also show how to reduce smearing due to hadronization
fluctuations by measuring dimensionless track-based ratios.


title: Probing dark matter couplings to top and bottom at the LHC

abstract:
  Monojet searches are a powerful way to place model-independent constraints on
effective operators coupling dark matter to the standard model. For operators
generated by the exchange of a scalar mediator, however, couplings to light
quarks are suppressed and the prospect of probing such interactions through the
inclusive monojet channel at the LHC is limited. We propose dedicated searches,
focusing on bottom and top quark final states, to constrain this class of
operators. We show that a search in mono b-jets can significantly improve
current limits. The mono-b signal arises partly from direct production of
b-quarks in association with dark matter, but the dominant component is from
top quark pair production in the kinematic regime where one top is boosted. A
search for tops plus missing energy can strengthen the bounds even more; in
this case signal and background have very different missing energy
distributions. We find an overall improvement by several orders of magnitude in
the bound on the direct detection cross section for scalar or pseudoscalar
couplings.


title:
Turbulence Induced Collision Velocities and Rates between Different
  Sized Dust Grains

abstract:
  We study the collision rates and velocities for point-particles of different
sizes in turbulent flows. We construct fits for the collision rates at
specified velocities (effectively a collisional velocity probability
distribution) for particle stopping time ratios up to four; already by that
point the collisional partners are very poorly correlated and so the results
should be robust for even larger stopping time ratios. Significantly, we find
that while particles of very different masses have approximately Maxwellian
collisional statistics, as the mass ratio shrinks the distribution changes
dramatically. At small stopping time ratios, the collisional partners are
highly correlated and we find a population of high number density (clustered),
low relative-velocity particle pairs. Unlike in the case of identical stopping
time collisional partners, this low relative-velocity clustered population is
collisional, but the clustering is barely adequate to trigger bulk effects such
as the streaming instability. We conclude our analysis by constructing a master
fit to the collisional statistics as a function only of the stopping time
ratio. Together with our previous work for identical stopping time particle
pairs, this provides a recipe for including collisional velocity probability
distributions in dust coagulation models for protoplanetary disks. We also
include our recipe for determining particle collisional diagnostics from
numerical simulations.


title:
The X-ray spectral properties of very-faint persistent neutron star
  X-ray binaries

abstract:
  AX J1754.2-2754, 1RXS J171824.2-402934 and 1RXH J173523.7-354013 are three
persistent neutron star low-mass X-ray binaries that display a 2--10 keV
accretion luminosity Lx of only (1-10)x1E34 erg s-1 (i.e., only ~0.005-0.05 %
of the Eddington limit). The phenomenology of accreting neutron stars which
accrete at such low accretion rates is not yet well known and the reason why
they have such low accretion rates is also not clear. Therefore, we have
obtained XMM-Newton data of these three sources and here we report our analysis
of the high-quality X-ray spectra we have obtained for them. We find that AX
J1754.2-2754 has Lx~1E35 erg s-1, while the other two have X-ray luminosities
about an order of magnitude lower. However, all sources have a similar,
relatively soft, spectrum with a photon index of 2.3-2.5, when the spectrum is
fitted with an absorbed power-law model. This model fits the data of AX
J1754.2-2754 adequately, but it cannot fit the data obtained for 1RXS
J171824.2-402934 and 1RXH J173523.7-354013. For those sources a clear soft
thermal component is needed to fit their spectra. This soft component
contributes 40% - 50% to the 0.5-10 keV flux of the sources. When including
this additional spectral component, the power-law photon indices are
significantly lower. It can be excluded that a similar component with similar
contributions to the 2-10 keV X-ray flux is present for AX J1754.2-2754,
indicating that the soft spectrum of this source is mostly due to the fact that
the power-law component itself is not hard. We note that we cannot excluded
that weaker soft component is present in the spectrum of this source which only
contributes up to ~25% to the 0.5-10 keV X-ray flux. We discuss our results in
the context of what is known of accreting neutron stars at very low accretion
rate.


title: Toward a Higher-Spin Dual of Interacting Field Theories

abstract:
  We show explicitly how the exact renormalization group equation of
interacting vector models in the large N limit can be mapped into certain
higher-spin equations of motion. The equations of motion are generalized to
incorporate a multiparticle extension of the higher-spin algebra, which
reflects the "multitrace" nature of the interactions in the dual field theory
from the holographic point of view.


title: Powers of squarefree monomial ideals and combinatorics

abstract:
  We survey research relating algebraic properties of powers of squarefree
monomial ideals to combinatorial structures. In particular, we describe how to
detect important properties of (hyper)graphs by solving ideal membership
problems and computing associated primes. This work leads to algebraic
characterizations of perfect graphs independent of the Strong Perfect Graph
Theorem. In addition, we discuss the equivalence between the
Conforti-Cornuejols conjecture from linear programming and the question of when
symbolic and ordinary powers of squarefree monomial ideals coincide.


title: Normalizing Topologically Minimal Surfaces III: Bounded Combinatorics

abstract:
  We show that there are a finite number of possible pictures for a surface in
a tetrahedron with local index $n$. Combined with previous results, this
establishes that any topologically minimal surface can be transformed into one
with a particular normal form with respect to any triangulation.


title:
The WiggleZ Dark Energy Survey: constraining galaxy bias and cosmic
  growth with 3-point correlation functions

abstract:
  Higher-order statistics are a useful and complementary tool for measuring the
clustering of galaxies, containing information on the non-gaussian evolution
and morphology of large-scale structure in the Universe. In this work we
present measurements of the three-point correlation function (3PCF) for 187,000
galaxies in the WiggleZ spectroscopic galaxy survey. We explore the WiggleZ
3PCF scale and shape dependence at three different epochs z=0.35, 0.55 and
0.68, the highest redshifts where these measurements have been made to date.
Using N-body simulations to predict the clustering of dark matter, we constrain
the linear and non-linear bias parameters of WiggleZ galaxies with respect to
dark matter, and marginalise over them to obtain constraints on sigma_8(z), the
variance of perturbations on a scale of 8 Mpc/h and its evolution with
redshift. These measurements of sigma_8(z), which have 10-20% accuracies, are
consistent with the predictions of the LCDM concordance cosmology and test this
model in a new way.


title:
S-Type and P-Type Habitability in Stellar Binary Systems: A
  Comprehensive Approach. I. Method and Applications

abstract:
  A comprehensive approach is provided to the study of both S-type and P-type
habitability in stellar binary systems, which in principle can also be expanded
to systems of higher order. P-type orbits occur when the planet orbits both
binary components, whereas in case of S-type orbits the planet orbits only one
of the binary components with the second component considered a perturbator.
The selected approach encapsulates a variety of different aspects, which
include: (1) The consideration of a joint constraint including orbital
stability and a habitable environment for a putative system planet through the
stellar radiative energy fluxes ("radiative habitable zone"; RHZ) needs to be
met. (2) The treatment of conservative, general and extended zones of
habitability for the various systems as defined for the Solar System and
beyond. (3) The providing of a combined formalism for the assessment of both
S-type and P-type habitability; in particular, mathematical criteria are
presented for which kind of system S-type and P-type habitability is realized.
(4) Applications of the attained theoretical approach to standard (theoretical)
main-sequence stars. In principle, five different cases of habitability are
identified, which are: S-type and P-type habitability provided by the full
extent of the RHZs; habitability, where the RHZs are truncated by the
additional constraint of planetary orbital stability (referred to as ST and
PT-type, respectively); and cases of no habitability at all. Regarding the
treatment of planetary orbital stability, we utilize the formulae of Holman &
Wiegert (1999) [AJ 117, 621], as also used by previous studies. In this work we
focus on binary systems in circular orbits. Future applications will also
consider binary systems in elliptical orbits and provide thorough comparisons
to other methods and results given in the literature.


title: Isotriviality and the space of morphisms on projective varieties

abstract:
  Let $K=k(C)$ be the function field of a smooth projective curve $C$ over an
infinite field $k$, let $X$ be a projective variety over $k$. We prove two
results. First, we show with some conditions that a $K$-morphism $\phi: X_K \to
X_K$ of degree at least two is isotrivial if and only if $\phi$ has potential
good reduction at all places $v$ of $K$. Second, let $(X,\phi), (Y,\psi)$ be
dynamical systems where $X,Y$ are defined over $k$ and $g:X_{K} \to Y_{K}$ a
dominant $K$-morphism, such that $g \circ \phi = \psi \circ g$. We show under
certain conditions that if $\phi$ is defined over $k$, then $\psi$ is defined
over $k$.


title:
Projecting Low Dimensional Chaos from Spatio-temporal Dynamics in a
  Model for Plastic Instability

abstract:
  We investigate the possibility of projecting low dimensional chaos from
spatiotemporal dynamics of a model for a kind of plastic instability observed
under constant strain rate deformation conditions. We first discuss the
relationship between the spatiotemporal patterns of the model reflected in the
nature of dislocation bands and the nature of stress serrations. We show that
at low applied strain rates, there is a one-to-one correspondence with the
randomly nucleated isolated bursts of mobile dislocation density and the stress
drops. We then show that the model equations are spatiotemporally chaotic by
demonstrating the number of positive Lyapunov exponents and Lyapunov dimension
scale with the system size at low and high strain rates. Using a modified
algorithm for calculating correlation dimension density, we show that the
stress-strain signals at low applied strain rates corresponding to spatially
uncorrelated dislocation bands exhibit features of low dimensional chaos. This
is made quantitative by demonstrating that the model equations can be
approximately reduced to space independent model equations for the average
dislocation densities, which is known to be low-dimensionally chaotic. However,
the scaling regime for the correlation dimension shrinks with increasing
applied strain rate due to increasing propensity for propagation of the
dislocation bands.


title: The Embedded Transparent Lens and Fermat's Least-Time Principle

abstract:
  We present a simplified version of the lowest-order embedded point mass
gravitational lens theory and then make the extension of this theory to any
embedded transparent lens. Embedding a lens effectively reduces the
gravitational potential's range, i.e., partially shields the lensing potential
because the lens mass is made a contributor to the mean mass density of the
universe and not simply superimposed upon it. We give the time-delay function
for the embedded point mass lens from which we can derive the simplified lens
equation by applying Fermat's least-time principle. Even though rigorous
derivations are only made for the point mass in a flat background, the
generalization of the lens equation to lowest-order for any distributed lens in
any homogeneous background is obvious. We find from this simplified theory that
embedding can introduce corrections above the few percent level in weak lensing
shears caused by large clusters but only at large impacts. The potential part
of the time delay is also affected in strong lensing at the few percent level.
Additionally we again confirm that the presence of a cosmological constant
alters the gravitational deflection of passing photons.


title: Unsharp Localization and Causality in Relativistic Quantum Theory

abstract:
  The conflict between relativistic causality and localizability is analyzed in
the light of the existence of unsharp localization observables. A theorem due
to S. Schlieder is generalized, showing that the assumption of local
commutativity implies the localization observable in question to be unsharp in
a strong sense. Furthermore, a recent generalization of a theorem of L\"uders
is applied to demonstrate that local commutativity is a necessary consequence
of Einstein causality even in the case of unsharp observables if they admit
local measurements. These findings raise the question whether localization
observables can be measured by means of local operations.


title:
Nonlinear Polarization and Efficiency Droop in Hexagonal InGaN/GaN
  Disk-in-Wire LEDs

abstract:
  Recent studies suggest that piezoelectric polarization can play an important
role in determining the electronic and optical properties of nanoscale nitride
heterostructures. Among a few models available, recent first-principles
calculations performed by Prodhomme et al. provide a simple yet accurate
description of linear and nonlinear piezoelectric coefficients in reduced
dimensionality structures having wurtzite crystal symmetry. In this paper,
first, within a fully atomistic VFF-sp3s* tight-binding framework, we employ
the model proposed by Prodhomme et al. to evaluate the importance of nonlinear
piezoelectricity on the single-particle electronic states and interband optical
transitions in a recently reported hexagon shaped In0.25Ga0.75N/GaN
disk-in-wire LED. The microscopically determined transition parameters are then
incorporated into a TCAD toolkit to investigate how atomicity and the net
polarization field affect the internal quantum efficiency of the LED and lead
to a degraded efficiency droop characteristic


title: Rational functions with maximal radius of absolute monotonicity

abstract:
  We study the radius of absolute monotonicity R of rational functions with
numerator and denominator of degree s that approximate the exponential function
to order p. Such functions arise in the application of implicit s-stage, order
p Runge-Kutta methods for initial value problems and the radius of absolute
monotonicity governs the numerical preservation of properties like positivity
and maximum-norm contractivity. We construct a function with p=2 and R>2s,
disproving a conjecture of van de Griend and Kraaijevanger. We determine the
maximum attainable radius for functions in several one-parameter families of
rational functions. Moreover, we prove earlier conjectured optimal radii in
some families with 2 or 3 parameters via uniqueness arguments for systems of
polynomial inequalities. Our results also prove the optimality of some strong
stability preserving implicit and singly diagonally implicit Runge-Kutta
methods. Whereas previous results in this area were primarily numerical, we
give all constants as exact algebraic numbers.


title: The Thermal Pulses of Very-Low-Mass Stars

abstract:
  Very-low-mass stars can develop secularly unstable hydrogen-burning shells
late in their life. Since the thermal pulses that go along are driven at the
bottoms of very shallow envelopes, the stars' luminosities and effective
temperatures react strongly during a pulse cycle. Towards the end of the
Galaxy's stelliferous era, the hydrogen-shell flashing very-low-mass single
stars should inflict an intricate light-show performed by the large population
of previously inconspicuous dim stars. Unfortunately, this natural spectacle
will discharge too late for mankind to indulge in. Not all is hopeless, though:
In the case of close binary-star evolution, hydrogen-shell flashes of
mass-stripped, very-low mass binary components can develop in a fraction of a
Hubble time. Therefore, the Galaxy should be able put forth a few candidates
that are going to evolve through a H-shell flash in a humanity-compatible time
frame.


title: Dark Two Higgs Doublet Model

abstract:
  We perform a detailed study of a specific Two Higgs Doublet Model (2HDM) with
a U(1) gauge symmetry, instead of a typical Z2 discrete symmetry, containing a
very light gauge boson Z' (GeV scale or below). The Standard Model (SM)
fermions do not carry U(1) charges, but induced couplings to the Z' (called the
dark Z) are generated through mixing with the SM neutral gauge bosons. Such a
light Z' could explain some astrophysical anomalies as well as the muon g-2
deviation, and has been the subject of great experimental interest. We consider
the scenario in which the 125 GeV SM-like Higgs (H) is the heavier scalar
state, and focus on the lighter neutral state (h) as well as charged Higgs. We
analyze the constraints on the model from various experiments and predict novel
channels to search for these Higgs scalars at the LHC. In particular,
experiments looking for lepton-jets are among potentially important searches.


title:
How (In)accurate Are Demand Forecasts in Public Works Projects? The Case
  of Transportation

abstract:
  This article presents results from the first statistically significant study
of traffic forecasts in transportation infrastructure projects. The sample used
is the largest of its kind, covering 210 projects in 14 nations worth US$59
billion. The study shows with very high statistical significance that
forecasters generally do a poor job of estimating the demand for transportation
infrastructure projects. The result is substantial downside financial and
economic risks. Such risks are typically ignored or downplayed by planners and
decision makers, to the detriment of social and economic welfare. For nine out
of ten rail projects passenger forecasts are overestimated; average
overestimation is 106 percent. This results in large benefit shortfalls for
rail projects. For half of all road projects the difference between actual and
forecasted traffic is more than plus/minus 20 percent. Forecasts have not
become more accurate over the 30-year period studied. If techniques and skills
for arriving at accurate demand forecasts have improved over time, as often
claimed by forecasters, this does not show in the data. The causes of
inaccuracy in forecasts are different for rail and road projects, with
political causes playing a larger role for rail than for road. The cure is
transparency, accountability, and new forecasting methods. The challenge is to
change the governance structures for forecasting and project development. The
article shows how planners may help achieve this.


title:
Crossover physics in the non-equilibrium dynamics of quenched quantum
  impurity systems

abstract:
  A general framework is proposed to tackle analytically local quantum quenches
in integrable impurity systems, combining a mapping onto a boundary problem
with the form factor approach to boundary-condition-changing operators
introduced in Phys. Rev. Lett. 80, 4370 (1998). We discuss how to compute
exactly two central quantities of interest: the Loschmidt echo and the
distribution of the work done during the quantum quench. Our results display an
interesting crossover physics characterized by the energy scale T_b of the
impurity corresponding to the Kondo temperature. We discuss in detail the
non-interacting case as a paradigm and benchmark for more complicated
integrable impurity models, and check our results using numerical methods.


title: ARGOS IV: The Kinematics of the Milky Way Bulge

abstract:
  We present the kinematic results from our ARGOS spectroscopic survey of the
Galactic bulge of the Milky Way. Our aim is to understand the formation of the
Galactic bulge. We examine the kinematics of about 17,400 stars in the bulge
located within 3.5 kpc of the Galactic centre, identified from the 28,000 star
ARGOS survey. We aim to determine if the formation of the bulge has been
internally driven from disk instabilities as suggested by its boxy shape, or if
mergers have played a significant role as expected from Lambda CDM simulations.
From our velocity measurements across latitudes b = -5 deg, -7.5 deg and -10
deg we find the bulge to be a cylindrically rotating system that transitions
smoothly out into the disk. Within the bulge, we find a kinematically distinct
metal-poor population ([Fe/H] < -1.0) that is not rotating cylindrically. The
5% of our stars with [Fe/H] < -1.0 are a slowly rotating spheroidal population,
which we believe are stars of the metal weak thick disk and halo which
presently lie in the inner Galaxy. The kinematics of the two bulge components
that we identified in ARGOS paper III (mean [Fe/H] = -0.25 and [Fe/H] = +0.15,
respectively) demonstrate that they are likely to share a common formation
origin and are distinct from the more metal poor populations of the thick disk
and halo which are colocated inside the bulge. We do not exclude an underlying
merger generated bulge component but our results favour bulge formation from
instabilities in the early thin disk.


title:
Phonon influence on the measurement of spin states in double quantum
  dots using the quantum point contact

abstract:
  We study the influence of phonon scattering on the single-triplet measurement
of two-electron spin states in a double quantum dot doped with two electrons.
We point out that at low temperatures phonon-induced relaxation to the ground
state suppresses transitions to doubly occupied singlet states which are the
source of detectable current fluctuations in this measurement scheme. Thus, for
a relatively strong electron-phonon interaction present in the system, the two
configurations display the same noise characteristics. In this way, coupling to
phonons reduces the distinguishability between the singlet and triplet
configurations. Under such conditions, the measurement scheme is no longer
valid even though the temporal characteristics of the measurement process and
measurement- induced localization are essentially unchanged.


title:
Open quantum random walks: bi-stability on pure states and ballistically
  induced diffusion

abstract:
  Open quantum random walks (OQRWs) deal with quantum random motions on the
line for systems with internal and orbital degrees of freedom. The internal
system behaves as a quantum random gyroscope coding for the direction of the
orbital moves. We reveal the existence of a transition, depending on OQRW
moduli, in the internal system behaviors from simple oscillations to random
flips between two unstable pure states. This induces a transition in the
orbital motions from usual diffusion to ballistically induced diffusion with
large mean free path and large effective diffusion constant at large time. We
also show that mixed states of the internal system are converted into random
pure states during the process. We touch upon possible experimental
realizations.


title: The traveling salesman problem for lines, balls and planes

abstract:
  We revisit the traveling salesman problem with neighborhoods (TSPN) and
propose several new approximation algorithms. These constitute either first
approximations (for hyperplanes, lines, and balls in $\mathbb{R}^d$, for $d\geq
3$) or improvements over previous approximations achievable in comparable times
(for unit disks in the plane).
  \smallskip (I) Given a set of $n$ hyperplanes in $\mathbb{R}^d$, a TSP tour
whose length is at most $O(1)$ times the optimal can be computed in $O(n)$
time, when $d$ is constant.
  \smallskip (II) Given a set of $n$ lines in $\mathbb{R}^d$, a TSP tour whose
length is at most $O(\log^3 n)$ times the optimal can be computed in polynomial
time for all $d$.
  \smallskip (III) Given a set of $n$ unit balls in $\mathbb{R}^d$, a TSP tour
whose length is at most $O(1)$ times the optimal can be computed in polynomial
time, when $d$ is constant.


title: Resonance asymptotics for Schrodinger operators on hyperbolic space

abstract:
  We study the asymptotic distribution of resonances for scattering by
compactly supported potentials in hyperbolic space. We first establish an upper
bound for the resonance counting function that depends only on the dimension
and the support of the potential. We then establish the sharpness of this
estimate by proving the a Weyl law for the resonance counting function holds in
the case of radial potentials vanishing to some finite order at the edge of the
support. As an application of the existence of potentials that saturate the
upper bound, we derive additional resonance asymptotics that hold in a suitable
generic sense. These generic results include asymptotics for the resonance
count in sectors.


title: Eigenvalue Coincidences and $K$-orbits, I

abstract:
  We study the variety $\mathfrak{g}(l)$ consisting of matrices $x \in
\mathfrak{gl}(n,\C)$ such that $x$ and its $n-1$ by $n-1$ cutoff $x_{n-1}$
share exactly $l$ eigenvalues, counted with multiplicity. We determine the
irreducible components of $\mathfrak{g}(l)$ by using the orbits of $GL(n-1,\C)$
on the flag variety $\B_n$ of $\mathfrak{gl}(n,\C)$. More precisely, let
$\mathfrak{b} \in \B_n$ be a Borel subalgebra such that the orbit
$GL(n-1,\C)\cdot \mathfrak{b}$ in $\B_n$ has codimension $l$. Then we show that
the set $Y_{\fb}:= \{\Ad(g)(x): x\in \mathfrak{b} \cap \mathfrak{g}(l), g\in
GL(n-1,\C)\}$ is an irreducible component of $\mathfrak{g}(l)$, and every
irreducible component of of $\mathfrak{g}(l)$ is of the form
$Y_{\mathfrak{b}}$, where $\mathfrak{b}$ lies in a $GL(n-1,\C)$-orbit of
codimension $l$. An important ingredient in our proof is the flatness of a
variant of a morphism considered by Kostant and Wallach, and we prove this
flatness assertion using ideas from symplectic geometry.


title: Double zigzag spin chain in strong magnetic field close to saturation

abstract:
  We study the ground state phase diagram of a frustrated spin tube in a strong
external magnetic field. This model can be viewed as two coupled zigzag spin
chains, or as a two-leg spin ladder with frustrating next-nearest-neighbor
couplings along the legs, and its study is motivated by the physics of such
materials as Sulfolane-Cu_{2}Cl_{4} and BiCu_{2}PO_{6}. In magnetic fields
right below the saturation, the system can be effectively represented as a
dilute gas of two species of bosonic quasiparticles that correspond to magnons
with inequivalent incommensurate momenta at two degenerate minima of the magnon
dispersion. Using the method previously proposed and tested for frustrated spin
chains, we calculate effective interactions in this two-component Bose gas. On
this basis, we establish the phase diagram of nearly-saturated frustrated spin
tube, which is shown to include the two-component Luttinger liquid, two types
of vector chiral phases, and phases whose physics is determined by the presence
of bound magnons. We study the phase diagram of the model numerically by means
of the density matrix renormalization group technique, and find a good
agreement with our analytical predictions.


title: On a fractional binomial process

abstract:
  The classical binomial process has been studied by \citet{jakeman} (and the
references therein) and has been used to characterize a series of radiation
states in quantum optics. In particular, he studied a classical birth-death
process where the chance of birth is proportional to the difference between a
larger fixed number and the number of individuals present. It is shown that at
large times, an equilibrium is reached which follows a binomial process. In
this paper, the classical binomial process is generalized using the techniques
of fractional calculus and is called the fractional binomial process. The
fractional binomial process is shown to preserve the binomial limit at large
times while expanding the class of models that include non-binomial
fluctuations (non-Markovian) at regular and small times. As a direct
consequence, the generality of the fractional binomial model makes the proposed
model more desirable than its classical counterpart in describing real physical
processes. More statistical properties are also derived.


title:
The spectra of jet bases in FR I radio galaxies: implications for
  particle acceleration

abstract:
  We present accurate, spatially resolved imaging of radio spectra at the bases
of jets in eleven low-luminosity (Fanaroff-Riley I) radio galaxies, derived
from Very Large Array (VLA) observations. We pay careful attention to
calibration and to the effects of random and systematic errors, and we base the
flux-density scale on recent measurements of VLA primary amplitude calibrators
by Perley & Butler (2013). We show images and profiles of spectral index over
the frequency range 1.4 - 8.5 GHz, together with values integrated over
fiducial regions defined by our relativistic models of the jets. We find that
the spectral index decreases (the spectrum flattens) with distance from the
nucleus in all of the jets. The mean spectral indices are 0.66 +/- 0.01 where
the jets first brighten abruptly and 0.59 +/- 0.01 after they recollimate. The
mean change in spectral index between these locations, which is independent of
calibration and flux-density scale errors and is therefore more accurately and
robustly measured, is -0.067 +/- 0.006. Our jet models associate the decrease
in spectral index with a bulk deceleration of the flow from 0.8c to <0.5c. We
suggest that the decrease is the result of a change in the characteristics of
ongoing particle acceleration. One possible acceleration mechanism is the
first-order Fermi process in mildly relativistic shocks: in the Bohm limit, the
index of the electron energy spectrum, p, is slightly larger than 2 and
decreases with velocity upstream of the shock. This possibility is consistent
with our measurements, but requires shocks throughout the jet volume rather
than at a few discrete locations. A second possibility is that two acceleration
mechanisms operate in these jets: one (with p = 2.32) dominant close to the
galactic nucleus and associated with high flow speeds, another (with p = 2.18)
taking over at larger distances and slower flow speeds.


title: Inverse anisotropic conductivity from internal current densities

abstract:
  This paper concerns the reconstruction of an anisotropic conductivity tensor
$\gamma$ from internal current densities of the form $J = \gamma\nabla u$,
where $u$ solves a second-order elliptic equation $\nabla\cdot(\gamma\nabla u)
= 0$ on a bounded domain $X$ with prescribed boundary conditions. A minimum
number of such functionals equal to $n + 2$, where $n$ is the spatial
dimension, is sufficient to guarantee a local reconstruction. We show that
$\gamma$ can be uniquely reconstructed with a loss of one derivative compared
to errors in the measurement of $J$. In the special case where $\gamma$ is
scalar, it can be reconstructed with no loss of derivatives. We provide a
precise statement of what components may be reconstructed with a loss of zero
or one derivatives.


title:
Characterization of Si Hybrid CMOS Detectors for use in the Soft X-ray
  Band

abstract:
  We report on the characterization of four Teledyne Imaging Systems HAWAII
Hybrid Si CMOS detectors designed for X-ray detection. Three H1RG detectors
were studied along with a specially configured H2RG. Read noise measurements
were performed, with the lowest result being 7.1 e- RMS. Interpixel capacitive
crosstalk (IPC) was measured for the three H1RGs and for the H2RG. The H1RGs
had IPC upper limits of 4.0 - 5.5 % (up & down pixels) and 8.7 - 9.7 % (left &
right pixels), indicating a clear asymmetry. Energy resolution is reported for
two X-ray lines, 1.5 & 5.9 keV, at multiple temperatures between 150 - 210 K.
The best resolution measured at 5.9 keV was 250 eV (4.2 %) at 150 K, with IPC
contributing significantly to this measured energy distribution. The H2RG, with
a unique configuration designed to decrease the capacitive coupling between
ROIC pixels, had an IPC of 1.8 +/- 1.0 % indicating a dramatic improvement in
IPC with no measurable asymmetry. We also measured dark current as a function
of temperature for each detector. For the detector with the lowest dark
current, at 150 K, we measured a dark current of 0.020 +/- 0.001 (e- sec-1
pix-1). There is also a consistent break in the fit to the dark current data
for each detector. Above 180 K, all the data can be fit by the product of a
power law in temperature and an exponential. Below 180 K the dark current
decreases more slowly; a shallow power law or constant must be added to each
fit, indicating a different form of dark current is dominant in this
temperature regime. Dark current figures of merit at 293 K are estimated from
the fit for each detector.


title: Formation of Cystine Slipknots in Dimeric Proteins

abstract:
  We consider mechanical stability of dimeric and monomeric proteins with the
cystine knot motif. A structure based dynamical model is used to demonstrate
that all dimeric and some monomeric proteins of this kind should have
considerable resistance to stretching that is significantly larger than that of
titin. The mechanisms of the large mechanostability are elucidated. In most
cases, it originates from the induced formation of one or two cystine
slipknots. Since there are four termini in a dimer, there are several ways of
selecting two of them to pull by. We show that in the cystine knot systems,
there is strong anisotropy in mechanostability and force patterns related to
the selection. We show that the thermodynamic stability of the dimers is
enhanced compared to the constituting monomers whereas machanostability is
either lower or higher.


title:
Spatial Fay-Herriot Models for Small Area Estimation with Functional
  Covariates

abstract:
  The Fay-Herriot (FH) model is widely used in small area estimation and uses
auxiliary information to reduce estimation variance at undersampled locations.
We extend the type of covariate information used in the FH model to include
functional covariates, such as social-media search loads or remote-sensing
images (e.g., in crop-yield surveys). The inclusion of these functional
covariates is facilitated through a two-stage dimension-reduction approach that
includes a Karhunen-Lo\`{e}ve expansion followed by stochastic search variable
selection. Additionally, the importance of modeling spatial autocorrelation has
recently been recognized in the FH model; our model utilizes the intrinsic
conditional autoregressive class of spatial models in addition to functional
covariates. We demonstrate the effectiveness of our approach through simulation
and analysis of data from the American Community Survey. We use Google Trends
searches over time as functional covariates to analyze relative changes in
rates of percent household Spanish-speaking in the eastern half of the United
States.


title: Ishikawa iteration process on CAT(K) spaces

abstract:
  In this paper, we establish $\Delta$-convergence results for Ishikawa
iterations in complete CAT(K) spaces.


title: Photon bubbles in ultra-cold matter

abstract:
  We show that static and oscillating photon bubbles can be excited by diffused
light in the laser cooled matter confined in a magneto-optical trap (MOT). The
bubble instability is due to the coupling between the radiation field and the
mean field oscillations of the ultra-cold gas, and it can provide a source for
low frequency turbulence. We consider a diffusion dominated regime, which can
be described by a radiation transport equation, coupled with the mean field
equations for the cold atom gas. A perturbative analysis shows the occurrence
of two different regimes with either oscillating or purely growing bubbles.
This work could also be useful to understand similar processes in astrophysics.


title:
Nuclear Quantum Effects and Nonlocal Exchange-Correlation Functionals
  Applied to Liquid Hydrogen at High Pressure

abstract:
  Using first-principles molecular dynamics, we study the influence of nuclear
quantum effects (NQEs) and nonlocal exchange--correlation density functionals
(DFs) near molecular dissociation in liquid hydrogen. NQEs strongly influence
intramolecular properties, such as bond stability, and are thus an essential
part of the dissociation process. Moreover, by including DFs that account for
either the self-interaction error or dispersion interactions, we find a much
better description of molecular dissociation and metallization than previous
studies based on classical protons and/or local or semi-local DFs. We obtain
excellent agreement with experimentally measured optical properties along
pre-compressed Hugoniots, and while we still find a first-order liquid--liquid
transition at low temperatures, transition pressures are increased by more than
100 GPa.


title:
Living on the edge: Phase transitions in convex programs with random
  data

abstract:
  Recent research indicates that many convex optimization problems with random
constraints exhibit a phase transition as the number of constraints increases.
For example, this phenomenon emerges in the $\ell_1$ minimization method for
identifying a sparse vector from random linear measurements. Indeed, the
$\ell_1$ approach succeeds with high probability when the number of
measurements exceeds a threshold that depends on the sparsity level; otherwise,
it fails with high probability.
  This paper provides the first rigorous analysis that explains why phase
transitions are ubiquitous in random convex optimization problems. It also
describes tools for making reliable predictions about the quantitative aspects
of the transition, including the location and the width of the transition
region. These techniques apply to regularized linear inverse problems with
random measurements, to demixing problems under a random incoherence model, and
also to cone programs with random affine constraints.
  The applied results depend on foundational research in conic geometry. This
paper introduces a summary parameter, called the statistical dimension, that
canonically extends the dimension of a linear subspace to the class of convex
cones. The main technical result demonstrates that the sequence of intrinsic
volumes of a convex cone concentrates sharply around the statistical dimension.
This fact leads to accurate bounds on the probability that a randomly rotated
cone shares a ray with a fixed cone.


title:
Towards a Predictive First-Principles Description of Solid Molecular
  Hydrogen with Density-Functional Theory

abstract:
  We examine the influence of the main approximations employed in
density-functional theory descriptions of the solid phase of molecular hydrogen
near dissociation. We consider the importance of nuclear quantum effects on
equilibrium properties and find that they strongly influence intramolecular
properties, such as bond fluctuations and stability. We demonstrate that the
combination of both thermal and quantum effects make a drastic change to the
predicted optical properties of the molecular solid, suggesting a limited value
to dynamical, e.g., finite-temperature, predictions based on classical ions and
static crystals. We also consider the influence of the chosen
exchange--correlation density functional on the predicted properties of
hydrogen, in particular, the pressure dependence of the band gap and the
zero-point energy. Finally, we use our simulations to make an assessment of the
accuracy of typically employed approximations to the calculation of the Gibbs
free energy of the solid, namely the quasi-harmonic approximation for solids.
We find that, while the approximation is capable of producing free energies
with an accuracy of ~10 meV, this is not enough to make reliable predictions of
the phase diagram of hydrogen from first-principles due to the small free
energy differences seen between several potential structures for the solid;
direct free energy calculations for quantum protons are required in order to
make definite predictions.


title: Consensus Algorithms and the Decomposition-Separation Theorem

abstract:
  Convergence properties of time inhomogeneous Markov chain based discrete and
continuous time linear consensus algorithms are analyzed. Provided that a
so-called infinite jet flow property is satisfied by the underlying chains,
necessary conditions for both consensus and multiple consensus are established.
A recenet extension by Sonin of the classical Kolmogorov-Doeblin
decomposition-separation for homogeneous Markov chains to the inhomogeneous
case is then employed to show that the obtained necessary conditions are also
sufficient when the chain is of Class P*, as defined by Touri and Nedic. It is
also shown that Sonin's theorem leads to a rediscovery and generalization of
most of the existing related consensus results in the literature.


title: The Natural Banach Space for Version Independent Risk Measures

abstract:
  Risk measures, or coherent measures of risk are often considered on the space
L^\infty, and important theorems on risk measures build on that space. Other
risk measures, among them the most important risk measure---the Average
Value-at-Risk---are well defined on the larger space L^1 and this seems to be
the natural domain space for this risk measure. Spectral risk measures
constitute a further class of risk measures of central importance, and they are
often considered on some L^p space. But in many situations this is possibly
unnatural, because any L^p with p>p_0, say, is suitable to define the spectral
risk measure as well. In addition to that risk measures have also been
considered on Orlicz and Zygmund spaces. So it remains for discussion and
clarification, what the natural domain to consider a risk measure is? Abstract
This paper introduces a norm, which is built from the risk measure, and a
Banach space, which carries the risk measure in a natural way. It is often
strictly larger than its original domain, and obeys the key property that the
risk measure is finite valued and continuous on that space in an elementary and
natural way.


title: Multi-Determinant Wave-functions in Quantum Monte Carlo

abstract:
  Quantum Monte Carlo (QMC) methods have received considerable attention over
the last decades due to their great promise for providing a direct solution to
the many-body Schrodinger equation in electronic systems. Thanks to their low
scaling with number of particles, QMC methods present a compelling competitive
alternative for the accurate study of large molecular systems and solid state
calculations. In spite of such promise, the method has not permeated the
quantum chemistry community broadly, mainly because of the fixed-node error,
which can be large and whose control is difficult. In this Perspective, we
present a systematic application of large scale multi-determinant expansions in
QMC, and report on its impressive performance with first row dimers and the 55
molecules of the G1 test set. We demonstrate the potential of this strategy for
systematically reducing the fixed-node error in the wave function and for
achieving chemical accuracy in energy predictions. When compared to traditional
quantum chemistry methods like MP2, CCSD(T), and various DFT approximations,
the QMC results show a marked improvement over all of them. In fact, only the
explicitly-correlated CCSD(T) method with a large basis set produces more
accurate results. Further developments in trial wave functions and algorithmic
improvements appear promising for rendering QMC as the benchmark standard in
large electronic systems.


title: GiBUU and Shallow Inelastic Scattering

abstract:
  In this talk we shortly describe the physics contents of the GiBUU transport
code, used to describe lepton scattering off nuclei. Particular attention will
be given to validation of the GiBUU in pion-, electron- and photon-induced
reactions, which serve as a benchmark for neutrino-induced ones. We mainly
concentrate on those properties of benchmark reactions, which are relevant to
the region of Shallow Inelastic Scattering (SIS). Our results in this region
are presented for integrated and differential cross sections. Comparison with
recent MINOS inclusive data, as well as predictions for the differential cross
sections measurable in \Minerva and \Nova experiments are made.


title: The Asymmetric Pupil Fourier Wavefront Sensor

abstract:
  This paper introduces a novel wavefront sensing approach that relies on the
Fourier analysis of a single conventional direct image. In the high Strehl
ratio regime, the relation between the phase measured in the Fourier plane and
the wavefront errors in the pupil can be linearized, as was shown in a previous
work that introduced the notion of generalized closure-phase, or kernel-phase.
The technique, to be usable as presented requires two conditions to be met: (1)
the wavefront errors must be kept small (of the order of one radian or less)
and (2) the pupil must include some asymmetry, that can be introduced with a
mask, for the problem to become solvable. Simulations show that this asymmetric
pupil Fourier wavefront sensing or APF-WFS technique can improve the Strehl
ratio from 50 to over 90 % in just a few iterations, with excellent photon
noise sensitivity properties, suggesting that on-sky close loop APF-WFS is
possible with an extreme adaptive optics system.


title:
Monte Carlo Studies and Optimization for the Calibration System of the
  GERDA Experiment

abstract:
  The GERmanium Detector Array, GERDA, searches for neutrinoless double beta
decay in Ge-76 using bare high-purity germanium detectors submerged in liquid
argon. For the calibration of these detectors gamma emitting sources have to be
lowered from their parking position on top of the cryostat over more than five
meters down to the germanium crystals. With the help of Monte Carlo
simulations, the relevant parameters of the calibration system were determined.
It was found that three Th-228 sources with an activity of 20 kBq each at two
different vertical positions will be necessary to reach sufficient statistics
in all detectors in less than four hours of calibration time. These sources
will contribute to the background of the experiment with a total of (1.07 +/-
0.04(stat) +0.13 -0.19(sys)) 10^{-4} cts/(keV kg yr) when shielded from below
with 6 cm of tantalum in the parking position.


title:
Optimal scaling of the ADMM algorithm for distributed quadratic
  programming

abstract:
  This paper presents optimal scaling of the alternating directions method of
multipliers (ADMM) algorithm for a class of distributed quadratic programming
problems. The scaling corresponds to the ADMM step-size and relaxation
parameter, as well as the edge-weights of the underlying communication graph.
We optimize these parameters to yield the smallest convergence factor of the
algorithm. Explicit expressions are derived for the step-size and relaxation
parameter, as well as for the corresponding convergence factor. Numerical
simulations justify our results and highlight the benefits of optimally scaling
the ADMM algorithm.


title: Simulation and estimation for the fractional Yule process

abstract:
  In this paper, we propose some representations of a generalized linear birth
process called fractional Yule process (fYp). We also derive the probability
distributions of the random birth and sojourn times. The inter-birth time
distribution and the representations then yield algorithms on how to simulate
sample paths of the fYp. We also attempt to estimate the model parameters in
order for the fYp to be usable in practice. The estimation procedure is then
tested using simulated data as well. We also illustrate some major
characteristics of fYp which will be helpful for real applications.


title: Anatomy of the chase

abstract:
  A lot of research activity has recently taken place around the chase
procedure, due to its usefulness in data integration, data exchange, query
optimization, peer data exchange and data correspondence, to mention a few. As
the chase has been investigated and further developed by a number of research
groups and authors, many variants of the chase have emerged and associated
results obtained. Due to the heterogeneous nature of the area it is frequently
difficult to verify the scope of each result. In this paper we take closer look
at recent developments, and provide additional results. Our analysis allows us
create a taxonomy of the chase variations and the properties they satisfy.
  Two of the most central problems regarding the chase is termination, and
discovery of restricted classes of sets of dependencies that guarantee
termination of the chase. The search for the restricted classes has been
motivated by a fairly recent result that shows that it is undecidable to
determine whether the chase with a given dependency set will terminate on a
given instance. There is a small dissonance here, since the quest has been for
classes of sets of dependencies guaranteeing termination of the chase on all
instances, even though the latter problem was not known to be undecidable. We
resolve the dissonance in this paper by showing that determining whether the
chase with a given set of dependencies terminates on all instances is
coRE-complete. Our reduction also gives us the aforementioned
instance-dependent RE-completeness result as a byproduct. For one of the
restricted classes, the stratified sets dependencies, we provide new complexity
results for the problem of testing whether a given set of dependencies belongs
to it. These results rectify some previous claims that have occurred in the
literature.


title: A Review of Dynamic NURBS Approach

abstract:
  Dynamic NURBS, also called D-NURBS, is a known dynamic version of the
nonuniform rational B-spline (NURBS) which integrates free-form shape
representation and a physically-based model in a unified framework. More
recently, computer aided design (CAD) and finite element (FEM) community
realized the need to unify CAD and FEM descriptions which motivates a review of
D-NURBS concepts. Therefore, in this paper we describe D-NURBS theory in the
context of 1D shape deformations. We start with a revision of NURBS for
parametric representation of curve spaces. Then, the Lagrangian mechanics is
introduced in order to complete the theoretical background. Next, the D-NURBS
framework for 1D curve spaces is presented as well as some details about
constraints and numerical implementations. In the experimental results, we
focus on parameters choice and computational cost.


title: Renewal processes based on generalized Mittag--Leffler waiting times

abstract:
  The fractional Poisson process has recently attracted experts from several
fields of study. Its natural generalization of the ordinary Poisson process
made the model more appealing for real-world applications. In this paper, we
generalized the standard and fractional Poisson processes through the waiting
time distribution, and showed their relations to an integral operator with a
generalized Mittag--Leffler function in the kernel. The waiting times of the
proposed renewal processes have the generalized Mittag--Leffler and
stretched-squashed Mittag--Leffler distributions. Note that the generalizations
naturally provide greater flexibility in modeling real-life renewal processes.
Algorithms to simulate sample paths and to estimate the model parameters are
derived. Note also that these procedures are necessary to make these models
more usable in practice. State probabilities and other qualitative or
quantitative features of the models are also discussed.


title:
Brane SUSY Breaking and Inflation: Implications for Scalar Fields and
  CMB Distorsion

abstract:
  I elaborate on a link between the string--scale breaking of supersymmetry
that occurs in a class of superstring models and the onset of inflation. The
link rests on spatially flat cosmologies supported by a scalar field driven by
an exponential potential. If, as in String Theory, this potential is steep
enough, under some assumptions that are spelled out in the text the scalar can
only climb up as it emerges from an initial singularity. In the presence of
another mild exponential, slow--roll inflation is thus injected during the
ensuing descent and definite imprints are left in the CMB power spectrum: the
quadrupole is systematically reduced and, depending on the choice of two
parameters, an oscillatory behavior can also emerge for low multipoles l < 50,
in qualitative agreement with WMAP9 and PLANCK data. The experimentally favored
value of the spectral index, n_s ~ 0.96, points to a potentially important role
for the NS fivebrane, which is unstable in this class of models, in the Early
Universe.


title: Individual Performance and Leader's Laterality in Interactive Contests

abstract:
  Left-handedness is known to provide an intrinsic and tactical advantage at
top level in many sports involving interactive contests. Again, most of the
renowned leaders of the world are known to have been left-handed. Leadership
plays an important role in politics, sports and mentorship. In this paper we
show that Cricket captains who bat left-handed have a strategic advantage over
the right-handed captains in One Day International (ODI) and Test matches. The
present study involving 46 left-handed captains and 148 right-handed captains
in ODI matches, reveal a strong relation between leader's laterality and
team-member performance, demonstrating the critical importance of
left-handedness and successful leadership. The odds for superior batting
performance in an ODI match under left-handed captains are 89% higher than the
odds under right-handed captains. Our study shows that left-handed captains are
more successful in extracting superior performance from the batsmen and bowlers
in ODI and Test matches; perhaps indicating left-handed leaders are better
motivators as leaders when compared to right-handed captains.


title: On the Integral of Fractional Poisson Processes

abstract:
  In this paper we consider the Riemann--Liouville fractional integral
$\mathcal{N}^{\alpha,\nu}(t)= \frac{1}{\Gamma(\alpha)} \int_0^t
(t-s)^{\alpha-1}N^\nu(s) \, \mathrm ds $, where $N^\nu(t)$, $t \ge 0$, is a
fractional Poisson process of order $\nu \in (0,1]$, and $\alpha > 0$. We give
the explicit bivariate distribution $\Pr \{N^\nu(s)=k, N^\nu(t)=r \}$, for $t
\ge s$, $r \ge k$, the mean $\mathbb{E}\, \mathcal{N}^{\alpha,\nu}(t)$ and the
variance $\mathbb{V}\text{ar}\, \mathcal{N}^{\alpha,\nu}(t)$. We study the
process $\mathcal{N}^{\alpha,1}(t)$ for which we are able to produce explicit
results for the conditional and absolute variances and means. Much more
involved results on $\mathcal{N}^{1,1}(t)$ are presented in the last section
where also distributional properties of the integrated Poisson process
(including the representation as random sums) is derived. The integral of
powers of the Poisson process is examined and its connections with generalised
harmonic numbers is discussed.


title: Optimal control of a bioreactor for biofuel production

abstract:
  Dynamic flux balance analysis of a bioreactor is based on the coupling
between a dynamic problem, which models the evolution of biomass, feeding
substrates and metabolites, and a linear program, which encodes the metabolic
activity inside cells. We cast the problem in the language of optimal control
and propose a hybrid formulation to model the full coupling between macroscopic
and microscopic level. On a given location of the hybrid system we analyze
necessary conditions given by the Pontryagin Maximum Principle and discuss the
presence of singular arcs. In particular, for the single-input case we prove
that optimal controls are bang-bang. For the multi-input case, under suitable
assumptions, we prove that generically with respect to initial conditions
optimal controls are bang-bang.


title: Evolution of Galaxies and their Environments at z = 0.1 to 3 in COSMOS

abstract:
  Large-scale structures (LSS) out to z $< 3.0$ are measured in the Cosmic
Evolution Survey (COSMOS) using extremely accurate photometric redshifts
(photoz). The Ks-band selected sample (from Ultra-Vista) is comprised of
155,954 galaxies. Two techniques -- adaptive smoothing and Voronoi tessellation
-- are used to estimate the environmental densities within 127 redshift slices.
Approximately 250 statistically significant overdense structures are identified
out to z $= 3.0$ with shapes varying from elongated filamentary structures to
more circularly symmetric concentrations. We also compare the densities derived
for COSMOS with those based on semi-analytic predictions for a $\Lambda$CDM
simulation and find excellent overall agreement between the mean densities as a
function of redshift and the range of densities. The galaxy properties (stellar
mass, spectral energy distributions (SEDs) and star formation rates (SFRs)) are
strongly correlated with environmental density and redshift, particularly at z
$< 1.0 - 1.2$. Classifying the spectral type of each galaxy using the
rest-frame b-i color (from the photoz SED fitting), we find a strong
correlation of early type galaxies (E-Sa) with high density environments, while
the degree of environmental segregation varies systematically with redshift out
to z $\sim 1.3$. In the highest density regions, 80% of the galaxies are early
types at z=0.2 compared to only 20% at z = 1.5. The SFRs and the star formation
timescales exhibit clear environmental correlations. At z $> 0.8$, the star
formation rate density (SFRD) is uniformly distributed over all environmental
density percentiles, while at lower redshifts the dominant contribution is
shifted to galaxies in lower density environments.


title: Parameter estimation for fractional birth and fractional death processes

abstract:
  The fractional birth and the fractional death processes are more desirable in
practice than their classical counterparts as they naturally provide greater
flexibility in modeling growing and decreasing systems. In this paper, we
propose formal parameter estimation procedures for the fractional Yule, the
fractional linear death, and the fractional sublinear death processes. The
methods use all available data possible, are computationally simple and
asymptotically unbiased. The procedures exploited the natural structure of the
random inter-birth and inter-death times that are known to be independent but
are not identically distributed. We also showed how these methods can be
applied to certain models with more general birth and death rates. The
computational tests showed favorable results for our proposed methods even with
relatively small sample sizes. The proposed methods are also illustrated using
the branching times of the plethodontid salamanders data of \cite{hal79}.


title: Positive Links

abstract:
  Given a link L in the 3-sphere, we ask whether the components of L bound
disjoint, nullhomologous disks properly embedded in a simply-connected
positive-definite smooth 4-manifold; the knot case has been studied extensively
in work of Cochran-Harvey-Horn. Such a 4-manifold is necessarily homeomorphic
to a (punctured) connected sum of CP(2)'s. We characterize all links that are
slice in a (punctured) connected sum of CP(2)'s in terms of ribbon moves and an
operation which we call adding a generalized positive crossing. We find
obstructions in the form of the Levine-Tristram signature function, the signs
of the first author's generalized Sato-Levine invariants, and certain Milnor's
invariants. We show that the signs of coefficients of the Conway polynomial
obstruct a 2-component link from being slice in a single punctured CP(2) and
conjecture these are obstructions in general. These results have applications
to the question of when a 3-manifold bounds a 4-manifold whose intersection
form is that of some connected sum of CP(2)'s. For example, we show that any
homology 3-sphere is cobordant, via a smooth positive definite manifold, to a
connected sum of surgeries on knots in the 3-sphere.


title: Initial data for neutron star binaries with arbitrary spins

abstract:
  The starting point of any general relativistic numerical simulation is a
solution of the Hamiltonian and momentum constraints that (ideally) represents
an astrophysically realistic scenario. We present a new method to produce
initial data sets for binary neutron stars with arbitrary spins and orbital
eccentricities. The method only provides approximate solutions to the
constraints. However, we show that the corresponding constraint violations
subside after a couple of orbits, becoming comparable to those found in
evolutions of standard conformally flat, helically symmetric binary initial
data. We evolve in time three data sets, corresponding to binaries with spins
aligned, zero and anti-aligned with the orbital angular momentum. These
simulations show the orbital "hang-up" effect previously seen in binary black
holes. Additionally, all three show orbital eccentricities up to one order of
magnitude smaller than those found in helically symmetric initial sets
evolutions.


title:
Constitutive modelling of the densification process in silica glass
  under hydrostatic compression

abstract:
  The mechanical response of amorphous silica (or silica glass) under
hydrostatic compression for very high pressures up to 25 GPa is modelled via an
elastic-plastic constitutive equation (continuum mechanics framework).The
material parameters appearing in the theory have been estimated from the ex
situ experimental data from Rouxel et al. [Rouxel T, Ji H, Guin JP, Augereau F,
Ruffle B J Appl Phys 2010;107(9):094903]. The model is shown to capture the
major features of the pressure-volume changes response from the in situ
experimental work of Sato and Funamori [Sato T, Funamori N Phys Rev Lett
2008;101:255502]. In particular, the onset and saturation of densification, the
increase in elasticity parameters (bulk, shear and Youngs moduli) and Poissons
ratio are found to be key parameters of the model.


title:
A Time Projection Chamber for High-Rate Experiments: Towards an Upgrade
  of the ALICE TPC

abstract:
  A Time Projection Chamber (TPC) is a powerful detector for 3-dimensional
tracking and particle identification for ultra-high multiplicity events. It is
the central tracking device of many experiments, e.g. the ALICE experiment at
CERN. The necessity of a switching electrostatic gate, which prevents ions
produced in the amplification region o MWPCs from entering the drift volume,
however, restricts its application to trigger rates of the order of 1 kHz.
  Charge amplification by Gas Electron Multiplier (GEM) foils instead of
proportional wires offers an intrinsic suppression of the ion backflow,
although not to the same level as a gating grid. Detailed Monte Carlo
simulations have shown that the distortions due to residual space charge from
back-drifting ions can be limited to a few cm, and thus can be corrected using
standard calibration techniques. A prototype GEM-TPC has been built with the
largest active volume to date for a detector of this type. It has been
commissioned with cosmics and particle beams at the FOPI experiment at GSI, and
was employed for a physics measurement with pion beams.
  For future operation of the ALICE TPC at the CERN LHC beyond 2019, where
Pb-Pb collision rates of 50 kHz are expected, it is planned to replace the
existing MWPCs by GEM detectors, operated in a continuous, triggerless readout
mode, thus allowing an increase in event rate by a factor of 100. As a first
step of the R&D program, a prototype of an Inner Readout Chamber was equipped
with large-size GEM foils and exposed to beams of protons, pions and electrons
from the CERN PS.
  In this paper, new results are shown concerning ion backflow, spatial and
momentum resolution of the FOPI GEM-TPC, detector calibration, and dE/dx
resolution with both detector prototypes. The perspectives of a GEM-TPC for
ALICE with continuous readout will be discussed.


title: Transient behavior of fractional queues and related processes

abstract:
  We propose a generalization of the classical M/M/1 queue process. The
resulting model is derived by applying fractional derivative operators to a
system of difference-differential equations. This generalization includes both
non-Markovian and Markovian properties, which naturally provide greater
flexibility in modeling real queue systems than its classical counterpart.
Algorithms to simulate M/M/1 queue process and the related linear birth-death
process are provided. Closed-form expressions of the point and interval
estimators of the parameters of these fractional stochastic models are also
presented. These methods are necessary to make these models usable in practice.
The proposed fractional M/M/1 queue model and the statistical methods are
illustrated using S&P data.


title: Measures of Quantum State Purity and Classical Degree of Polarization

abstract:
  There is a well-known mathematical similarity between two-dimensional
classical polarization optics and two-level quantum systems, where the Poincare
and Bloch spheres are identical mathematical structures. This analogy implies
that the classical degree of polarization and quantum purity are in fact the
same quantity. We make extensive use of this analogy to analyze various
measures of polarization for higher dimensions proposed in the literature, in
particular the $N = 3$ case, illustrating interesting relationships that emerge
as well as the advantages of each measure. We also propose a different class of
measures of entanglement based on the purity of subsystems.


title: Cluster categories coming from cyclic posets

abstract:
  Cyclic poset are generalizations of cyclically ordered sets. In this paper we
show that any cyclic poset gives rise to a Frobenius category over any discrete
valuation ring R. The continuous cluster categories of arXiv:1209.1879 are
examples of this construction. If we twist the construction using an admissible
automorphism of the cyclic poset, we generate other examples such as the
m-cluster category of type A-infinity (m>2).


title:
Diagrammatic and Kinetic Equation Analysis of Ultrasoft Fermionic Sector
  in Quark-Gluon Plasma

abstract:
  At so high temperature (T) that the coupling constant (g) is small and the
masses of the particles are negligible, different scheme has to be applied in
each energy scale in the analysis of the quark-gluon plasma (QGP). In the soft
energy region (p gT), the simple perturbative expansion called the hard thermal
loop (HTL) approximation can be applied, and that approximation expects the
existence of the bosonic and fermionic collective excitations called plasmon
and plasmino. On the other hand, in the ultrasoft energy region (p g^2T), the
HTL approximation is inapplicable due to infrared singularity, so the question
whether there are any excitation modes in that energy region has not been
studied well. In this thesis, we analyze the quark spectrum whose energy is
ultrasoft in QGP, using the resummed perturbation theory which enables us to
successfully regularize the infrared singularity. Since the Yukawa model and
QED are simpler than QCD but have some similarity to QCD, we also work in these
models. As a result, we establish the existence of a novel fermionic mode in
the ultrasoft energy region, and obtain the expressions of the pole position
and the strength of that mode. We also show that the Ward-Takahashi identity is
satisfied in the resummed perturbation theory in QED/QCD. Furthermore, we
derive the linearized and generalized Boltzmann equation for the ultrasoft
fermion excitations in the Kadanoff-Baym formalism, and show that the resultant
equation is equivalent to the self-consistent equation in the resummed
perturbation theory. We also derive the equation which determines the n-point
functions with external lines for a pair of fermions and (n-2) bosons with
ultrasoft momenta, by considering the non-linear response regime using the
gauge symmetry. We also derive the Ward-Takahashi identity from the
conservation law of the electromagnetic current in the Kadanoff-Baym formalism.


title: State-dependent Fractional Point Processes

abstract:
  The aim of this paper is the analysis of the fractional Poisson process where
the state probabilities $p_k^{\nu_k}(t)$, $t\ge 0$, are governed by
time-fractional equations of order $0<\nu_k\leq 1$ depending on the number $k$
of events occurred up to time $t$. We are able to obtain explicitely the
Laplace transform of $p_k^{\nu_k}(t)$ and various representations of state
probabilities. We show that the Poisson process with intermediate waiting times
depending on $\nu_k$ differs from that constructed from the fractional state
equations (in the case $\nu_k = \nu$, for all $k$, they coincide with the
time-fractional Poisson process). We also introduce a different form of
fractional state-dependent Poisson process as a weighted sum of homogeneous
Poisson processes. Finally we consider the fractional birth process governed by
equations with state-dependent fractionality.


title:
Two General Methods for Population Pharmacokinetic Modeling:
  Non-Parametric Adaptive Grid and Non-Parametric Bayesian

abstract:
  Population pharmacokinetic (PK) modeling methods can be statistically
classified as either parametric or nonparametric (NP). Each classification can
be divided into maximum likelihood (ML) or Bayesian (B) approaches. In this
paper we discuss the nonparametric case using both maximum likelihood and
Bayesian approaches. We present two nonparametric methods for estimating the
unknown joint population distribution of model parameter values in a
pharmacokinetic/pharmacodynamic (PK/PD) dataset. The first method is the NP
Adaptive Grid (NPAG). The second is the NP Bayesian (NPB) algorithm with a
stick-breaking process to construct a Dirichlet prior. Our objective is to
compare the performance of these two methods using a simulated PK/PD dataset.
Our results showed excellent performance of NPAG and NPB in a realistically
simulated PK study. This simulation allowed us to have benchmarks in the form
of the true population parameters to compare with the estimates produced by the
two methods, while incorporating challenges like unbalanced sample times and
sample numbers as well as the ability to include the covariate of patient
weight. We conclude that both NPML and NPB can be used in realistic PK/PD
population analysis problems. The advantages of one versus the other are
discussed in the paper. NPAG and NPB are implemented in R and freely available
for download within the Pmetrics package from www.lapk.org.


title: Quantum-Secured Surveillance Based on Mach-Zehnder Interferometry

abstract:
  We present a method for intrusion detection which is based on the
Mach-Zehnder interference effect. This device provides monitored surveillance
by continuously measuring the intensity of light collected by a pair of
photodetectors. We find that our protocol allows for the detection of intrusion
attempts which employ path- redirection and/or intercept-resend techniques.
Expectation values for the registered output flux are provided for normal and
interrupted operation.


title:
XTE J1752-223 in outburst: a persistent radio jet, dramatic flaring,
  multiple ejections and linear polarisation

abstract:
  The black hole candidate, XTE J1752-223, was discovered in 2009 October when
it entered an outburst. We obtained radio data from the Australia Telescope
Compact Array for the duration of the ~9 month event. The lightcurves show that
the radio emission from the compact jet persisted for the duration of an
extended hard state and through the transition to the intermediate state. The
flux then rose rapidly by a factor of 10 and the radio source entered a series
of at least 7 maxima, the first of which was likely to be emission associated
with the compact jet. The subsequent 6 flares were accompanied by variable
behaviour in terms of radio spectrum, degree of linear polarisation, morphology
and associated X-ray behaviour. They were, however, remarkably similar in terms
of the estimated minimum power required to launch such an ejection event. We
compare the timing of radio peaks with the location of the ejecta, imaged by
contemporaneous VLBI experiments. We then discuss the mechanism behind the
events, in terms of whether discrete ejections is the most likely description
of the behaviour. One ejection, at least, appears to be travelling with
apparent superluminal motion. The range of properties, however, suggests that
mutiple mechanisms may be relevant and that at least some of the emission is
coming from shocked interactions amongst the ejecta and between the ejecta and
the interstellar medium. We also compare the radio flux density with the X-ray
source during the hard state and conclude that XTE J1752-223 is a
radio-weak/X-ray-bright outlier on the universal correlation for black hole
transient sources.


title: Vector-like leptons and extra gauge symmetry for the natural Higgs boson

abstract:
  For raising the radiative Higgs mass without a serious fine-tuning in the
Higgs sector, we introduce vector-like lepton doublets and neutral singlets
{L,L^c; N,N^c}, and consider their order one Yukawa coupling to the Higgs, W
\supset y_NLh_uN^c. The 125 GeV Higgs mass can be naturally explained with the
stop mass squared of ~(500 GeV)^2 and even without the "A-term" contributions.
It is possible because of the quartic power of y_N in the radiative Higgs mass
correction, and much less stringent mass bounds on extra leptonic matter. In
order to avoid blowup of y_N at higher energy scales, a non-Abelian gauge
extension of the MSSM is attempted, under which {L,L^c; N,N^c} are charged,
while all the ordinary MSSM superfields remain neutral. We discuss the gauge
coupling unification. This mechanism can be applied also for enhancing h^0
\rightarrow \gamma\gamma with W \supset y_EL^ch_uE, if the charged lepton
singlets {E,E^c} are also introduced.


title: Revisiting the Equivalence Problem for Finite Multitape Automata

abstract:
  The decidability of determining equivalence of deterministic multitape
automata (or transducers) was a longstanding open problem until it was resolved
by Harju and Karhum\"{a}ki in the early 1990s. Their proof of decidability
yields a co_NP upper bound, but apparently not much more is known about the
complexity of the problem. In this paper we give an alternative proof of
decidability, which follows the basic strategy of Harju and Karhumaki but
replaces their use of group theory with results on matrix algebras. From our
proof we obtain a simple randomised algorithm for deciding language equivalence
of deterministic multitape automata and, more generally, multiplicity
equivalence of nondeterministic multitape automata. The algorithm involves only
matrix exponentiation and runs in polynomial time for each fixed number of
tapes. If the two input automata are inequivalent then the algorithm outputs a
word on which they differ.


title: Partitions with equal products and elliptic curves

abstract:
  Let $a,b,c$ be distinct positive integers. Set $M=a+b+c$ and $N=abc$. We give
an explicit description of the Mordell-Weil group of the elliptic curve
$\displaystyle E_{(M,N)}:y^2-Mxy-Ny=x^3$ over $\Q$. In particular we determine
the torsion subgroup of $E_{(M,N)}(\Q)$ and show that its rank is positive.
Furthermore there are infinitely many positive integers $M$ that can be written
in $n$ different ways, $n\in\{2,3\}$, as the sum of three distinct positive
integers with the same product $N$ and $E_{(M,N)}(\Q)$ has rank at least $n$.


title: Formal Groups and Invariant Differentials of Elliptic Curves

abstract:
  In this paper, we find a power series expansion of the invariant differential
$\omega_E$ of an elliptic curve $E$ defined over $\mathbb{Q}$, where $E$ is
described by certain families of Weierstrass equations. In addition, we
introduce several congruence relations satisfied by the trace of the Frobenius
endomorphism of $E$.


title:
NASA ExoPAG Study Analysis Group 5: Flagship Exoplanet Imaging Mission
  Science Goals and Requirements Report

abstract:
  The NASA Exoplanet Program Analysis Group (ExoPAG) has undertaken an effort
to define mission Level 1 requirements for exoplanet direct detection missions
at a range of sizes. This report outlines the science goals and requirements
for the next exoplanet flagship imaging and spectroscopy mission as determined
by the flagship mission Study Analysis Group (SAG) of the NASA Exoplanet
Program Analysis Group (ExoPAG). We expect that these goals and requirements
will be used to evaluate specific architectures for a future flagship exoplanet
imaging and spectroscopy mission, and we expect this effort to serve as a guide
and template for similar goals and requirements for smaller missions, an effort
that we expect will begin soon. These goals and requirements were discussed,
determined, and documented over a 1 year period with contributions from
approximately 60 volunteer exoplanet scientists, technologists, and engineers.
Numerous teleconferences, emails, and several in-person meetings were conducted
to progress on this task, resulting in creating and improving drafts of mission
science goals and requirements. That work has been documented in this report as
a set of science goals, more detailed objectives, and specific requirements
with deliberate flow-down and linkage between each of these sets. The specific
requirements have been developed in two categories: "Musts" are nonnegotiable
hard requirements, while "Discriminator" requirements assign value to
performance in areas beyond the floor values set by the "Musts." We believe
that this framework and content will ensure that this report will be valuable
when applied to future mission evaluation activities. We envision that any
future exoplanet imaging flagship mission must also be capable of conducting a
broad range of other observational astrophysics. We expect that this will be
done by the NASA Cosmic Origins Program Analysis Group (COPAG).


title:
Reward-based learning under hardware constraints - Using a RISC
  processor embedded in a neuromorphic substrate

abstract:
  In this study, we propose and analyze in simulations a new, highly flexible
method of implementing synaptic plasticity in a wafer-scale, accelerated
neuromorphic hardware system. The study focuses on globally modulated STDP, as
a special use-case of this method. Flexibility is achieved by embedding a
general-purpose processor dedicated to plasticity into the wafer. To evaluate
the suitability of the proposed system, we use a reward modulated STDP rule in
a spike train learning task. A single layer of neurons is trained to fire at
specific points in time with only the reward as feedback. This model is
simulated to measure its performance, i.e. the increase in received reward
after learning. Using this performance as baseline, we then simulate the model
with various constraints imposed by the proposed implementation and compare the
performance. The simulated constraints include discretized synaptic weights, a
restricted interface between analog synapses and embedded processor, and
mismatch of analog circuits. We find that probabilistic updates can increase
the performance of low-resolution weights, a simple interface between analog
synapses and processor is sufficient for learning, and performance is
insensitive to mismatch. Further, we consider communication latency between
wafer and the conventional control computer system that is simulating the
environment. This latency increases the delay, with which the reward is sent to
the embedded processor. Because of the time continuous operation of the analog
synapses, delay can cause a deviation of the updates as compared to the not
delayed situation. We find that for highly accelerated systems latency has to
be kept to a minimum. This study demonstrates the suitability of the proposed
implementation to emulate the selected reward modulated STDP learning rule.


title: New Limit on Lorentz Violation Using a Double-Pass Optical Ring Cavity

abstract:
  A search for Lorentz violation in electrodynamics was performed by measuring
the resonant frequency difference between two counterpropagating directions of
an optical ring cavity. Our cavity contains a dielectric element, which makes
our cavity sensitive to the violation. The laser frequency is stabilized to the
counterclockwise resonance of the cavity, and the transmitted light is
reflected back into the cavity for resonant frequency comparison with the
clockwise resonance. This double-pass configuration enables a null experiment
and gives high common mode rejection of environmental disturbances. We found no
evidence for odd-parity anisotropy at the level of $\delta c /c \lesssim
10^{-14}$. Within the framework of the Standard Model Extension, our result put
more than 5 times better limits on three odd-parity parameters
$\tilde{\kappa}^{JK}_{o+}$ and a 12 times better limit on the scalar parameter
$\tilde{\kappa}_{\tr}$ compared with the previous best limits.


title: Imaginary cones and limit roots of infinite Coxeter groups

abstract:
  Let (W,S) be an infinite Coxeter system. To each geometric representation of
W is associated a root system. While a root system lives in the positive side
of the isotropy cone of its associated bilinear form, an imaginary cone lives
in the negative side of the isotropic cone. Precisely on the isotropic cone,
between root systems and imaginary cones, lives the set E of limit points of
the directions of roots (see arXiv:1112.5415). In this article we study the
close relations of the imaginary cone (see arXiv:1210.5206) with the set E,
which leads to new fundamental results about the structure of geometric
representations of infinite Coxeter groups. In particular, we show that the
W-action on E is minimal and faithful, and that E and the imaginary cone can be
approximated arbitrarily well by sets of limit roots and imaginary cones of
universal root subsystems of W, i.e., root systems for Coxeter groups without
braid relations (the free object for Coxeter groups). Finally, we discuss open
questions as well as the possible relevance of our framework in other areas
such as geometric group theory.


title:
An intelligent approach towards automatic shape modeling and object
  extraction from satellite images using cellular automata based algorithm

abstract:
  Automatic feature extraction domain has witnessed the application of many
intelligent methodologies over past decade; however detection accuracy of these
approaches were limited as object geometry and contextual knowledge were not
given enough consideration. In this paper, we propose a frame work for accurate
detection of features along with automatic interpolation, and interpretation by
modeling feature shape as well as contextual knowledge using advanced
techniques such as SVRF, Cellular Neural Network, Core set, and MACA. Developed
methodology has been compared with contemporary methods using different
statistical measures. Investigations over various satellite images revealed
that considerable success was achieved with the CNN approach. CNN has been
effective in modeling different complex features effectively and complexity of
the approach has been considerably reduced using corset optimization. The
system has dynamically used spectral and spatial information for representing
contextual knowledge using CNN-prolog approach. System has been also proved to
be effective in providing intelligent interpolation and interpretation of
random features.


title: On expanding foliations

abstract:
  Certain families of manifolds which support Anosov flows do not support
expanding, quasi-isometric foliations.


title: Bulk and Surface Tunneling Hydrogen Defects in Alumina

abstract:
  We perform ab initio calculations of hydrogen-based tunneling defects in
alumina to identify deleterious two-level systems (TLS) in superconducting
qubits. The defects analyzed include bulk hydrogenated Al vacancies, bulk
hydrogen interstitial defects, and a surface OH rotor. The formation energies
of the defects are first computed for an Al- and O-rich environment to give the
likelihood of defect occurrence during growth. The potential energy surfaces
are then computed and the corresponding dipole moments are evaluated to
determine the coupling of the defects to an electric field. Finally, the
tunneling energy is computed for the hydrogen defect and the analogous
deuterium defect, providing an estimate of the TLS energy and the corresponding
frequency for photon absorption. We predict that hydrogenated cation vacancy
defects will form a significant density of GHz-frequency TLSs in alumina.


title: Foliations on non-metrisable manifolds II: contrasted behaviours

abstract:
  This paper, which is an outgrowth of a previous paper of the authors,
continues the study of dimension 1 foliations on non-metrisable manifolds
emphasising some anomalous behaviours. We exhibit surfaces with various extra
properties like Type I, separability and simple connectedness, and a property
which we call `squat,' which do not admit foliations even on removal of a
compact (or even Lindel\"of) subset. We exhibit a separable surface carrying a
foliation in which all leaves except one are metrisable but at the same time we
prove that every non-metrisable leaf on a Type I manifold has a saturated
neighbourhood consisting only of non-metrisable leaves. Minimal foliations are
also considered. Finally we exhibit simply connected surfaces having infinitely
many topologically distinct foliations.


title:
New Superconductivity in Layered 1T-TaS2-xSex Single Crystals Fabricated
  by Chemical Vapor Transport

abstract:
  Layered transition-metal dichalcogenides 1T-TaS2-xSex (0<=x<=2) single
crystals have been successfully fabricated by using a chemical vapor transport
technique in which Ta locates in octahedral coordination with S and Se atoms.
This is the first superconducting example by the substitution of S site, which
violates an initial rule based on the fact that superconductivity merely
emerges in 1T-TaS2 by applying the high pressure or substitution of Ta site. We
demonstrate the appearance of a series of electronic states in 1T-TaS2-xSex
with Se content. Namely, the Mott phase melts into a nearly commensurate
charge-density-wave (NCCDW) phase, superconductivity in a wide x range develops
within the NCCDW state, and finally commensurate charge-density-wave (CCDW)
phase reproduces for heavy Se content. The present results reveal that
superconductivity is only characterized by robust Ta 5d band, demonstrating the
universal nature in 1T-TaS2 systems that superconductivity and NCCDW phase
coexist in the real space.


title: Symmetry protected entanglement renormalization

abstract:
  Entanglement renormalization is a real-space renormalization group (RG)
transformation for quantum many-body systems. It generates the multi-scale
entanglement renormalization ansatz (MERA), a tensor network capable of
efficiently describing a large class of many-body ground states, including
those of systems at a quantum critical point or with topological order. The
MERA has also been proposed to be a discrete realization of the holographic
principle of string theory. In this paper we propose the use of symmetric
tensors as a mechanism to build a symmetry protected RG flow, and discuss two
important applications of this construction. First, we argue that symmetry
protected entanglement renormalization produces the proper structure of RG
fixed-points, namely a fixed-point for each symmetry protected phase. Second,
in the context of holography, we show that by using symmetric tensors, a global
symmetry at the boundary becomes a local symmetry in the bulk, thus explicitly
realizing in the MERA a characteristic feature of the AdS/CFT correspondence.