title: Generating buoyant magnetic flux ropes in solar-like convective dynamos

abstract:
  Our Sun exhibits strong convective dynamo action which results in magnetic
flux bundles emerging through the stellar surface as magnetic spots.
Global-scale dynamo action is believed to generate large-scale magnetic
structures in the deep solar interior through the interplay of convection,
rotation, and shear. Portions of these large-scale magnetic structures are then
believed to rise through the convective layer, forming magnetic loops which
then pierce the photosphere as sunspot pairs. Previous global simulations of 3D
MHD convection in rotating spherical shells have demonstrated mechanisms
whereby large-scale magnetic wreaths can be generated in the bulk of the
convection zone. Our recent simulations have achieved sufficiently high levels
of turbulence to permit portions of these wreaths to become magnetically
buoyant and rise through the simulated convective layer through a combination
of magnetic buoyancy and advection by convective giant cells. These buoyant
magnetic loops are created in the bulk of the convective layer as strong
Lorentz force feedback in the cores of the magnetic wreaths dampen small-scale
convective motions, permitting the amplification of local magnetic energies to
over 100 times the local kinetic energy. While the magnetic wreaths are largely
generated the shearing of axisymmetric poloidal magnetic fields by axisymmetric
rotational shear (the $\Omega$-effect), the loops are amplified to their peak
field strengths before beginning to rise by non-axisymmetric processes. This
further extends and enhances a new paradigm for the generation of emergent
magnetic flux bundles, which we term turbulence-enabled magnetic buoyancy.


title: Higgs Couplings and Electroweak Phase Transition

abstract:
  We argue that extensions of the Standard Model (SM) with a strongly
first-order electroweak phase transition generically predict significant
deviations of the Higgs couplings to gluons, photons, and Z bosons from their
SM values. Precise experimental measurements of the Higgs couplings at the LHC
and at the proposed next-generation facilities will allow for a robust test of
the phase transition dynamics. To illustrate this point, in this paper we focus
on the scenario in which loops of a new scalar field are responsible for the
first-order phase transition, and study a selection of benchmark models with
various SM gauge quantum numbers of the new scalar. We find that the current
LHC measurement of the Higgs coupling to gluons already excludes the
possibility of a first-order phase transition induced by a scalar in a sextet,
or larger, representation of the SU(3)_c. Future LHC experiments (including
HL-LHC) will be able to definitively probe the case when the new scalar is a
color triplet. If the new scalar is not colored, an electron-positron Higgs
factory, such as the proposed ILC or TLEP, would be required to test the nature
of the phase transition. The extremely precise measurement of the
Higgsstrahlung cross section possible at such machines will allow for a
comprehensive and definitive probe of the possibility of a first-order
electroweak phase transition in all models we considered, including the case
when the new scalar is a pure gauge singlet.


title:
Laser cooling of dense atomic gases by collisional redistribution of
  radiation and spectroscopy of molecular dimers in a dense buffer gas
  environment

abstract:
  We study laser cooling of atomic gases by collisional redistribution of
fluorescence. In a high pressure buffer gas regime, frequent collisions perturb
the energy levels of alkali atoms, which allows for the absorption of a far red
detuned irradiated laser beam. Subsequent spontaneous decay occurs close to the
unperturbed resonance frequency, leading to a cooling of the dense gas mixture
by redistribution of fluorescence. Thermal deflection spectroscopy indicates
large relative temperature changes down to and even below room temperature
starting from an initial cell temperature near 700 K. We are currently
performing a detailed analysis of the temperature distribution in the cell. As
we expect this cooling technique to work also for molecular-noble gas mixtures,
we also present initial spectroscopic experiments on alkali-dimers in a dense
buffer gas surrounding.


title:
The low or retrograde spin of the first extragalactic microquasar:
  implications for Blandford-Znajek powering of jets

abstract:
  Transitions to high mass accretion rates in black hole X-ray binaries are
associated with the ejection of powerful, relativistically-moving jets. The
mechanism powering such events is thought to be linked to tapping of the
angular momentum (spin) of the black hole, the rate of accretion through the
disc or some combination of the two. We can attempt to discriminate between
these possibilities by comparing proxies for jet power with spin estimates. Due
to the small number of sources reaching Eddington rates and have therefore been
suggested to act as 'standard candles', there has been much recent debate as to
whether a significant correlation exists between jet power and spin. We perform
continuum fitting to the high-quality, disc-dominated XMM-Newton spectra of the
extragalactic microquasar discovered in M31. Assuming prograde spin, we find
that, for sensible constraints the spin is always very low (a < 0.15 at
3-sigma). When combined with a proxy for jet power derived from the maximum 5
GHz radio luminosity during a bright flaring event, we find that the source
sits well above the previously reported, rising correlation that would indicate
that spin tapping is the dominant mechanism for powering the jets. The notable
exceptions require the inclination to be improbably small or the jet to be very
fast. We investigate whether this could be a by-product of selecting
prograde-only spin, finding that the data statistically favour a substantially
retrograde spin for the same constraints (a < -0.17 at 3-sigma). Although
theoretically improbable, this remarkable finding could be confirmation that
retrograde spin can power such jets via spin-tapping, as has been suggested for
certain radio quasars. In either case this work demonstrates the value of
studying local extragalactic microquasars as a means to better understand the
physics of jet launching.


title: 60Fe-60Ni chronology of core formation in Mars

abstract:
  The timescales of accretion, core formation, and magmatic differentiation in
planetary bodies can be constrained using extinct radionuclide systems.
Experiments have shown that Ni becomes more siderophile with decreasing
pressure, which is reflected in the progressively higher Fe/Ni ratios in the
mantles of Earth, Mars and Vesta. Mars formed rapidly and its mantle has a high
Fe/Ni ratio, so the 60Fe-60Ni decay system (t1/2=2.62 Myr) is well suited to
establish the timescale of core formation in this object. We report new
measurements of 60Ni/58Ni ratios in bulk SNC/martian
(Shergotty-Nakhla-Chassigny) meteorites and chondrites. The difference in
{\epsilon}60Ni values between SNC meteorites and the building blocks of Mars
assumed to be chondritic (55 % ordinary chondrites +45% enstatite chondrites)
is +0.028+/-0.023 (95% confidence interval). Using a model of growth of
planetary embryo, this translates into a time for Mars to have reached ~44 % of
its present size of 1.9(-0.8)(+1.7) Myr with a strict lower limit of 1.2 Myr
after solar system formation, which agrees with a previous estimate based on
182Hf-182W systematics. The presence of Mars when planetesimals were still
being formed may have influenced the formation of chondrules through bow shocks
or by inducing collisions between dynamically excited planetesimals.
Constraints on the growth of large planetary bodies are scarce and this is a
major development in our understanding of the chronology of Mars.


title:
On Linear Regression for Interval-valued Data in
  $\mathcal{K}_{\mathcal{C}}\left(\mathbb{R}\right)$

abstract:
  It has been some time since interval-valued linear regression was
investigated. In this paper, we focus on linear regression for interval-valued
data within the framework of random sets. The model we propose generalizes a
series of existing models. We establish important properties of the model in
the space of compact convex subsets of $\mathbb{R}$, analogous to those for the
classical linear regression. Furthermore, we carry out theoretical
investigations into the least squares estimation that is widely used in the
literature. A simulation study is presented that supports our theorems.
Finally, an application to a climate data set is provided to demonstrate the
applicability of our model.


title:
Inferring properties of small convective cores in main-sequence
  solar-like pulsators

abstract:
  This work concerns the study of the properties of convective cores in
main-sequence models of solar-like pulsators and what information they may hold
about stellar ages. We verified that the maximum absolute frequency derivative
of particular combinations of frequencies, which we name "the slopes", provides
information on the relative size of the discontinuity in the sound-speed
profile at the border of the convectively mixed region. Since the latter is
related to the evolutionary state of stars, we show that for models with masses
above $1.3\,\rm M_\odot$, it may be possible to estimate the fraction of
stellar main-sequence evolution from the slopes. Moreover, for models with
masses below $1.2\,\rm M_\odot$ we verified that it may be possible to use the
slopes to discriminate against models with small amounts of core overshoot.


title: The Preon Sector of the SLq(2) Model and the Binding Problem

abstract:
  There are suggestive experimental indications that the leptons, neutrinos,
and quarks are composite and that their structure is described by the quantum
group SLq(2). Since the hypothetical preons must be very heavy relative to the
masses of the leptons, neutrinos, and quarks, there must be a very strong
binding field to permit these composite particles to form. Unfortunately there
are no experiments direct enough to establish the order of magnitude needed to
make the SLq(2) Lagrangian dynamics quantitative. It is possible, however, to
parametrize the preon masses and interactions that would be necessary to
stabilize the three particle composite representing the leptons, neutrinos, and
quarks. In this note we examine possible parametrizations of the masses and the
interactions of these hypothetical structures. We also note an alternative view
of SLq(2) preons.


title:
The Diederich-Forn{\ae}ss exponent and non-existence of Stein domains
  with Levi-flat boundaries

abstract:
  We study the Diederich-Forn{\ae}ss exponent and relate it to non-existence of
Stein domains with Levi-flat boundaries in complex manifolds. In particular, we
prove that if the Diederich-Forn{\ae}ss exponent of a smooth bounded Stein
domain in an $n$-dimensional complex manifold is $>k/n$, then it has a boundary
point at which the Levi-form has rank $\ge k$.


title:
The dominant epoch of star formation in the Milky Way formed the thick
  disc

abstract:
  We report the first robust measurement of the Milky Way star formation
history using the imprint left on chemical abundances of long-lived stars. The
formation of the Galactic thick disc occurs during an intense star formation
phase between 9.0 (z~1.5) and 12.5 Gyr (z~4.5) ago and is followed by a dip (at
z~1.1) lasting about 1 Gyr. Our results imply that the thick disc is as massive
as the Milky Way's thin disc, suggesting a fundamental role of this component
in the genesis of our Galaxy, something that had been largely unrecognized.
This new picture implies that huge quantities of gas necessary to feed the
building of the thick disc must have been present at these epochs, in
contradiction with the long-term infall assumed by chemical evolution models in
the last two decades. These results allow us to fit the Milky Way within the
emerging features of the evolution of disc galaxies in the early Universe.


title: Algebraic degrees of stretch factors in mapping class groups

abstract:
  We explicitly construct pseudo-Anosov maps on the closed surface of genus $g$
with orientable foliations whose stretch factor $\lambda$ is a Salem number
with algebraic degree $2g$. Using this result, we show that there is a
pseudo-Anosov map whose stretch factor has algebraic degree $d$, for each
positive even integer $d$ such that $d \leq g$.


title: E(B-V), N(H I) and N(H_2)

abstract:
  We consider the structure of the N(H I) - E(B-V) relationship when H I is
measured in the 21 cm radio line and \EBV\ is defined by far-IR dust-derived
measures. We derive reddening-dependent corrections to N(H I) based on
interferometric absorption measurements over the past 30 years that follow a
single power-law relationship $\int \tau(H I) dv = 14.07 ~\kms\ $\EBV$^{1.074}$
at 0.02 $\la$ \EBV\ $\la$ 3 mag. Corrections to 21cm line-derived H I column
densities are too small to have had any effect on the ratio N(H I)/\EBV\ $= 8.3
\times 10^{21}\pcc$ mag$^{-1}$ we derived at 0.015 $\la$ \EBV\ $\la$ 0.075 mag
and \absb\ $\ge$ 20\degr; they are also too small to explain the break in the
slope of the N(H I) - \EBV\ relation at \EBV\ $\ga$ 0.1 mag that we
demonstrated around the Galaxy at \absb $\ge 20$\degr. The latter must
therefore be attributed to the onset of \HH-formation and we show that models
of \HH\ formation in a low density diffuse molecular gas can readily explain
the inflected N(H I)- \EBV\ relationship. Below \absb\ = 20\degr\ N(H I)/\EBV\
measured at 0.015 $\la$ \EBV\ $\la$ 0.075 mag increases steadily down to \absb\
= 8\degr\ where sightlines with small \EBV\ no longer occur.
  By contrast, the ratio N(H I)/\EBV\ measured over all \EBV\ declines to N(H
I)/\EBV\ $= 5-6 \times 10^{21}\pcc$ mag$^{-1}$ at \absb\ $\la 30$\degr, perhaps
providing an explanation of the difference between our results and the
gas/reddening ratios measured previously using stellar spectra.


title: Comments On Torsion and MacDowell-Mansouri gravity

abstract:
  Starting with the MacDowell-Mansouri formulation of gravity with a $SO(4,1)$
gauge group, we introduce new parameters into the action to include the
non-dynamical Holst term, and the topological Nieh-Yan and Pontryagin classes.
Then, we consider the new parameters as fields and analyze the solutions coming
from their equations of motion. The new fields introduce torsional
contributions to the theory that modify Einstein's equations.


title: Dynamics of a first order transition to an absorbing state

abstract:
  A granular system confined in a quasi two-dimensional box that is vertically
vibrated can transit to an absorbing state in which all particles bounce
vertically in phase with the box, with no horizontal motion. In principle, this
state can be reached for any density lower than the one corresponding to one
complete monolayer, which is then the critical density. Below this critical
value, the transition to the absorbing state is of first order, with long
metastable periods, followed by rapid transitions driven by homogeneous
nucleation. Molecular dynamics simulations and experiments show that there is a
dramatic increase on the metastable times far below the critical density; in
practice, it is impossible to observe spontaneous transitions close to the
critical density. This peculiar feature is a consequence of the non-equilibrium
nature of this first order transition to the absorbing state. A Ginzburg-Landau
model, with multiplicative noise, describes qualitatively the observed
phenomena and explains the macroscopic size of the critical nuclei. The nuclei
become of small size only close to a second critical point where the active
phase becomes unstable via a saddle node bifurcation. It is only close to this
second critical point that experiments and simulations can evidence spontaneous
transitions to the absorbing state while the metastable times grow dramatically
moving away from it.


title: Computing for the Energy Frontier: Snowmass Study 2013

abstract:
  The Contribution for the Computing for the Energy Frontier as part of the
Snowmass study is discussed.


title: Tunneling times and bremsstrahlung in alpha decay

abstract:
  A semi-classical model based on quantum time concepts is presented for the
evaluation of bremsstrahlung emission probabilities in alpha decay of nuclei.
The contribution to the bremsstrahlung emission from the different regions in
tunneling is investigated using realistic double folded nuclear and Coulomb
potentials. Within this model, the contribution from the radiation emitted in
front of the barrier before tunneling is much larger than that while leaving
the barrier. A comparison with the data on $^{210}$Po shows that the results
are sensitive to the nuclear potential and the rectangular well used in many of
the quantum mechanical approaches can even give qualitatively different
results.


title:
Robust Large Scale Non-negative Matrix Factorization using Proximal
  Point Algorithm

abstract:
  A robust algorithm for non-negative matrix factorization (NMF) is presented
in this paper with the purpose of dealing with large-scale data, where the
separability assumption is satisfied. In particular, we modify the Linear
Programming (LP) algorithm of [9] by introducing a reduced set of constraints
for exact NMF. In contrast to the previous approaches, the proposed algorithm
does not require the knowledge of factorization rank (extreme rays [3] or
topics [7]). Furthermore, motivated by a similar problem arising in the context
of metabolic network analysis [13], we consider an entirely different regime
where the number of extreme rays or topics can be much larger than the
dimension of the data vectors. The performance of the algorithm for different
synthetic data sets are provided.


title: Free divisors versus stability and coincidence thresholds

abstract:
  We show that there is an unexpected relation between free divisors and
stability and coincidence thresholds for projective hypersurfaces.


title:
Two-loop electroweak threshold corrections to the bottom and top Yukawa
  couplings

abstract:
  We study the relationship between the $\overline{\mathrm{MS}}$ Yukawa
coupling and the pole mass for the bottom and top quarks at the two-loop
electroweak order ${\cal O}(\alpha^2)$ in the gaugeless limit of the standard
model. We also consider the $\overline{\mathrm{MS}}$ to pole mass relationships
at this order, which include tadpole contributions to ensure the gauge
independence of the $\overline{\mathrm{MS}}$ masses. In order to suppress
numerically large tadpole contributions, we propose a redefinition of the
running heavy-quark mass in terms of the $\overline{\mathrm{MS}}$ Yukawa
coupling. We also present $\Delta r$ in the $\overline{\mathrm{MS}}$ scheme at
${\cal O}(\alpha^2)$ in the gaugeless limit. As an aside, we also list the
exact two-loop expression for the mass counterterms of the bottom and top
quarks.


title:
Sources of Variability in Alpha Emissivity Measurements at LA and ULA
  Levels, a Multicenter Study

abstract:
  Alpha emissivity measurements are important in the semiconductor industry for
assessing the suitability of materials for use in production processes. A
recently published round-robin study that circulated the same samples to
several alpha counting centers showed wide center-to-center variations in
measured alpha emissivity. A separate analysis of these results hypothesized
that much of the variation might arise from differences in sample-to-entrance
window separations. XIA recently introduced an ultra low background counter,
the UltraLo-1800 (UltraLo), that operates in a fundamentally different manner
from the proportional counters used at most of the centers in the original
study. In particular, by placing the sample within the counting volume, it
eliminates the sample-to-entrance window separation issue noted above, and so
offers an opportunity to test this hypothesis. In this work we briefly review
how the UltraLo operates and describe a new round-robin study conducted
entirely on UltraLo instruments using a set of standard samples that included
two samples used in the original study. This study shows that, for LA (Low
Alpha between 2 and 50 alpha/khr-cm$^2$) sample measurements, the only
remaining site-to-site variations were due to counting statistics. Variations
in ULA (Ultra-Low Alpha < 2 alpha/khr-cm$^2$) sample measurements were reduced
three-fold, compared to the earlier study, with the measurements suggesting
that residual activity variations now primarily arise from site-to-site
differences in the cosmogenic background.


title: Spectroscopic signatures of crystal momentum fractionalization

abstract:
  We consider gapped Z2 spin liquids, where spinon quasiparticles may carry
fractional quantum numbers of space group symmetry. In particular, spinons can
carry fractional crystal momentum. We show that such quantum number
fractionalization has dramatic, spectroscopically accessible consequences,
namely enhanced periodicity of the two-spinon density of states in the
Brillouin zone, which can be detected via inelastic neutron scattering. This
effect is a sharp signature of certain topologically ordered spin liquids and
other symmetry enriched topological phases. Considering square lattice space
group and time reversal symmetry, we show that exactly four distinct types of
spectral periodicity are possible.


title:
Superparamagnetic iron oxide polyacrylic acid coated {\gamma}-Fe2O3
  nanoparticles does not affect kidney function but causes acute effect on the
  cardiovascular function in healthy mice

abstract:
  This study describes the distribution of intravenously injected polyacrylic
acid (PAA) coated {\gamma}-Fe2O3 NPs (10 mg kg-1) at the organ, cellular and
subcellular levels in healthy BALB/cJ mice and in parallel addresses the
effects of NP injection on kidney function, blood pressure and vascular
contractility. Magnetic resonance imaging (MRI) and transmission electron
microscopy (TEM) showed accumulation of NPs in the liver within 1h after
intravenous infusion, accommodated by intracellular uptake in endothelial and
Kupffer cells with subsequent intracellular uptake in renal cells, particularly
the cytoplasm of the proximal tubule, in podocytes and mesangial cells. The
renofunctional effects of NPs were evaluated by arterial acid-base status and
measurements of glomerular filtration rate (GFR) after instrumentation with
chronically indwelling catheters. Arterial pH was 7.46 and 7.41 in mice 0.5 h
after injections of saline or NP, and did not change over the next 12h. In
addition, the injections of NP did not affect arterial PCO2 or [HCO3-] either.
Twenty-four and 96h after NP injections, the GFR averaged 11.0 and 13.0 ml
min-1 g-1, respectively, values which were statistically comparable with
controls (14.0 and 14.0 ml min-1 g-1). Mean arterial blood pressure (MAP)
decreased 12-24h after NP injections (111 vs 123 min-1) associated with a
decreased contractility of small mesenteric arteries revealed by myography to
characterise endothelial function. In conclusion, our study demonstrates that
accumulation of superparamagnetic iron oxide nanoparticles does not affect
kidney function in healthy mice but temporarily decreases blood pressure.


title:
Multiwavelength modelling the SED of supersoft X-ray sources. I. The
  method and examples

abstract:
  Radiation of supersoft X-ray sources (SSS) dominates both the supersof X-ray
and the far-UV domain. A fraction of their radiation can be reprocessed into
the thermal nebular emission, seen in the spectrum from the near-UV to longer
wavelengths. In the case of symbiotic X-ray binaries (SyXBs) a strong
contribution from their cool giants is indicated in the optical/near-IR. In
this paper I introduce a method of multiwavelength modelling the spectral
energy distribution (SED) of SSSs from the supersoft X-rays to the near-IR with
the aim to determine the physical parameters of their composite spectra. The
method is demonstrated on two extragalactic SSSs, the SyXB RX J0059.1-7505 (LIN
358) in the Small Magellanic Cloud (SMC), RX J0439.8-6809 in the Large
Magellanic Cloud (LMC) and two Galactic SSSs, the classical nova RX
J2030.5+5237 (V1974 Cyg) during its supersoft phase and the classical symbiotic
star RX J1601.6+6648 (AG Dra) during its quiescent phase. The multiwavelength
approach overcomes the problem of the mutual dependence between the
temperature, luminosity and amount of absorption, which appears when only the
X-ray data are fitted.Thus, the method provides an unambiguous solution. It was
found that selection of the model (a blackbody or an atmospheric model) is not
of crucial importance in fitting the global X-ray/IR SED. The multiwavelength
modelling of the SED of SSSs is essential in determining their physical
parameters.


title: The Computational Complexity of Propositional Cirquent Calculus

abstract:
  Introduced in 2006 by Japaridze, cirquent calculus is a refinement of sequent
calculus. The advent of cirquent calculus arose from the need for a deductive
system with a more explicit ability to reason about resources. Unlike the more
traditional proof-theoretic approaches that manipulate tree-like objects
(formulas, sequents, etc.), cirquent calculus is based on circuit-style
structures called cirquents, in which different "peer" (sibling, cousin, etc.)
substructures may share components. It is this resource sharing mechanism to
which cirquent calculus owes its novelty (and its virtues). From its inception,
cirquent calculus has been paired with an abstract resource semantics. This
semantics allows for reasoning about the interaction between a resource
provider and a resource user, where resources are understood in the their most
general and intuitive sense. Interpreting resources in a more restricted
computational sense has made cirquent calculus instrumental in axiomatizing
various fundamental fragments of Computability Logic, a formal theory of
(interactive) computability. The so-called "classical" rules of cirquent
calculus, in the absence of the particularly troublesome contraction rule,
produce a sound and complete system CL5 for Computability Logic. In this paper,
we investigate the computational complexity of CL5, showing it is
$\Sigma_2^p$-complete. We also show that CL5 without the duplication rule has
polynomial size proofs and is NP-complete.


title:
Calibration and data collection protocols for reliable lattice parameter
  values in electron pair distribution function (ePDF) studies

abstract:
  We explore and describe different protocols for calibrating electron pair
distribution function (ePDF) measurements for quantitative studies on
nano-materials. We find the most accurate approach to determine the
camera-length is to use a standard calibration sample of Au nanoparticles from
National Institute of Standards and Technology. Different protocols for data
collection are also explored, as are possible operational errors, to find the
best approaches for accurate data collection for quantitative ePDF studies.


title: Informational Efficiency under Short Sale Constraints

abstract:
  A constrained informationally efficient market is defined to be one whose
price process arises as the outcome of some equilibrium where agents face
restrictions on trade. This paper investigates the case of short sale
constraints, a setting which despite its simplicity, generates new insights. In
particular, it is shown that short sale constrained informationally efficient
markets always admit equivalent supermartingale measures and local martingale
deflators, but not necessarily local martingale measures. And if in addition
some local martingale deflator turns the price process into a true martingale,
then the market is constrained informationally efficient. Examples are given to
illustrate the subtle phenomena that can arise in the presence of short sale
constraints, with particular attention to representative agent equilibria and
the different notions of no arbitrage.


title:
Summary of session A4: Complex and conformal methods in classical and
  quantum gravity

abstract:
  This paper summarises oral contributions to the parallel session {\it Complex
and conformal methods in classical and quantum gravity} which took place during
the 20th International Conference on General Relativity and Gravitation held in
Warsaw in July 2013.


title: The ridgelet transform and quasiasymptotic behavior of distributions

abstract:
  We characterize the quasiasymptotic behavior of distributions in terms of a
Tauberian theorem for ridgelet transforms.


title: Pull-back of quasi-log structures

abstract:
  We prove that the pull-back of a quasi-log scheme by a smooth
quasi-projective morphism has a natural quasi-log structure. We treat an
application to log Fano pairs. This paper also contains a proof of the simple
connectedness of log Fano pairs with only log canonical singularities by Kento
Fujita.


title: The Dynamics Theorem for properly embedded minimal surfaces

abstract:
  In this paper we prove two theorems. The first one is a structure result that
describes the extrinsic geometry of an embedded surface with constant mean
curvature (possibly zero) in a homogeneously regular Riemannian three-manifold,
in any small neighborhood of a point of large almost-maximal curvature. We next
apply this theorem and the Quadratic Curvature Decay Theorem (previously proven
by the same authors in [14]) to deduce compactness, descriptive and
dynamics-type results concerning the space $D(M)$ of non-flat limits under
dilations of any given properly embedded minimal surface $M$ in $\mathbb{R}^3$.


title: Pricing of basket options I

abstract:
  Pricing of high-dimensional options is a deep problem of the Theoretical
Financial Mathematics. In this article we present a new class of L\'{e}vy
driven models of stock markets. In our opinion, any market model should be
based on a transparent and intuitively easily acceptable concept. In our case
this is a linear system of stochastic equations. Our market model is based on
the principle of inheritance, i.e. for the particular choice of parameters it
coincides with known models. Also, the model proposed is effectively
numerically realizable. For the class of models under cosideration, we give an
explicit representations of characteristic functions. This allows us us to
construct a sequence of approximation formulas to price basket options. We show
that our approximation formulas have almost optimal rate of convergence in the
sense of respective n-widths.


title:
A complete classification of the spaces of compact operators on
  C([1,alpha], l_p) spaces, 1<p< infinity

abstract:
  We complete the classification, up to isomorphism, of the spaces of compact
operators on C([1, gamma], l_p) spaces, 1<p< infinity. In order to do this, we
classify, up to isomorphism, the spaces of compact operators {\mathcal K}(E,
F), where E= C([1, lambda], l_p) and F=C([1,xi], l_q) for arbitrary ordinals
lambda and xi and 1< p \leq q< infinity.
  More precisely, we prove that it is relatively consistent with ZFC that for
any infinite ordinals lambda, mu, xi and eta the following statements are
equivalent:
  (a) {\mathcal K}(C([1, lambda], l_p), C([1, xi], l_q)) is isomorphic to
{\mathcal K}(C([1, mu], l_p), C([1, eta], l_q)) .
  (b) lambda and mu have the same cardinality and C([1,xi]) is isomorphic to
C([1, eta]) or there exists an uncountable regular ordinal alpha and 1 \leq m,
n < omega such that C([1, xi]) is isomorphic to C([1, alpha m]) and C([1,eta])
is isomorphic to C([1, alpha n]).
  Moreover, in ZFC, if lambda and mu are finite ordinals and xi and eta are
infinite ordinals then the statements (a) and (b') are equivalent.
  (b') C([1,xi]) is isomorphic to C([1, eta]) or there exists an uncountable
regular ordinal alpha and 1 \leq m, n \leq omega such that C([1, xi]) is
isomorphic to C([1, alpha m]) and C([1,eta]) is isomorphic to C([1, alpha n]).


title:
Robustness of high-fidelity Rydberg gates with single-site
  addressability

abstract:
  Controlled phase (CPHASE) gates can in principle be realized with trapped
neutral atoms by making use of the Rydberg blockade. Achieving the ultra-high
fidelities required for quantum computation with such Rydberg gates is however
compromised by experimental inaccuracies in pulse amplitudes and timings, as
well as by stray fields that cause fluctuations of the Rydberg levels. We
report here a comparative study of analytic and numerical pulse sequences for
the Rydberg CPHASE gate that specifically examines the robustness of the gate
fidelity with respect to such experimental perturbations. Analytical pulse
sequences of both simultaneous and stimulated Raman adiabatic passage (STIRAP)
are found to be at best moderately robust under these perturbations. In
contrast, optimal control theory is seen to allow generation of numerical
pulses that are inherently robust within a predefined tolerance window. The
resulting numerical pulse shapes display simple modulation patterns and their
spectra contain only one additional frequency beyond the basic resonant Rydberg
gate frequencies. Pulses of such low complexity should be experimentally
feasible, allowing gate fidelities of order 99.90 - 99.99% to be achievable
under realistic experimental conditions.


title:
Angular and Polarization Response of Multimode Sensors with
  Resistive-Grid Absorbers

abstract:
  High sensitivity receiver systems with near ideal polarization sensitivity
are highly desirable for development of millimeter and sub-millimeter radio
astronomy. Multimoded bolometers provide a unique solution to achieve such
sensitivity, for which hundreds of single-mode sensors would otherwise be
required. The primary concern in employing such multimoded sensors for
polarimetery is the control of the polarization systematics. In this paper, we
examine the angular- and polarization- dependent absorption pattern of a thin
resistive grid or membrane, which models an absorber used for a multimoded
bolometer. The result shows that a freestanding thin resistive absorber with a
surface resistivity of \eta/2, where \eta\ is the impedance of free space,
attains a beam pattern with equal E- and H-plane responses, leading to zero
cross polarization. For a resistive-grid absorber, the condition is met when a
pair of grids is positioned orthogonal to each other and both have a
resistivity of \eta/2. When a reflective backshort termination is employed to
improve absorption efficiency, the cross-polar level can be suppressed below
-30 dB if acceptance angle of the sensor is limited to <60degrees. The small
cross-polar systematics have even-parity patterns and do not contaminate the
measurements of odd-parity polarization patterns, for which many of recent
instruments for cosmic microwave background are designed. Underlying symmetry
that suppresses these cross-polar systematics is discussed in detail. The
estimates and formalism provided in this paper offer key tools in the design
consideration of the instruments using the multimoded polarimeters.

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


title: Universal measurability and the Hochschild class of the Chern character

abstract:
  We study notions of measurability for singular traces, and characterise
universal measurability for operators in Dixmier ideals. This measurability
result is then applied to improve on the various proofs of Connes'
identification of the Hochschild class of the Chern character of Dixmier
summable spectral triples.
  The measurability results show that the identification of the Hochschild
class is independent of the choice of singular trace. As a corollary we obtain
strong information on the asymptotics of the eigenvalues of operators naturally
associated to spectral triples (A,H,D) and Hochschild cycles for A.


title: Empirical Patterns in Google Scholar Citation Counts

abstract:
  Scholarly impact may be metricized using an author's total number of
citations as a stand-in for real worth, but this measure varies in
applicability between disciplines. The detail of the number of citations per
publication is nowadays mapped in much more detail on the Web, exposing certain
empirical patterns. This paper explores those patterns, using the citation data
from Google Scholar for a number of authors.


title: Spectral Rigidity and Subgroups of Free Groups

abstract:
  A subset $\Sigma \subset F_N$ of the free group of rank $N$ is called
\emph{spectrally rigid} if whenever trees $T, T'$ in Culler-Vogtmann Outer
Space are such that $\| g \|_T = \| g \|_{T'}$ for every $g \in \Sigma$, it
follows that $T = T'$. Results of Smillie, Vogtmann, Cohen, Lustig, and Steiner
prove that (for $N \geq 2$) no finite subset of $F_N$ is spectrally rigid in
$F_N$. We prove that if $\{ H_i \}_{i=1}^k$ is a finite collection of
subgroups, each of infinite index, and $g_i \in F_N$, then $\cup_{i=1}^k g_i
H_i$ is not spectrally rigid in $F_N$. Taking $H_i = 1$, we recover the results
about finite sets. We also prove that any coset of a nontrivial normal subgroup
$H \lhd F_N$ is spectrally rigid.


title: Optimal Subharmonic Entrainment

abstract:
  For many natural and engineered systems, a central function or design goal is
the synchronization of one or more rhythmic or oscillating processes to an
external forcing signal, which may be periodic on a different time-scale from
the actuated process. Such subharmonic synchrony, which is dynamically
established when N control cycles occur for every M cycles of a forced
oscillator, is referred to as N:M entrainment. In many applications,
entrainment must be established in an optimal manner, for example by minimizing
control energy or the transient time to phase locking. We present a theory for
deriving inputs that establish subharmonic N:M entrainment of general nonlinear
oscillators, or of collections of rhythmic dynamical units, while optimizing
such objectives. Ordinary differential equation models of oscillating systems
are reduced to phase variable representations, each of which consists of a
natural frequency and phase response curve. Formal averaging and the calculus
of variations are then applied to such reduced models in order to derive
optimal subharmonic entrainment waveforms. The optimal entrainment of a
canonical model for a spiking neuron is used to illustrate this approach, which
is readily extended to arbitrary oscillating systems.


title: Galactic chemical evolution revisited

abstract:
  Standard chemical evolution models based on long-term infall are affected by
a number of problems, evidenced by the analysis of the most recent data. Among
these: (1) models rely on the local metallicity distribution, assuming its
shape is valid for the entire Galaxy, which it is not; (2) they assume that the
solar vicinity abundance patterns resulted from a unique chemical evolution,
which it does not; (3) they assume the disk is a single structure with chemical
properties that are a smooth function of the distance to the galactic center,
which it is not. Moreover, new results point to a thick disk being as massive
as the thin disk, leading to a change of paradigm in the way we see the
formation of these structures. I discuss these various issues, and, commenting
on Snaith et al. (2014), how a closed box model offers an interesting
approximation to the galactic chemical evolution, by providing the conditions
in which large amounts of gas are available in the disk at high redshift. The
novel way presented in Snaith et al. (2014) to derive SFH from stellar
abundances is also discussed, providing a measurement of the SFH of old
populations that is valid for the entire Galaxy. The derived SFH shows that the
formation of the thick disk has been the dominant epoch of star formation in
our Galaxy.


title: Median eigenvalues and the HOMO-LUMO index of graphs

abstract:
  Motivated by the problem about HOMO-LUMO separation that arises in
mathematical chemistry, Fowler and Pisanski introduced the notion of the
HL-index which measures how large in absolute value may be the median
eigenvalues of a graph. In this note we provide rather tight lower and upper
bounds on the maximum value of the HL-index among all graphs with given average
degree. In particular, we determine the exact value of this parameter when
restricted to chemically relevant graphs, i.e.\ graphs of maximum degree $3$,
and thus answer a question of Fowler and Pisanski. The proof provides
additional insight about eigenvalue distribution of large subcubic graphs.


title: On Sharp Constants for Dual Segal--Bargmann $L^p$ Spaces

abstract:
  We study dilated holomorphic $L^p$ space of Gaussian measures over
$\mathbb{C}^n$, denoted $\mathcal{H}_{p,\alpha}^n$ with variance scaling
parameter $\alpha>0$. The duality relations $(\mathcal{H}_{p,\alpha}^n)^\ast
\cong \mathcal{H}_{p',\alpha}$ hold with $\frac{1}{p}+\frac{1}{p'}=1$, but not
isometrically. We identify the sharp lower constant comparing the norms on
$\mathcal{H}_{p',\alpha}$ and $(\mathcal{H}_{p,\alpha}^n)^\ast$, and provide
upper and lower bounds on the sharp upper constant. We prove several suggestive
partial results on the sharpness of the upper constant. One of these partial
results leads to a sharp bound on each Taylor coefficient of a function in the
Fock space for $n=1$.


title: Nonparametric 3D map of the IGM using the Lyman-alpha forest

abstract:
  Visualizing the high-redshift Universe is difficult due to the dearth of
available data; however, the Lyman-alpha forest provides a means to map the
intergalactic medium at redshifts not accessible to large galaxy surveys.
Large-scale structure surveys, such as the Baryon Oscillation Spectroscopic
Survey (BOSS), have collected quasar (QSO) spectra that enable the
reconstruction of HI density fluctuations. The data fall on a collection of
lines defined by the lines-of-sight (LOS) of the QSO, and a major issue with
producing a 3D reconstruction is determining how to model the regions between
the LOS. We present a method that produces a 3D map of this relatively
uncharted portion of the Universe by employing local polynomial smoothing, a
nonparametric methodology. The performance of the method is analyzed on
simulated data that mimics the varying number of LOS expected in real data, and
then is applied to a sample region selected from BOSS. Evaluation of the
reconstruction is assessed by considering various features of the predicted 3D
maps including visual comparison of slices, PDFs, counts of local minima and
maxima, and standardized correlation functions. This 3D reconstruction allows
for an initial investigation of the topology of this portion of the Universe
using persistent homology.


title:
Multi-frequency study of a new Fe-rich supernova remnant in the Large
  Magellanic Cloud, MCSNR J0508-6902

abstract:
  We present a detailed radio, X-ray and optical study of a newly discovered
Large Magellanic Cloud (LMC) supernova remnant (SNR) which we denote MCSNR
J0508-6902. Observations from the Australian Telescope Compact Array (ATCA) and
the $\textit{XMM-Newton}$ X-ray observatory are complemented by deep H$\alpha$
images and Anglo Australian Telescope AAOmega spectroscopic data to study the
SNR shell and its shock-ionisation. Archival data at other wavelengths are also
examined. The remnant follows a filled-in shell type morphology in the
radio-continuum and has a size of $\sim$74 pc $\times$ 57 pc at the LMC
distance. The X-ray emission exhibits a faint soft shell morphology with
Fe-rich gas in its interior $-$ indicative of a Type Ia origin. The remnant
appears to be mostly dissipated at higher radio-continuum frequencies leaving
only the south-eastern limb fully detectable while in the optical it is the
western side of the SNR shell that is clearly detected. The best-fit
temperature to the shell X-ray emission ($kT = 0.41^{+0.05}_{-0.06}$ keV) is
consistent with other large LMC SNRs. We determined an O/Fe ratio of $<21$ and
an Fe mass of 0.5-1.8$~M_{\odot}$ in the interior of the remnant, both of which
are consistent with the Type Ia scenario. We find an equipartition magnetic
field for the remnant of $\sim$28 $\mu$G, a value typical of older SNRs and
consistent with other analyses which also infer an older remnant.


title: Self-avoiding quantum walks

abstract:
  Quantum walks exhibit many unique characteristics compared to classical
random walks. In the classical setting, self-avoiding random walks have been
studied as a variation on the usual classical random walk. Classical
self-avoiding random walks have found numerous applications, most notably in
the modeling of protein folding. We consider the analogous problem in the
quantum setting. We complement a quantum walk with a memory register that
records where the walker has previously resided. The walker is then able to
avoid returning back to previously visited sites. We parameterise the strength
of the memory recording and the strength of the memory back-action on the
walker's motion, and investigate their effect on the dynamics of the walk. We
find that by manipulating these parameters the walk can be made to reproduce
ideal quantum or classical random walk statistics, or a plethora of more
elaborate diffusive phenomena. In some parameter regimes we observe a close
correspondence between classical self-avoiding random walks and the quantum
self-avoiding walk.


title:
Homological face-width condition forcing $K_6$-minors in graphs on
  surfaces

abstract:
  It is proved that every graph embedded on a (non-spherical) surface with
non-separating face-width at least $7$ contains a minor isomorphic to $K_6$. It
is also shown that face-width four yields the same conclusion for graphs on the
projective plane.


title:
Persistent Optically Induced Magnetism in Oxygen-Deficient Strontium
  Titanate

abstract:
  Strontium titanate (SrTiO$_3$) is a foundational material in the emerging
field of complex oxide electronics. While its electronic and optical properties
have been studied for decades, SrTiO$_3$ has recently become a renewed
materials research focus catalyzed in part by the discovery of magnetism and
superconductivity at interfaces between SrTiO$_3$ and other oxides. The
formation and distribution of oxygen vacancies may play an essential but
as-yet-incompletely understood role in these effects. Moreover, recent
signatures of magnetization in gated SrTiO$_3$ have further galvanized interest
in the emergent properties of this nominally nonmagnetic material. Here we
observe an optically induced and persistent magnetization in oxygen-deficient
SrTiO$_{3-\delta}$ using magnetic circular dichroism (MCD) spectroscopy and
SQUID magnetometry. This zero-field magnetization appears below ~18K, persists
for hours below 10K, and is tunable via the polarization and wavelength of
sub-bandgap (400-500nm) light. These effects occur only in oxygen-deficient
samples, revealing the detailed interplay between magnetism, lattice defects,
and light in an archetypal oxide material.


title: Skew in Parallel Query Processing

abstract:
  We study the problem of computing a conjunctive query q in parallel, using p
of servers, on a large database. We consider algorithms with one round of
communication, and study the complexity of the communication. We are especially
interested in the case where the data is skewed, which is a major challenge for
scalable parallel query processing. We establish a tight connection between the
fractional edge packings of the query and the amount of communication, in two
cases. First, in the case when the only statistics on the database are the
cardinalities of the input relations, and the data is skew-free, we provide
matching upper and lower bounds (up to a poly log p factor) expressed in terms
of fractional edge packings of the query q. Second, in the case when the
relations are skewed and the heavy hitters and their frequencies are known, we
provide upper and lower bounds (up to a poly log p factor) expressed in terms
of packings of residual queries obtained by specializing the query to a heavy
hitter. All our lower bounds are expressed in the strongest form, as number of
bits needed to be communicated between processors with unlimited computational
power. Our results generalizes some prior results on uniform databases (where
each relation is a matching) [4], and other lower bounds for the MapReduce
model [1].


title: Incidence theory and restriction estimates

abstract:
  We investigate the interplay between the discrete restriction phenomenon and
incidence theory. Two angles are explored. One is a refinement of the machinery
developed by Thomas Wolff, which when combined with a recent subcritical
estimate of Bourgain leads to new Strichartz estimates for irrational tori. The
other one connects various additive energies with the Szemer\'edi-Trotter
Theorem. The combination of the two approaches recovers the best known
Strichartz estimates for the classical torus in dimensions $n\ge 3$, without
any appeal to number theory.


title:
A Fast Algorithm for the Inversion of Quasiseparable Vandermonde-like
  Matrices

abstract:
  The results on Vandermonde-like matrices were introduced as a generalization
of polynomial Vandermonde matrices, and the displacement structure of these
matrices was used to derive an inversion formula. In this paper we first
present a fast Gaussian elimination algorithm for the polynomial
Vandermonde-like matrices. Later we use the said algorithm to derive fast
inversion algorithms for quasiseparable, semiseparable and well-free
Vandermonde-like matrices having $\mathcal{O}(n^2)$ complexity. To do so we
identify structures of displacement operators in terms of generators and the
recurrence relations(2-term and 3-term) between the columns of the basis
transformation matrices for quasiseparable, semiseparable and well-free
polynomials. Finally we present an $\mathcal{O}(n^2)$ algorithm to compute the
inversion of quasiseparable Vandermonde-like matrices.


title:
A Wideband Polarization Survey of the Extragalactic Sky at 2-4 GHz: A
  Science White Paper for the VLA Sky Survey

abstract:
  A VLA Sky Survey of the extragalactic sky at S band (2-4 GHz) with
polarization information can uniquely probe the magneto-ionic medium in a wide
range of astrophysical environments over cosmic time. For a shallow all-sky
survey, we expect to detect over 4 million sources in total intensity $>$ 0.45
mJy beam$^{-1}$ and over 2.2$\times$10$^5$ sources in polarized intensity. With
these new observations, we expect to discover new classes of polarized radio
sources in very turbulent astrophysical environments and those with extreme
values of Faraday depth. Moreover, by determining reliable Faraday depths and
by modeling depolarization effects, we can derive properties of the
magneto-ionic medium associated with AGNs, absorption line systems and
galaxies, addressing the following unresolved questions: (1) What is the
covering fraction, the degree of turbulence and the origin of absorption line
systems? (2) What is the thermal content in AGNs and radio galaxies? (3) How do
AGNs and galaxies evolve over cosmic time? (4) What causes the increase in
percentage polarization with decreasing flux densities at the low flux density
end of the polarized source count? (5) What is the growth rate of large-scale
magnetic fields in galaxies?


title: Equivalent relaxations of optimal power flow

abstract:
  Several convex relaxations of the optimal power flow (OPF) problem have
recently been developed using both bus injection models and branch flow models.
In this paper, we prove relations among three convex relaxations: a
semidefinite relaxation that computes a full matrix, a chordal relaxation based
on a chordal extension of the network graph, and a second-order cone relaxation
that computes the smallest partial matrix. We prove a bijection between the
feasible sets of the OPF in the bus injection model and the branch flow model,
establishing the equivalence of these two models and their second-order cone
relaxations. Our results imply that, for radial networks, all these relaxations
are equivalent and one should always solve the second-order cone relaxation.
For mesh networks, the semidefinite relaxation is tighter than the second-order
cone relaxation but requires a heavier computational effort, and the chordal
relaxation strikes a good balance. Simulations are used to illustrate these
results.


title:
Modified spectral parameter power series representations for solutions
  of Sturm-Liouville equations and their applications

abstract:
  Spectral parameter power series (SPPS) representations for solutions of
Sturm-Liouville equations proved to be an efficient practical tool for solving
corresponding spectral and scattering problems. They are based on a computation
of recursive integrals, sometimes called formal powers. In this paper new
relations between the formal powers are presented which considerably improve
and extend the application of the SPPS method. For example, originally the SPPS
method at a first step required to construct a nonvanishing (in general, a
complex-valued) particular solution corresponding to the zero-value of the
spectral parameter. The obtained relations remove this limitation.
Additionally, equations with "nasty" Sturm-Liouville coefficients $1/p$ or $r$
can be solved by the SPPS method.
  We develop the SPPS representations for solutions of Sturm-Liouville
equations of the form $$ (p(x)u')'+q(x)u=\sum_{k=1}^N \lambda^k R_k[u], \quad
x\in(a,b)$$ where $R_k[u] :=r_k(x)u+s_k(x)u'$, $k=1,\ldots N$, the
complex-valued functions $p$, $q$, $r_k$, $s_k$ are continuous on the finite
segment $[a,b]$.
  Several numerical examples illustrate the efficiency of the method and its
wide applicability.


title: Inert Higgs extension of the NMSSM

abstract:
  We introduce one pair of inert Higgs doublets {H_d, H_u} and singlets {N^c,
N}, and consider their couplings with the Higgs doublets of the minimal
supersymmetric standard model (MSSM), W \supset y_N N^c h_u H_d + y_N' N h_d
H_u. We assign extra U(1)_{Z'} gauge charges only to the extra vector-like
superfields, and so all the MSSM superfields remain neutral under the new
U(1)_{Z'}. They can be an extension of the "\lambda term," W \supset \lambda S
h_u h_d in the next-to-MSSM (NMSSM). Due to the U(1)_{Z'}, the maximally
allowed low energy value of y_N can be lifted up to 0.85, avoiding a
Landau-pole (LP) below the grand unification scale. Such colorless vector-like
superfields remarkably enhance the radiative MSSM Higgs mass particularly for
large tan\beta through the y_N term and the corresponding holomorphic soft
term. As a result, the lower bound of \lambda and the upper bound of tan\beta
can be relaxed to disappear from the restricted parameter space of the original
NMSSM, 0.6 < \lambda < 0.7 and 1< tan\beta < 3. Thus, the valid parameter space
significantly expands up to 0 < \lambda < 0.7, 0 < y_N < 0.85, and 2 < tan\beta
< 50, evading the LP problem and also explaining the 126 GeV Higgs mass
naturally.


title: Pseudo-unitary non-self-dual fusion categories of rank 4

abstract:
  A fusion category of rank $4$ has either four self-dual objects or exactly
two self-dual objects. We study fusion categories of rank $4$ with exactly two
self-dual objects, giving nearly a complete classification of those based ring
that admit pseudo-unitary categorification. More precisely, we show that if
$\mathcal{C}$ is such a fusion category, then its Grothendieck ring
$K(\mathcal{C})$ must be one of seven based rings, six of which have know
categorifications. In doing so, we classify all based rings associated with
near-group categories of the group $\mathbb{Z}/3\mathbb{Z}$.


title: DJ-MC: A Reinforcement-Learning Agent for Music Playlist Recommendation

abstract:
  In recent years, there has been growing focus on the study of automated
recommender systems. Music recommendation systems serve as a prominent domain
for such works, both from an academic and a commercial perspective. A
fundamental aspect of music perception is that music is experienced in temporal
context and in sequence. In this work we present DJ-MC, a novel
reinforcement-learning framework for music recommendation that does not
recommend songs individually but rather song sequences, or playlists, based on
a model of preferences for both songs and song transitions. The model is
learned online and is uniquely adapted for each listener. To reduce exploration
time, DJ-MC exploits user feedback to initialize a model, which it subsequently
updates by reinforcement. We evaluate our framework with human participants
using both real song and playlist data. Our results indicate that DJ-MC's
ability to recommend sequences of songs provides a significant improvement over
more straightforward approaches, which do not take transitions into account.


title: From local moment to mixed-valence regime in Ce(1-x)Yb(x)CoIn5 alloys

abstract:
  We investigated the onset of the many-body coherence in the f-orbital single
crystalline alloys Ce(1-x)Yb(x)CoIn5 through thermodynamic and
magneto-transport measurements. Our study shows the evolution of the many-body
electronic state as the Kondo lattice of Ce moments is transformed into an
array of Ce impurities. Specifically, we observe a smooth crossover from the
predominantly localized Ce moment regime to the predominantly itinerant Yb
f-electronic states regime for about 50% of Yb doping. Our analysis of the
residual resistivity data unveils the presence of correlations between Yb ions,
while from our analysis of specific heat data we conclude that for
0.65<x<0.775, ytterbium f-electrons strongly interact with the conduction
electrons while the Ce moments remain completely decoupled. The sub-linear
temperature dependence of resistivity across the whole range of Yb
concentrations suggest the presence of a nontrivial scattering mechanism for
the conduction electrons.


title: Image reconstruction from few views by L0-norm optimization

abstract:
  The L1-norm of the gradient-magnitude images (GMI), which is the well-known
total variation (TV) model, is widely used as regularization in the few views
CT reconstruction. As the L1-norm TV regularization is tending to uniformly
penalize the image gradient and the low-contrast structures are sometimes over
smoothed, we proposed a new algorithm based on the L0-norm of the GMI to deal
with the few views problem. To rise to the challenges introduced by the L0-norm
DGT, the algorithm uses a pseudo-inverse transform of DGT and adapts an
iterative hard thresholding (IHT) algorithm, whose convergence and effective
efficiency have been theoretically proven. The simulation indicates that the
algorithm proposed in this paper can obviously improve the reconstruction
quality.


title: Normal Edge-Transitive Cayley Graphs of Frobenius Groups

abstract:
  A Cayley Graph for a group $G$ is called normal edge-transitive if it admits
an edge-transitive action of some subgroup of the Holomorph of $G$ (the
normaliser of a regular copy of $G$ in $\operatorname{Sym}(G)$). We complete
the classification of normal edge-transitive Cayley graphs of order a product
of two primes by dealing with Cayley graphs for Frobenius groups of such
orders. We determine the automorphism groups of these graphs, proving in
particular that there is a unique vertex-primitive example, namely the flag
graph of the Fano plane.


title:
Quasi-invariance of the stochastic flow associated to It\^o's SDE with
  singular time-dependent drift

abstract:
  In this paper we consider the It\^o SDE
  $$d X_t=d W_t+b(t,X_t)\,d t, \quad X_0=x\in {\mathbb R}^d,$$ where $W_t$ is a
$d$-dimensional standard Wiener process and the drift coefficient
$b:[0,T]\times{\mathbb R}^d\to{\mathbb R}^d$ belongs to $L^q(0,T;L^p({\mathbb
R}^d))$ with $p\geq 2, q>2$ and $\frac dp +\frac 2q<1$. In 2005, Krylov and
R\"ockner \cite{KR05} proved that the above equation has a unique strong
solution $X_t$. Recently it was shown by Fedrizzi and Flandoli \cite{FF13b}
that the solution $X_t$ is indeed a stochastic flow of homeomorphisms on
${\mathbb R}^d$. We prove in the present work that the Lebesgue measure is
quasi-invariant under the flow $X_t$.


title: The Green rings of minimal Hopf quivers

abstract:
  Let $\k$ be a field and $Q$ a minimal Hopf quiver, i.e., a cyclic quiver or
the infinite linear quiver, and let $\rep^{ln}(Q)$ denote the category of
locally nilpotent finite dimensional $\k$-representations of $Q.$ The category
$\rep^{ln}(Q)$ has natural tensor structures induced from graded Hopf
structures on the path coalgebra $\k Q.$ Tensor categories of the form
$\rep^{ln} (Q)$ are an interesting class of tame hereditary pointed tensor
categories which are not finite. The aim of this paper is to compute the
Clebsch-Gordan formulae and Green rings of such tensor categories.


title: A Polynomial Variation on Meinardus' Theorem

abstract:
  We develop a polynomial analogue of Meinardus' Thoerem for bivariate Euler
products and apply it to the study of complex multiplicatively weighted
partitions.


title: On the Weight Distribution of Cyclic Codes with Niho Exponents

abstract:
  Recently, there has been intensive research on the weight distributions of
cyclic codes. In this paper, we compute the weight distributions of three
classes of cyclic codes with Niho exponents. More specifically, we obtain two
classes of binary three-weight and four-weight cyclic codes and a class of
nonbinary four-weight cyclic codes. The weight distributions follow from the
determination of value distributions of certain exponential sums. Several
examples are presented to show that some of our codes are optimal and some have
the best known parameters.


title:
Dynamical Models of Stock Prices Based on Technical Trading Rules Part
  I: The Models

abstract:
  In this paper we use fuzzy systems theory to convert the technical trading
rules commonly used by stock practitioners into excess demand functions which
are then used to drive the price dynamics. The technical trading rules are
recorded in natural languages where fuzzy words and vague expressions abound.
In Part I of this paper, we will show the details of how to transform the
technical trading heuristics into nonlinear dynamic equations. First, we define
fuzzy sets to represent the fuzzy terms in the technical trading rules; second,
we translate each technical trading heuristic into a group of fuzzy IF-THEN
rules; third, we combine the fuzzy IF-THEN rules in a group into a fuzzy
system; and finally, the linear combination of these fuzzy systems is used as
the excess demand function in the price dynamic equation. We transform a wide
variety of technical trading rules into fuzzy systems, including moving average
rules, support and resistance rules, trend line rules, big buyer, big seller
and manipulator rules, band and stop rules, and volume and relative strength
rules. Simulation results show that the price dynamics driven by these
technical trading rules are complex and chaotic, and some common phenomena in
real stock prices such as jumps, trending and self-fulfilling appear naturally.


title: Development of Virtual Accelerator Environment for Beam Diagnostics

abstract:
  For the proper operation of Dalian Compact Light Source (DCLS) linac,
measurement and control of the electron bunch is critical. In order to test
control algorithms and high level physical applications, a virtual accelerator
environment is constructed based on ELEGANT and SDDS toolkit. The required beam
parameter measurement and orbit control tools are verified under this virtual
environment. The design concept and current development status are presented.


title: Black holes in massive conformal gravity

abstract:
  We analyze the classical stability of Schwarzschild black hole in massive
conformal gravity which was recently proposed for another massive gravity
model. This model in the Jordan frame is conformally equivalent to the
Einstein-Weyl gravity in the Einstein frame. The coupled linearized Einstein
equation is decomposed into the traceless and trace equation when one chooses
$6m^2\varphi=\delta R$. Solving the traceless equation exhibits unstable modes
featuring the Gregory-Laflamme $s$-mode instability of five-dimensional black
string, while we find no unstable modes when solving the trace equation. It is
shown that the instability of the black hole in massive conformal gravity
arises from the massiveness where the geometry of extra dimension trades for
mass.


title:
Dynamical Models of Stock Prices Based on Technical Trading Rules Part
  II: Analysis of the Models

abstract:
  In Part II of this paper, we concentrate our analysis on the price dynamical
model with the moving average rules developed in Part I of this paper. By
decomposing the excessive demand function, we reveal that it is the interplay
between trend-following and contrarian actions that generates the price chaos,
and give parameter ranges for the price series to change from divergence to
chaos and to oscillation. We prove that the price dynamical model has an
infinite number of equilibrium points but all these equilibrium points are
unstable. We demonstrate the short-term predictability of the return volatility
and derive the detailed formula of the Lyapunov exponent as function of the
model parameters. We show that although the price is chaotic, the volatility
converges to some constant very quickly at the rate of the Lyapunov exponent.
We extract the formula relating the converged volatility to the model
parameters based on Monte-Carlo simulations. We explore the circumstances under
which the returns show independency and illustrate in details how the
independency index changes with the model parameters. Finally, we plot the
strange attractor and return distribution of the chaotic price model to
illustrate the complex structure and fat-tailed distribution of the returns.


title:
Dynamical Models of Stock Prices Based on Technical Trading Rules Part
  III: Application to Hong Kong Stocks

abstract:
  In Part III of this study, we apply the price dynamical model with big buyers
and big sellers developed in Part I of this paper to the daily closing prices
of the top 20 banking and real estate stocks listed in the Hong Kong Stock
Exchange. The basic idea is to estimate the strength parameters of the big
buyers and the big sellers in the model and make buy/sell decisions based on
these parameter estimates. We propose two trading strategies: (i)
Follow-the-Big-Buyer which buys when big buyer begins to appear and there is no
sign of big sellers, holds the stock as long as the big buyer is still there,
and sells the stock once the big buyer disappears; and (ii) Ride-the-Mood which
buys as soon as the big buyer strength begins to surpass the big seller
strength, and sells the stock once the opposite happens. Based on the testing
over 245 two-year intervals uniformly distributed across the seven years from
03-July-2007 to 02-July-2014 which includes a variety of scenarios, the net
profits would increase 67% or 120% on average if an investor switched from the
benchmark Buy-and-Hold strategy to the Follow-the-Big-Buyer or Ride-the-Mood
strategies during this period, respectively.


title: Plane Partition Polynomial Asymptotics

abstract:
  The plane partition polynomial $Q_n(x)$ is the polynomial of degree $n$ whose
coefficients count the number of plane partitions of $n$ indexed by their
trace. Extending classical work of E.M. Wright, we develop the asymptotics of
these polynomials inside the unit disk using the circle method.


title: Guessing, Mind-changing, and the Second Ambiguous Class

abstract:
  In his dissertation, Wadge defined a notion of guessability on subsets of the
Baire space and gave two characterizations of guessable sets. A set is
guessable iff it is in the second ambiguous class (boldface Delta^0_2), iff it
is eventually annihilated by a certain remainder. We simplify this remainder
and give a new proof of the latter equivalence. We then introduce a notion of
guessing with an ordinal limit on how often one can change one's mind. We show
that for every ordinal alpha, a guessable set is annihilated by alpha
applications of the simplified remainder if and only if it is guessable with
fewer than alpha mind changes. We use guessability with fewer than alpha mind
changes to give a semi-characterization of the Hausdorff difference hierarchy,
and indicate how Wadge's notion of guessability can be generalized to
higher-order guessability, providing characterizations for boldface
Delta^0_alpha for all successor ordinals alpha>1.


title: Efficient unimodality test in clustering by signature testing

abstract:
  This paper provides a new unimodality test with application in hierarchical
clustering methods. The proposed method denoted by signature test (Sigtest),
transforms the data based on its statistics. The transformed data has much
smaller variation compared to the original data and can be evaluated in a
simple proposed unimodality test. Compared with the existing unimodality tests,
Sigtest is more accurate in detecting the overlapped clusters and has a much
less computational complexity. Simulation results demonstrate the efficiency of
this statistic test for both real and synthetic data sets.


title:
Multifractal analysis of dimension spectrum and the set of irregular
  points in non-uniformly hyperbolic systems

abstract:
  We study the multifractal analysis of dimension spectrum for almost additive
potential in a class of one dimensional non-uniformly hyperbolic dynamic
systems and prove that the irregular set has full Hausdroff dimension.


title:
Fabrication of Electronic Fabry-Perot Interferometer in the Quantum Hall
  Regime

abstract:
  A fabrication method for electronic quantum Hall Fabry-Perot interferometers
(FPI) is presented. Our method uses a combination of e-beam lithography and
low-damage dry-etching to produce the FPIs and minimize the excitation of
charged traps or deposition of impurities near the device. Optimization of the
quantum point contacts (QPC) is achieved via systematically varying the etch
depth and monitoring the device resistance between segmented etching sessions.
The etching is stopped when a desired value of resistance is obtained. Finer
control of interference trajectories is obtained by the gate metallized inside
the etched area by e-beam evaporation. Our approach allows for a control of the
delicate potential bending near the quantum well by tuning the confining
potential of the quantum point contacts.


title:
The atmospheric circulation of the super Earth GJ 1214b: Dependence on
  composition and metallicity

abstract:
  We present three-dimensional atmospheric circulation models of GJ 1214b, a
2.7 Earth-radius, 6.5 Earth-mass super Earth detected by the MEarth survey.
Here we explore the planet's circulation as a function of atmospheric
metallicity and atmospheric composition, modeling atmospheres with a low
mean-molecular weight (i.e., H2-dominated) and a high mean-molecular weight
(i.e. water- and CO2-dominated). We find that atmospheres with a low
mean-molecular weight have strong day-night temperature variations at pressures
above the infrared photosphere that lead to equatorial superrotation. For these
atmospheres, the enhancement of atmospheric opacities with increasing
metallicity lead to shallower atmospheric heating, larger day-night temperature
variations and hence stronger superrotation. In comparison, atmospheres with a
high mean-molecular weight have larger day-night and equator-to-pole
temperature variations than low mean-molecular weight atmospheres, but
differences in opacity structure and energy budget lead to differences in jet
structure. The circulation of a water-dominated atmosphere is dominated by
equatorial superrotation, while the circulation of a CO2-dominated atmosphere
is instead dominated by high-latitude jets. By comparing emergent flux spectra
and lightcurves for 50x solar and water-dominated compositions, we show that
observations in emission can break the degeneracy in determining the
atmospheric composition of GJ 1214b. The variation in opacity with wavelength
for the water-dominated atmosphere leads to large phase variations within water
bands and small phase variations outside of water bands. The 50x solar
atmosphere, however, yields small variations within water bands and large phase
variations at other characteristic wavelengths. These observations would be
much less sensitive to clouds, condensates, and hazes than transit
observations.


title:
Molecular Dynamics Simulations of the Nucleation of Water: Determining
  the Sticking Probability and Formation Energy of a Cluster

abstract:
  We performed molecular dynamics (MD) simulations of the nucleation of water
vapor in order to test nucleation theories. Simulations were performed for a
wide range of supersaturation ratios (S = 3-25) and water temperatures
(Tw=300-390K). We obtained the nucleation rates and the formation free energies
of a subcritical cluster from the cluster size distribution. The classical
nucleation theory (CNT) and the modified classical nucleation theory (MCNT)
overestimate the nucleation rates in all cases. The semi-phenomenological (SP)
model, which corrects the MCNT prediction using the second virial coefficient
of a vapor, reproduces the formation free energy of a cluster with the size <
20 to within 10 % and the nucleation rate and cluster size distributions to
within one order of magnitude. The sticking probability of the vapor molecules
to the clusters was also determined from the growth rates of the clusters. The
sticking probability rapidly increases with the supersaturation ratio S, which
is similar to the Lennard-Jones system.


title:
Does Confinement Force Marriage between Two Unwilling Partners?: A Case
  Study of He2@BmNm (m=12, 16)

abstract:
  TThe stability of Ngn@B12N12 and Ngn@B16N16 systems is assessed through a
density functional study and ab initio simulation. Although they are found to
be thermodynamically unstable with respect to the dissociation of individual Ng
atoms and parent cage, ab initio simulation reveals that except Ne2@B12N12 they
are kinetically stable to retain their structures intact throughout the
simulation time (500 fs). The Ne2@B12N12 cage dissociates and the Ne atoms get
separated as the simulation proceeds. The He-He unit undergoes translation,
rotation and vibration inside the cavity of B12N12 and B16N16 cages. Electron
density analysis (Atoms-in-Molecule (AIM)) shows that there is some degree of
covalent character in He-He bond (Wc type) of He2@B12N12. In case of
He2@B16N16, the He-He interaction is mostly of noncovalent type (Wn). In many
cases, especially for the heavier Ng atoms the Ng-N/B bonds are found to be of
covalent type or at least having some degree of covalent character. But Wiberg
bond indices show zero bond order in He-He bond and very low bond order in
cases of Ng-N/B bonds. Energy decomposition analysis (EDA) provides further
insights into the bonding among the Ng atoms and the cage. The change in charge
distribution, radius, hardness, electrophilicity and polarizability implies
that they possess different properties and reactivity from their parent
moieties. The HOMO energies of He2 units in He2@B12N12 and He2@B16N16 are
significantly higher than that in free He atoms. Their kinetic stability and
different calculated properties imply that the He-He interaction and Ng-N/B
interaction may be considered as chemical bonds according to the IUPAC
definition.


title: Spinor and twistor formulations of massless particles with rigidity

abstract:
  The 4-dimensional model of a massless particle with rigidity whose Lagrangian
is proportional to its world-line curvature is reformulated in terms of spinor
and twistor variables. We begin with a first-order Lagrangian that is
equivalent to the original Lagrangian proportional to the extrinsic curvature
of a particle world-line. The first-order Lagrangian is written in terms of
spacetime and spinor variables, leading to a spinor representation of the
Lagrangian. Then its corresponding action is expressed in terms of twistor
variables, leading to the gauged Shirafuji action.


title:
Quadratic Differential Systems on $\mathbb{R}^{3}$ Having a Semisimple
  Derivation

abstract:
  The classification, up to a center-affinity, of the homogeneous quadratic
differential systems defined on $\mathbb{R}^{3}$ that have at least a
semisimple nonsingular derivation, is achieved. It is proved that there exist
four affine-equivalence classes of such systems, only.


title:
Distributed Cloud Computing Environment Enhanced with Capabilities for
  Wide-Area Migration and Replication of Virtual Machines

abstract:
  When a network application is implmented as a virtual machine on a cloud and
is used by a large number of users, the location of the virtual machine should
be selected carefully so that the response time experienced by users is
minimized. As the user population moves and/or increases, the virtual machine
may need to be migrated to a new location or replicated on many locations over
a wide-area network. Virtual machine migration and replication have been
studied extensively but in most cases are limited within a subnetwork to be
able to maintain service continuity. In this paper we introduce a distributed
cloud computing environment which facilitates the migration and replication of
a virtual machine over a wide area network. The mechanism is provided by an
overlay network of smart routers, each of which connects a cooperating data
center to the Internet. The proposed approach is analyzed and compared with
related works


title:
New determination of the D0->K-pi+pi0 and D0->K-pi+pi+pi- coherence
  factors and average strong-phase differences

abstract:
  Measurements of the coherence factors (R_Kpipi0 and R_K3pi) and the average
strong-phase differences (delta^Kpipi0_D and delta^K3pi_D) for the decays D0->
K-pi+pi0 and D0->K-pi+pi+pi- are presented. These parameters are important
inputs to the determination of the unitarity triangle angle gamma in B+/- ->
DK+/- decays, where D designates a D0 or D0bar meson decaying to a common final
state. The measurements are made using quantum correlated DDbar decays
collected by the CLEO-c experiment at the psi(3770) resonance, and augment a
previously published analysis by the inclusion of new events in which the
signal decay is tagged by the mode D-> K0Spi+pi-. The measurements also benefit
from improved knowledge of external inputs, namely the D0D0bar mixing
parameters, r_D^Kpi and several D-meson branching fractions. The measured
values are R_Kpipi0 = 0.82 +- 0.07, delta_D^Kpipi0 = (164+20-14) deg., R_K3pi =
0.32+0.20-0.28 and delta^K3pi_D = (225+21_-78) deg. Consideration is given to
how these measurements can be improved further by using the larger
quantum-correlated data set collected by BESIII.


title:
A Parameterized Complexity Analysis of Bi-level Optimisation with
  Evolutionary Algorithms

abstract:
  Bi-level optimisation problems have gained increasing interest in the field
of combinatorial optimisation in recent years. With this paper, we start the
runtime analysis of evolutionary algorithms for bi-level optimisation problems.
We examine two NP-hard problems, the generalised minimum spanning tree problem
(GMST), and the generalised travelling salesman problem (GTSP) in the context
of parameterised complexity.
  For the generalised minimum spanning tree problem, we analyse the two
approaches presented by Hu and Raidl (2012) with respect to the number of
clusters that distinguish each other by the chosen representation of possible
solutions. Our results show that a (1+1) EA working with the spanning nodes
representation is not a fixed-parameter evolutionary algorithm for the problem,
whereas the global structure representation enables to solve the problem in
fixed-parameter time. We present hard instances for each approach and show that
the two approaches are highly complementary by proving that they solve each
other's hard instances very efficiently.
  For the generalised travelling salesman problem, we analyse the problem with
respect to the number of clusters in the problem instance. Our results show
that a (1+1) EA working with the global structure representation is a
fixed-parameter evolutionary algorithm for the problem.


title:
Visualization of Software and Systems as Support Mechanism for
  Integrated Software Project Control

abstract:
  Many software development organizations still lack support for obtaining
intellectual control over their software development processes and for
determining the performance of their processes and the quality of the produced
products. Systematic support for detecting and reacting to critical process and
product states in order to achieve planned goals is usually missing. One means
to institutionalize measurement on the basis of explicit models is the
development and establishment of a so-called Software Project Control Center
(SPCC) for systematic quality assurance and management support. An SPCC is
comparable to a control room, which is a well known term in the mechanical
production domain. One crucial task of an SPCC is the systematic visualization
of measurement data in order to provide context-, purpose-, and role-oriented
information for all stakeholders (e.g., project managers, quality assurance
managers, developers) during the execution of a software development project.
The article will present an overview of SPCC concepts, a concrete instantiation
that supports goal-oriented data visualization, as well as examples and
experiences from practical applications.


title: Analyzing an Analytical Solution Model for Simultaneous Mobility

abstract:
  Current mobility models for simultaneous mobility have their convolution in
designing simultaneous movement where mobile nodes (MNs) travel randomly from
the two adjacent cells at the same time and also have their complexity in the
measurement of the occurrences of simultaneous handover. Simultaneous mobility
problem incurs when two of the MNs start handover approximately at the same
time. As Simultaneous mobility is different for the other mobility pattern,
generally occurs less number of times in real time; we analyze that a
simplified simultaneous mobility model can be considered by taking only
symmetric positions of MNs with random steps. In addition to that, we simulated
the model using mSCTP and compare the simulation results in different scenarios
with customized cell ranges. The analytical results shows that with the bigger
the cell sizes, simultaneous handover with random steps occurrences become lees
and for the sequential mobility (where initial positions of MNs is
predetermined) with random steps, simultaneous handover is more frequent.


title:
Neutrino Oscillation as a constraint in the dynamics of Pop III Gamma
  Ray Bursts

abstract:
  Population III stars are believed to be rapidly-rotating sources with a mass
range of hundreds to thousand of solar masses. Masses larger than 260 M$_\odot$
are expected to collapse resulting in central rotating Kerr black holes with
large rotation parameter a. Due to particle-antiparticle asymmetry is small, we
use the neutrino effective potential up to order $1/M_W^4$ in a magnetized
plasma at the base of the ejecta to constrain the rotation parameter by means
of neutrino oscillations. Additionally, we investigate the implications in the
magnetic field, temperature and electron asymmetry.


title: Baryon Asymmetry, Dark Matter, and Density Perturbation from PBH

abstract:
  We investigate the consistency of a scenario in which the baryon asymmetry,
dark matters, as well as the cosmic density perturbation are generated
simultaneously through the evaporation of primordial black holes (PBHs). This
scenario can explain the coincidence of the dark matter and the baryon density
of the universe, and is free from the isocurvature perturbation problem. We
show that this scenario predicts the masses of PBHs, right-handed neutrinos and
dark matters, the Hubble scale during inflation, the non-gaussianity and the
running of the spectral index. We also discuss the testability of the scenario
by detecting high frequency gravitational waves from PBHs.


title: Aligning Software-related Strategies in Multi-Organizational Settings

abstract:
  Aligning the activities of an organization with its business goals is a
challenging task that is critical for success. Alignment in a
multi-organizational setting requires the integration of different internal or
external organizational units. The anticipated benefits of multi-organizational
alignment consist of clarified contributions and increased transparency of the
involved organizational units. The GQM+Strategies approach provides mechanisms
for explicitly linking goals and strategies within an organization and is based
on goal-oriented measurement. This paper presents the process and first-hand
experience of applying GQM+Strategies in a multi-organizational setting from
the aerospace industry. Additionally, the resulting GQM+Strategies grid is
sketched and selected parts are discussed. Finally, the results are reflected
on and an overview of future work is given.


title: Polarization and Polarimetry: A Review

abstract:
  Polarization is a basic property of light and is fundamentally linked to the
internal geometry of a source of radiation. Polarimetry complements
photometric, spectroscopic, and imaging analyses of sources of radiation and
has made possible multiple astrophysical discoveries. In this article I review
(i) the physical basics of polarization: electromagnetic waves, photons, and
parameterizations; (ii) astrophysical sources of polarization: scattering,
synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and
Hanle effects, as well as interactions between polarization and matter (like
birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii)
observational methodology: on-sky geometry, influence of atmosphere and
instrumental polarization, polarization statistics, and observational
techniques for radio, optical, and X/gamma wavelengths; and (iv) science cases
for astronomical polarimetry: solar and stellar physics, planetary system
bodies, interstellar matter, astrobiology, astronomical masers, pulsars,
galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic
microwave background radiation.


title:
Estimates for multilinear commutators of generalized fractional integral
  operators on weighted Morrey spaces

abstract:
  Let $L$ be the infinitesimal generator of an analytic semigroup on
$L^2(\mathbb{R}^n)$ with Gaussian kernel bounds, and let $L^{-\alpha/2}$ be the
fractional integrals of $L$ for $0<\alpha<n$. Assume that
$\vec{b}=(b_1,b_2,\cdots,b_m)$ is a finite family of locally integrable
functions, then the multilinear commutators generated by $\vec{b}$ and
$L^{-\alpha/2}$ is defined by \begin{equation*}
L_{\vec{b}}^{-\alpha/2}f=[b_m,\cdots,[b_2,[b_1,L^{-\alpha/2}]],\cdots,]f
\end{equation*} when $b_j\in BMO(w)$, $j=1,2,\cdots,m$, the authors obtain the
boundedness of $L_{\vec{b}}^{-\alpha/2}$ on weighted Morrey spaces.


title:
Model-based Product Quality Evaluation with Multi-Criteria Decision
  Analysis

abstract:
  The ability to develop or evolve software or software-based systems/services
with defined and guaranteed quality in a predictable way is becoming
increasingly important. Essential - though not exclusive - prerequisites for
this are the ability to model the relevant quality properties appropriately and
the capability to perform reliable quality evaluations. Existing approaches for
integrated quality modeling and evaluation are typically either narrowly
focused or too generic and have proprietary ways for modeling and evaluating
quality. This article sketches an ap- proach for modeling and evaluating
quality properties in a uniform way, without losing the ability to build
sufficiently detailed customized models for specific quality properties. The
focus of this article is on the description of a multi-criteria aggregation
mechanism that can be used for the evaluation. In addition, the underlying
quality meta-model, an example application scenario, related work, initial
application results, and an outlook on future research are presented.


title:
Towards Laser-Guide-Stars for Multi-Aperture Interferometry: an
  application to the Hypertelescope

abstract:
  Optical interferometry has been successful at achieving milliarcsecond
resolution on bright stars. Imaging performance can improve greatly by
increasing the number of baselines, which has motivated proposals to build
large (~ 100 m) optical interferometers with tens to hundreds of telescopes. It
is also desirable to adaptively correct atmospheric turbulence to obtain direct
phased images of astrophysical sources. When a natural guide star is not
available, we investigate the feasibility of using a modified laser-guide-star
technique that is suitable for large diluted apertures. The method consists of
using sub-sets of apertures to create an array of artificial stars in the
sodium layer and collecting back-scattered light with the same sub-apertures.
We present some numerical and laboratory simulations that quantify the
requirements and sensitivity of the technique.


title:
A new class of flexible link functions with application to species
  co-occurrence in cape floristic region

abstract:
  Understanding the mechanisms that allow biological species to co-occur is of
great interest to ecologists. Here we investigate the factors that influence
co-occurrence of members of the genus Protea in the Cape Floristic Region of
southwestern Africa, a global hot spot of biodiversity. Due to the binomial
nature of our response, a critical issue is to choose appropriate link
functions for the regression model. In this paper we propose a new family of
flexible link functions for modeling binomial response data. By introducing a
power parameter into the cumulative distribution function (c.d.f.)
corresponding to a symmetric link function and its mirror reflection, greater
flexibility in skewness can be achieved in both positive and negative
directions. Through simulated data sets and analysis of the Protea
co-occurrence data, we show that the proposed link function is quite flexible
and performs better against link misspecification than standard link functions.


title:
Multiple-output support vector regression with a firefly algorithm for
  interval-valued stock price index forecasting

abstract:
  Highly accurate interval forecasting of a stock price index is fundamental to
successfully making a profit when making investment decisions, by providing a
range of values rather than a point estimate. In this study, we investigate the
possibility of forecasting an interval-valued stock price index series over
short and long horizons using multi-output support vector regression (MSVR).
Furthermore, this study proposes a firefly algorithm (FA)-based approach, built
on the established MSVR, for determining the parameters of MSVR (abbreviated as
FA-MSVR). Three globally traded broad market indices are used to compare the
performance of the proposed FA-MSVR method with selected counterparts. The
quantitative and comprehensive assessments are performed on the basis of
statistical criteria, economic criteria, and computational cost. In terms of
statistical criteria, we compare the out-of-sample forecasting using
goodness-of-forecast measures and testing approaches. In terms of economic
criteria, we assess the relative forecast performance with a simple trading
strategy. The results obtained in this study indicate that the proposed FA-MSVR
method is a promising alternative for forecasting interval-valued financial
time series.


title: Semidefinite representations of non-compact convex sets

abstract:
  We consider the problem of the semidefinite representation of a class of
non-compact basic semialgebraic sets. We introduce the conditions of
pointedness and closedness at infinity of a semialgebraic set and show that
under these conditions our modified hierarchies of nested theta bodies and
Lasserre's relaxations converge to the closure of the convex hull of $S$.
Moreover, if the PP-BDR property is satisfied, our theta body and Lasserre's
relaxation are exact when the order is large enough; if the PP-BDR property
does not hold, our hierarchies convergent uniformly to the closure of the
convex hull of $S$ restricted to every fixed ball centered at the origin. We
illustrate through a set of examples that the conditions of pointedness and
closedness are essential to ensure the convergence. Finally, we provide some
strategies to deal with cases where the conditions of pointedness and
closedness are violated.


title: Key Performance Indicators for QOS Assessment in TETRA Networks

abstract:
  Key Performance Indicators (KPIs) are widely used by GSM and UMTS carriers
with the aim of evaluating the network performance and the Quality of Service
(QoS) delivered to users. TETRA networks are basically designed to provide
telecommunication services to Public Safety & Security (PSS) organizations,
thus the compliance of the QoS levels required by these clients is usually
critical. Despite that, the use of KPIs to assess the network performance and
the QoS achieved in TETRA systems is not very common. This paper not only
states the need of monitoring and evaluating these parameters, but also
introduces a set of KPIs which is considered necessary and sufficient in order
to allow TETRA operators to be aware of whether provided services meet the QoS
requirements established by end users.


title: Temporal Graph Traversals: Definitions, Algorithms, and Applications

abstract:
  A temporal graph is a graph in which connections between vertices are active
at specific times, and such temporal information leads to completely new
patterns and knowledge that are not present in a non-temporal graph. In this
paper, we study traversal problems in a temporal graph. Graph traversals, such
as DFS and BFS, are basic operations for processing and studying a graph. While
both DFS and BFS are well-known simple concepts, it is non-trivial to adopt the
same notions from a non-temporal graph to a temporal graph. We analyze the
difficulties of defining temporal graph traversals and propose new definitions
of DFS and BFS for a temporal graph. We investigate the properties of temporal
DFS and BFS, and propose efficient algorithms with optimal complexity. In
particular, we also study important applications of temporal DFS and BFS. We
verify the efficiency and importance of our graph traversal algorithms in real
world temporal graphs.


title: Constrained colouring and $\sigma$-hypergraphs

abstract:
  A constrained colouring or, more specifically, an $(\alpha,\beta)$-colouring
of a hypergraph $H$, is an assignment of colours to its vertices such that no
edge of $H$ contains less than $\alpha$ or more than $\beta$ vertices with
different colours. This notion, introduced by B{\'u}jtas and Tuza, generalises
both classical hypergraph colourings and the more general Voloshin colourings
of hypergraphs. In fact, for $r$-uniform hypergraphs, classical colourings
correspond to $(2,r)$-colourings while an important instance of Voloshin
colourings of $r$-uniform hypergraphs gives $(2, r-1)$-colourings. One
intriguing aspect of all these colourings, not present in classical colourings,
is that $H$ can have gaps in its $(\alpha,\beta)$-spectrum, that is, for $k_1 <
k_2 < k_3$, $H$ would be $(\alpha,\beta)$-colourable using $k_1$ and using
$k_3$ colours, but not using $k_2$ colours.
  In an earlier paper, the first two authors introduced, for $\sigma$ a
partition of $r$, a very versatile type of $r$-uniform hypergraph which they
called $\sigma$-hypergraphs. They showed that, by simple manipulation of the
parameters of a $\sigma$-hypergraph $H$, one can obtain families of hypergraphs
which have $(2,r-1)$-colourings exhibiting various interesting chromatic
properties. They also showed that, if the smallest part of $\sigma$ is at least
2, then $H$ will never have a gap in its $(2,r-1)$-spectrum but, quite
surprisingly, they found examples where gaps re-appear when $\alpha=\beta=2$.
  In this paper we extend many of the results of the first two authors to more
general $(\alpha,\beta)$-colourings, and we study the phenomenon of the
disappearanace and re-appearance of gaps and show that it is not just the
behaviour of a particular example but we place it within the context of a more
general study of constrained colourings of $\sigma$-hypergraphs.


title: Natural realization of large extra dimension in 5D supersymmetric theory

abstract:
  An exponentially large extra dimension can be naturally realized by the
Casimir energy and the gaugino condensation in 5D supersymmetric theory. The
model does not require any hierarchies among the 5D parameters. The key
ingredient is an additional modulus other than the radion, which generically
exists in 5D supergravity. SUSY is broken at the vacuum, which can be regarded
as the Scherk-Schwarz SUSY breaking. We also analyze the mass spectrum and
discuss some phenomenological aspects.


title: Non-trivial $m$-quasi-Einstein metrics on quadratic Lie groups

abstract:
  We call a metric $m$-quasi-Einstein if $Ric_X^m$ (a modification of the
$m$-Bakry-Emery Ricci tensor in terms of a suitable vector field $X$) is a
constant multiple of the metric tensor. It is a generalization of Einstein
metrics which contains Ricci solitons. In this paper, we focus on
left-invariant vector fields and left-invariant Riemannian metrics on quadratic
Lie groups. First we prove that any left-invariant vector field $X$ such that
the left-invariant Riemannian metric on a quadratic Lie group is
$m$-quasi-Einstein is a Killing field. Then we construct infinitely many
non-trivial $m$-quasi-Einstein metrics on solvable quadratic Lie groups $G(n)$
for $m$ finite.


title:
Late-time vacuum phase transitions: Connecting sub-eV scale physics with
  cosmological structure formation

abstract:
  We show that a particular class of postrecombination phase transitions in the
vacuum can lead to localized overdense regions on relatively small scales,
roughly 10^6 to 10^10 M_sun, potentially interesting for the origin of large
black hole seeds and for dwarf galaxy evolution. Our study suggests that this
mechanism could operate over a range of conditions which are consistent with
current cosmological and laboratory bounds. One byproduct of phase transition
bubble-wall decay may be extra radiation energy density. This could provide an
avenue for constraint, but it could also help reconcile the discordant values
of the present Hubble parameter (H_0) and sigma_8 obtained by cosmic microwave
background (CMB) fits and direct observational estimates. We also suggest ways
in which future probes, including CMB considerations (e.g., early dark energy
limits), 21-cm observations, and gravitational radiation limits, could provide
more stringent constraints on this mechanism and the sub-eV scale
beyond-standard-model physics, perhaps in the neutrino sector, on which it
could be based. Late phase transitions associated with sterile neutrino mass
and mixing may provide a way to reconcile cosmological limits and laboratory
data, should a future disagreement arise.