title:
Weak geodesic rays in the space of K\"ahler potentials and the class
  E(X,\omega)

abstract:
  Suppose (X,\omega) is a compact K\"ahler manifold. In the present work we
propose a simple construction for weak geodesic rays in the space of K\"ahler
metrics that seems to be tied together with properties of the class
E(X,\omega). As an application of our construction, we prove a characterization
of E(X,\omega) in terms of envelopes.


title:
Characteristics of the Johari-Goldstein process in rigid asymmetric
  molecules

abstract:
  Molecular dynamics simulations were carried out on a Lennard-Jones binary
mixture of rigid (fixed bond length) diatomic molecules. The translational and
rotational correlation functions, and the corresponding susceptibilities,
exhibit two relaxation processes, the slow structural relaxation (alpha
dynamics) and a higher frequency secondary relaxation. The latter is a
Johari-Goldstein (JG) process, by its definition of involving all parts of the
molecule. It shows several properties characteristic of the JG process - (i)
merging with the alpha relaxation at high temperature; (ii) a change in
temperature-dependence of the relaxation strength on vitrification; (iii) a
separation in frequency from the alpha relaxation that correlates with the
breadth of the structural dispersion; and (iv) sensitivity to volume, pressure,
and physical aging - that can be used to determine whether a secondary
relaxation in a real material is an authentic JG process, rather than trivial
motion involving intramolecular degrees of freedom. The latter has no
connection to the glass transition, whereas the JG relaxation is closely
related to structural relaxation, and thus can provide new insights into the
phenomenon.


title:
Restricting the LSND and MiniBooNE sterile neutrinos with the IceCube
  atmospheric neutrino data

abstract:
  We study oscillations of the high energy atmospheric neutrinos in the Earth
into sterile neutrinos with the eV-scale mass. The MSW resonance and parametric
enhancement of the $\bar{\nu}_\mu\to\bar{\nu}_s$ oscillations lead to
distortion of the zenith angle distribution of the muon-track events which can
be observed by IceCube. Due to matter effect, the IceCube signal depends not
only on the mixing element $U_{\mu 4}$ relevant for LSND and MiniBooNE but also
on $U_{\tau 4}$ and the CP-violating phase $\delta_{24}$. We show that the case
with $U_{\tau 4} = \delta_{24} = 0$ leads to the weakest IceCube signal and
therefore should be used to bound $U_{\mu 4}$. We compute the zenith angle
distributions of the $\nu_\mu-$events for different energy intervals in the
range (0.1 - 10) TeV and find that inclusion of the energy information (binning
in energy) improves the sensitivity to $\nu_s$ drastically. We estimate that
with already collected (during 3 - 4 years) IceCube statistics the bound
$|U_{\mu 4}|^2 < 0.01$ ($99\%$ C.L.) can be established and the mixing required
by LSND and MiniBooNE can be excluded at $(4 - 6) \sigma$ confidence level.


title:
On Poincar\'e-Bendixson Theorem and Non-Trivial Minimal Sets in Planar
  Nonsmooth Vector Fields

abstract:
  In this paper some qualitative and geometric aspects of nonsmooth vector
fields theory are discussed. In the class of nonsmooth systems, that do not
present sliding regions, a Poincar\'e-Bendixson Theorem is presented. A minimal
set in planar Filippov systems not predicted in classical Poincar\'e-Bendixson
theory and whose interior is non-empty is exhibited. The concepts of limit
sets, recurrence and minimal sets for nonsmooth systems are defined and
compared with the classical ones. Moreover some differences between them are
pointed out.


title:
Preparation of $km$-photon concatenated GHZ states for observing
  distinct quantum effects at macroscopic scale

abstract:
  As a class of multipartite entangled states, the multipartite concatenated
GHZ (C-GHZ) states remain superior stability under the influence of
decoherence. We propose two scalable experimental realization of the
multiphoton C-GHZ states based on the entanglers of multiphoton GHZ state.
Given a $km$-photon GHZ state as an input state, if $m$ is odd, one can create
a $km$-photon C-GHZ state. Also, generally, we design a scheme to prepare
$km$-photon C-GHZ states from $km$ single-photon states by using $k$ entanglers
of $m$-photon GHZ state and $k$ $m$-control Toffoli gates.


title:
Local Existence of Strong Solutions to the 3D Zakharov-Kuznestov
  Equation in a Bounded Domain

abstract:
  We consider here the local existence of strong solutions for the
Zakharov-Kuznestov (ZK) equation posed in a limited domain (0,1)_{x}\times(-pi
/2, pi /2)^d, d=1,2. We prove that in space dimensions 2 and 3, there exists a
strong solution on a short time interval, whose length only depends on the
given data. We use the parabolic regularization of the ZK equation to derive
the global and local bounds independent of epsilon for various norms of the
solution. In particular, we derive the local bound of the nonlinear term by a
singular perturbation argument. Then we can pass to the limit and hence deduce
the local existence of strong solutions.


title: On the automorphisms of Hassett's moduli spaces

abstract:
  Let $\overline{\mathcal{M}}_{g,A[n]}$ be the moduli stack parametrizing
weighted stable curves, and let $\overline{M}_{g,A[n]}$ be its coarse moduli
space. These spaces have been introduced by B. Hassett, as compactifications of
$\mathcal{M}_{g,n}$ and $M_{g,n}$ respectively, by assigning rational weights
$A = (a_{1},...,a_{n})$, $0< a_{i} \leq 1$ to the markings. In particular, the
classical Deligne-Mumford compactification arises for $a_1 = ... = a_n = 1$. In
genus zero some of these spaces appear as intermediate steps of the blow-up
construction of $\overline{M}_{0,n}$ developed by M. Kapranov, while in higher
genus they may be related to the LMMP on $\overline{M}_{g,n}$. We compute the
automorphism groups of most of the Hassett's spaces appearing in the Kapranov's
blow-up construction. Furthermore, if $g\geq 1$ we compute the automorphism
groups of all Hassett's spaces. In particular, we prove that if $g\geq 1$ and
$2g-2+n\geq 3$ then the automorphism groups of both
$\overline{\mathcal{M}}_{g,A[n]}$ and $\overline{M}_{g,A[n]}$ are isomorphic to
a subgroup of $S_{n}$ whose elements are permutations preserving the weight
data in a suitable sense.


title:
Genetics of single-cell protein abundance variation in large yeast
  populations

abstract:
  Many DNA sequence variants influence phenotypes by altering gene expression.
Our understanding of these variants is limited by sample sizes of current
studies and by measurements of mRNA rather than protein abundance. We developed
a powerful method for identifying genetic loci that influence protein
expression in very large populations of the yeast Saccharomyes cerevisiae. The
method measures single-cell protein abundance through the use of
green-fluorescent-protein tags. We applied this method to 160 genes and
detected many more loci per gene than previous studies. We also observed closer
correspondence between loci that influence protein abundance and loci that
influence mRNA abundance of a given gene. Most loci cluster at hotspot
locations that influence multiple proteins - in some cases, more than half of
those examined. The variants that underlie these hotspots have profound effects
on the gene regulatory network and provide insights into genetic variation in
cell physiology between yeast strains.


title: Excursions of excited random walks on integers

abstract:
  Several phase transitions for excited random walks on the integers are known
to be characterized by a certain drift parameter delta. For
recurrence/transience the critical threshold is |delta|=1, for ballisticity it
is |delta|=2 and for diffusivity |delta|=4. In this paper we establish a phase
transition at |delta|=3. We show that the expected return time of the walker to
the starting point, conditioned on return, is finite iff |delta|>3. This result
follows from an explicit description of the tail behaviour of the return time
as a function of delta, which is achieved by diffusion approximation of related
branching processes by squared Bessel processes.


title: Secondary characteristic classes and the Euler class

abstract:
  We discuss secondary (and higher) characteristic classes for algebraic vector
bundles with trivial top Chern class. We show that if X is a smooth affine
scheme of dimension d over a field k of finite 2-cohomological dimension (with
char(k) $\neq$ 2) and E is a rank d vector bundle over X, vanishing of the
Chow-Witt theoretic Euler class of E is equivalent to vanishing of its top
Chern class and these higher classes. We then derive some consequences of our
main theorem when k is of small 2-cohomological dimension.


title: Dust properties from GALEX observations of a UV halo around Spica

abstract:
  GALEX has detected ultraviolet halos extending as far as 5$^{\circ}$ around
four bright stars (Murthy et al. (2011)). These halos are produced by
scattering of starlight by dust grains in thin foreground clouds that are not
physically associated with the star. Assuming a simple model consisting of a
single layer of dust in front of the star, Murthy et al.(2011) have been able
to model these halo intensities and constrain the value of the phase function
asymmetry factor $g$ of the scattering grains in the FUV and NUV. However due
to the uncertainty in the dust geometry they could not constrain the albedo. In
this work we have tried to constrain the optical constants and dust geometry by
modeling the UV halo of Spica. Since the halo emission is not symmetric, we
have modeled the Northern and Southern parts of the halo separately. To the
North of Spica, the best-fit albedo is 0.26$\pm$0.1 and $g$ is 0.58$\pm$0.11 in
the FUV at the 90% confidence level. The corresponding limits on the distance
and optical depth ($\tau$) of the dust sheet is 3.65$\pm$1.05 pc and
0.047$\pm$0.006 respectively. However, owing to a complicated dust distribution
to the South of Spica, we were unable to uniquely constrain the dust parameters
in that region. Nevertheless, by assuming the optical constants of the Northern
region and assuming a denser medium, we were able to constrain the distance of
the dust to 9.5$\pm$1.5 pc and the corresponding $\tau$ to 0.04$\pm$0.01.


title: Geometrical crossover in two-body systems in a magnetic field

abstract:
  An algebraic approach is formulated in the harmonic approximation to describe
a dynamics of two-fermion systems, confined in three-dimensional axially
symmetric parabolic potential, in an external magnetic field. The fermion
interaction is considered in the form U_(M)(r)= alpha_(M)r^{-M} (alpha_(M)>0,
M>0). The formalism of a semi-simple Lie group is applied to analyse symmetries
of the considered system. Explicit algebraic expressions are derived in terms
of system's parameters and the magnetic field strength to trace the evolution
of the equilibrium shape. It is predicted that the interplay of classical and
quantum correlations may lead to a quantum shape transition from a lateral to a
vertical localization of fermions in the confined system. The analytical
results demonstrate a good agreement with numerical results for two-electron
quantum dots in the magnetic field, when classical correlations dominate in the
dynamics.

categories: math-ph cond-mat.mes-hall math.MP quant-ph


title:
Noise-assisted Thouless pump in elastically deformable molecular
  junctions

abstract:
  We study a Thouless pump realized with an elastically \textit{deformable
quantum dot} whose center of mass follows a non-linear stochastic dynamics. The
interplay of noise, non-linear effects, dissipation and interaction with an
external time-dependent driving on the pumped charge is fully analyzed. The
results show that the quantum pumping mechanism not only is not destroyed by
the force fluctuations, but it becomes stronger when the forcing signal
frequency is tuned close to the resonance of the vibrational mode. The
robustness of the quantum pump with temperature is also investigated and an
exponential decay of the pumped charge is found when the coupling to the
vibrational mode is present. Implications of our results for
nano-electromechanical systems are also discussed.


title:
Numerical studies of space filling designs: optimization of Latin
  Hypercube Samples and subprojection properties

abstract:
  Quantitative assessment of the uncertainties tainting the results of computer
simulations is nowadays a major topic of interest in both industrial and
scientific communities. One of the key issues in such studies is to get
information about the output when the numerical simulations are expensive to
run. This paper considers the problem of exploring the whole space of
variations of the computer model input variables in the context of a large
dimensional exploration space. Various properties of space filling designs are
justified: interpoint-distance, discrepancy, minimum spanning tree criteria. A
specific class of design, the optimized Latin Hypercube Sample, is considered.
Several optimization algorithms, coming from the literature, are studied in
terms of convergence speed, robustness to subprojection and space filling
properties of the resulting design. Some recommendations for building such
designs are given. Finally, another contribution of this paper is the deep
analysis of the space filling properties of the design 2D-subprojections.


title:
Variable Density Compressed Sensing In MRI. Theoretical vs Heuristic
  Sampling Strategies

abstract:
  The structure of Magnetic Resonance Images (MRI) and especially their
compressibility in an appropriate representation basis enables the application
of the compressive sensing theory, which guarantees exact image recovery from
incomplete measurements. According to recent theoretical conditions on the
reconstruction guarantees, the optimal strategy is to downsample the k-space
using an independent drawing of the acquisition basis entries. Here, we first
bring a novel answer to the synthesis problem, which amounts to deriving the
op- timal distribution (according to a given criterion) from which the data
should be sampled. Then, given that the sparsity hypothesis is not fulfilled in
the k-space center in MRI, we extend this approach by densely sampling this
center and drawing the remaining samples from the optimal distribution. We
compare this theoretical approach to heuristic strategies, and show that the
proposed two-stage process drastically improves reconstruction results on
anatomical MRI.


title: Travelling salesman-based variable density sampling

abstract:
  Compressed sensing theory indicates that selecting a few measurements
independently at random is a near optimal strategy to sense sparse or
compressible signals. This is infeasible in practice for many acquisition
devices that acquire sam- ples along continuous trajectories. Examples include
magnetic resonance imaging (MRI), radio-interferometry, mobile-robot sampling,
... In this paper, we propose to generate continuous sampling trajectories by
drawing a small set of measurements independently and joining them using a
travelling salesman problem solver. Our contribution lies in the theoretical
derivation of the appropriate probability density of the initial drawings.
Preliminary simulation results show that this strategy is as efficient as
independent drawings while being implementable on real acquisition systems.


title:
Eigenfunctions of Unbounded Support for Embedded Eigenvalues of Locally
  Perturbed Periodic Graph Operators

abstract:
  It is known that, if a locally perturbed periodic self-adjoint operator on a
combinatorial or quantum graph admits an eigenvalue embedded in the continuous
spectrum, then the associated eigenfunction is compactly supported--that is, if
the Fermi surface is irreducible, which occurs generically in dimension two or
higher. This article constructs a class of operators whose Fermi surface is
reducible for all energies by coupling several periodic systems. The components
of the Fermi surface correspond to decoupled spaces of hybrid states, and in
certain frequency bands, some components contribute oscillatory hybrid states
(corresponding to spectrum) and other components contribute only exponential
ones. This separation allows a localized defect to suppress the oscillatory
(radiation) modes and retain the evanescent ones, thereby leading to embedded
eigenvalues whose associated eigenfunctions decay exponentially but are not
compactly supported.


title: Bloch sphere colourings and Bell inequalities

abstract:
  We consider here the predictions of quantum theory and local hidden variables
for the correlations obtained by measuring a pair of qubits by projections
defined by randomly chosen axes separated by a given angle \theta. The
predictions of local hidden variable models for projective measurements on
qubits correspond to binary colourings of the Bloch sphere with antipodal
points oppositely coloured. We prove Bell inequalities separating the
predictions of all local hidden variable models from the singlet correlations
predicted by quantum theory for all \theta in the range 0 < \theta < \pi/3. We
raise and explore the possibility of proving stronger Bell inequalities
directly from optimization results on sphere colourings. In particular, we
explore strong and weak forms of the hemispherical colouring maximality
hypothesis (HCMH) that, for a continuous range of \theta > 0, the maximum LHV
anti-correlation is obtained by assigning to each qubit a colouring with one
hemisphere black and the other white. Our results show that hemispherical
colourings are near-optimal for small \theta; we also describe numerical tests
consistent with the HCMH that bound the range of \theta. Finally, we note
proofs of related results for binary colourings of R^n.


title:
What is the role of the meson cloud in the $\Sigma^{*0} \to \gamma
  \Lambda$ and $\Sigma^\ast \to \gamma \Sigma$ decays?

abstract:
  We study the effect of the meson cloud dressing in the octet baryon to
decuplet baryon electromagnetic transitions. Combining the valence quark
contributions from the covariant spectator quark model with those of the meson
cloud estimated based on the flavor SU(3) cloudy bag model, we calculate the
transition magnetic form factors at $Q^2=0$ ($Q^2=-q^2$ and $q$ the
four-momentum transfer), and also the decuplet baryon electromagnetic decay
widths. The result for the $\gamma^\ast \Lambda \to \Sigma^{\ast 0}$ decay
width is in complete agreement with the data, while that for the $\gamma^\ast
\Sigma^+ \to \Sigma^{\ast +}$ is underestimated the data by 1.4 standard
deviations. This achievement may be regarded as a significant advance in the
present theoretical situation.


title: Hedetniemi's conjecture for uncountable graphs

abstract:
  It is proved that in Godel's constructible universe, for every infinite
successor cardinal k, there exist graphs G and H of size and chromatic number
k, for which the tensor product graph (G x H) is countably chromatic.


title: Some remarks about Descartes' rule of signs

abstract:
  What can we deduce about the roots of a real polynomial in one variable by
simply considering the signs of its coefficients? On one hand, we give a
complete answer concerning the positive roots, by proposing a statement of
Descartes' rule of signs which strengthens the available ones while remaining
as elementary and concise as the original. On the other hand, we provide new
kinds of restrictions on the combined numbers of positive and negative roots.


title: Optimal Quantization for Distribution Synthesis

abstract:
  Finite precision approximations of discrete probability distributions are
considered, applicable for distribution synthesis, e.g., probabilistic shaping.
Two algorithms are presented that find the optimal $M$-type approximation $Q$
of a distribution $P$ in terms of the variational distance $| Q-P|_1$ and the
informational divergence $\mathbb{D}(Q| P)$. Bounds on the approximation errors
are derived and shown to be asymptotically tight. Several examples illustrate
that the variational distance optimal approximation can be quite different from
the informational divergence optimal approximation.


title: Plasmon dispersions in simple metals and Heusler compounds

abstract:
  We present a comprehensive study of plasmon dispersions in simple metals and
Heusler compounds based on an accurate ab-initio evaluation of the momentum and
frequency dependent dielectric function in the random-phase approximation.
Using a momentum-dependent tetrahedron method for the computation of the
dielectric function, we extract and analyze "full" and "intraband" plasmon
dispersions: The "full" plasma dispersion is obtained by including all bands,
the intraband plasma dispersion by including only intraband transitions. For
the simple metals silver and alu- minum, we show that the intraband plasmon
dispersion has an unexpected downward slope and is therefore markedly different
from the results of an effective-mass electron-gas model and the full plasmon
dispersion. For the two Heusler compounds Co2FeSi and Co2MnSi, we present
spectra for the dielectric function, their loss functions and plasmon
dispersions. The latter exhibit the same negative intraband plasmon dispersion
as found in the simple metals. We also discuss the influence of spin-mixing on
the plasmon dispersion.


title: Lorentz and CPT violation in the Neutrino Sector

abstract:
  Searches for Lorentz and CPT violation using neutrino oscillations and the
prospects for future tests using neutrino time-of-flight measurements and
beta-decay experiments are presented.


title:
Effect of vortex hotspots on the radio-frequency surface resistance of
  superconductors

abstract:
  We present detailed experimental and theoretical investigations of hotspots
produced by trapped vortex bundles and their effect on the radio-frequency (rf)
surface resistance $R_s$ of superconductors at low temperatures. Our
measurements of $R_s$ combined with the temperature mapping and laser scanning
of a 2.36 mm thick Nb plate incorporated into a 3.3 GHz Nb resonator cavity
cooled by the superfluid He at 2 K, revealed spatial scales and temperature
distributions of hotspots and showed that they can be moved or split by thermal
gradients produced by the scanning laser beam. These results, along with the
observed hysteretic field dependence of $R_s$ which can be tuned by the
scanning laser beam, show that the hotspots in our Nb sample are due to trapped
vortex bundles which contain $\sim 10^6$ vortices spread over regions $\sim
0.1-1$ cm. We calculated the frequency dependence of the rf power dissipated by
oscillating vortex segments trapped between nanoscale pinning centers, taking
into account all bending modes and the nonlocal line tension of the vortex
driven by rf Meissner currents. We also calculated the temperature
distributions caused by trapped vortex hotspots, and suggested a method of
reconstructing the spatial distribution of vortex dissipation sources from the
observed temperature maps. Vortex hotspots can dominate the residual surface
resistance at low temperatures and give rise to a significant dependence of
$R_s$ on the rf field amplitude $H_p$, which can have important implications
for the rf resonating cavities used in particle accelerators and for thin film
structures used in quantum computing and photon detectors.


title: The ASTRI Mini-Array Software System

abstract:
  ASTRI ("Astrofisica con Specchi a Tecnologia Replicante Italiana") is a
Flagship Project financed by the Italian Ministry of Education, University and
Research, and led by INAF, the Italian National Institute of Astrophysics. Main
goals of the ASTRI project are the realization of an end-to-end prototype of a
Small Size Telescope (SST) for the Cherenkov Telescope Array (CTA) in a
dual-mirror configuration (SST-2M) and, subsequently, of a mini-array composed
of a few SST-2M telescopes to be placed at the final CTA Southern Site. Here we
present the main features of the Mini-Array Software System (MASS) that has a
central role in the success of the ASTRI Project and will also serve as a
prototype for the CTA software system. The MASS will provide a set of tools to
prepare an observing proposal, to perform the observations specified therein
(monitoring and controlling all the hardware components of each telescope), to
analyze the acquired data online and to store/retrieve all the data products
to/from the archive.}


title: Localization on Three-Manifolds

abstract:
  We consider supersymmetric gauge theories on Riemannian three-manifolds with
the topology of a three-sphere. The three-manifold is always equipped with an
almost contact structure and an associated Reeb vector field. We show that the
partition function depends only on this vector field, giving an explicit
expression in terms of the double sine function. In the large N limit our
formula agrees with a recently discovered two-parameter family of dual
supergravity solutions. We also explain how our results may be applied to prove
vortex-antivortex factorization. Finally, we comment on the extension of our
results to three-manifolds with non-trivial fundamental group.


title: Reduced models in chemical kinetics via nonlinear data-mining

abstract:
  The adoption of detailed mechanisms for chemical kinetics often poses two
types of severe challenges: First, the number of degrees of freedom is large;
and second, the dynamics is characterized by widely disparate time scales. As a
result, reactive flow solvers with detailed chemistry often become intractable
even for large clusters of CPUs, especially when dealing with direct numerical
simulation (DNS) of turbulent combustion problems. This has motivated the
development of several techniques for reducing the complexity of such kinetics
models, where eventually only a few variables are considered in the development
of the simplified model. Unfortunately, no generally applicable a priori recipe
for selecting suitable parameterizations of the reduced model is available, and
the choice of slow variables often relies upon intuition and experience. We
present an automated approach to this task, consisting of three main steps.
First, the low dimensional manifold of slow motions is (approximately) sampled
by brief simulations of the detailed model, starting from a rich enough
ensemble of admissible initial conditions. Second, a global parameterization of
the manifold is obtained through the Diffusion Map (DMAP) approach, which has
recently emerged as a powerful tool in data analysis/machine learning. Finally,
a simplified model is constructed and solved on the fly in terms of the above
reduced (slow) variables. Clearly, closing this latter model requires
nontrivial interpolation calculations, enabling restriction (mapping from the
full ambient space to the reduced one) and lifting (mapping from the reduced
space to the ambient one). This is a key step in our approach, and a variety of
interpolation schemes are reported and compared. The scope of the proposed
procedure is presented and discussed by means of an illustrative combustion
example.


title: Holographic Schwinger Effect and the Geometry of Entanglement

abstract:
  In this note we point out that the recently proposed bulk dual of an
entangled pair of a quark and an anti-quark corresponds to the Lorentzian
continuation of the tunneling instanton describing Schwinger pair creation in
the dual field theory. This observation supports and further explains the claim
by Jensen & Karch that the bulk dual of an EPR pair is a string with a wormhole
on its world sheet. We suggest that this constitutes an AdS/CFT realization of
the creation of a Wheeler wormhole.


title: On Nash approximation of complex analytic sets in Runge domains

abstract:
  We prove that every complex analytic set X in a Runge domain D can be
approximated by Nash sets on relatively compact subdomains of D. We give a
necessary and sufficient condition for a complex analytic set X to admit a Nash
approximation which coincides with X along its given subsets.


title: One-dimensional Bose-Hubbard model with pure three-body interactions

abstract:
  The extended Bose-Hubbard model with pure three-body local interactions is
studied using the Density Matrix Renormalization Group approach. The shapes of
the first two insulating lobes are discussed, and the values of the critical
tunneling for which the system undergoes the quantum phase transition from
insulating to superfluid phase are predicted. It is shown that stability of
insulating phases, in contrast to the standard Bose-Hubbard model, is enhanced
for larger fillings. It is also shown that, on the tip of the boundary of the
insulating phase, the model under consideration belongs to the
Berenzinskii-Kosterlitz-Thouless universality class.


title:
Prevalence of the sling effect for enhancing collision rates in
  turbulent suspensions

abstract:
  Turbulence facilitates collisions between particles suspended in a turbulent
flow. Two effects have been proposed which can enhance the collision rate at
high turbulence intensities: 'preferential concentration' (a clustering
phenomenon) and the 'sling effect' (arising from the formation of caustic folds
in the phase-space of the suspended particles). We have determined numerically
the collision rate of small heavy particles as a function of their size and
densities. The dependence on particle densities reveals that the enhancement by
turbulence of the collision rate of particles with significant inertia is due
almost entirely to the sling effect.


title: Renormalization of Massless Feynman Amplitudes in Configuration Space

abstract:
  A systematic study of recursive renormalization of Feynman amplitudes is
carried out both in Euclidean and in Minkowski configuration space. For a
massless quantum field theory (QFT) we use the technique of extending associate
homogeneous distributions to complete the renormalization recursion. A
homogeneous (Poincare covariant) amplitude is said to be convergent if it
admits a (unique covariant) extension as a homogeneous distribution. For any
amplitude without subdivergences - i.e. for a Feynman distribution that is
homogeneous off the full (small) diagonal - we define a renormalization
invariant residue. Its vanishing is a necessary and sufficient condition for
the convergence of such an amplitude. It extends to arbitrary - not necessarily
primitively divergent - Feynman amplitudes. This notion of convergence is finer
than the usual power counting criterion and includes cancellation of
divergences.


title: New Cataclysmic Variable 1RXS J015017.0+375614 in Andromeda

abstract:
  We report the discovery of a new cataclysmic variable in MASTER database
which is identical to the faint ROSAT X-ray source 1RXS J015017.0+375614. The
object was observed in outbursts to 14.9m on 2012 Nov. 28 and to 14.3m on 2013
Jan. 07, but not detected in course of the routine real-time search. Analysis
of the archival MASTER data and CRTS light curve shows the large-amplitude
variability from 19.1m at quiescence to 15.4-14.8m in outbursts. The new
variable is most likely a dwarf nova of SU UMa subtype with rather frequent
normal outbursts and occasional superoutbursts.


title: Bootstrapping the O(N) Vector Models

abstract:
  We study the conformal bootstrap for 3D CFTs with O(N) global symmetry. We
obtain rigorous upper bounds on the scaling dimensions of the first O(N)
singlet and symmetric tensor operators appearing in the $\phi_i \times \phi_j$
OPE, where $\phi_i$ is a fundamental of O(N). Comparing these bounds to
previous determinations of critical exponents in the O(N) vector models, we
find strong numerical evidence that the O(N) vector models saturate the
bootstrap constraints at all values of N. We also compute general lower bounds
on the central charge, giving numerical predictions for the values realized in
the O(N) vector models. We compare our predictions to previous computations in
the 1/N expansion, finding precise agreement at large values of N.


title: WASP-12b and HAT-P-8b are Members of Triple Star Systems

abstract:
  We present high spatial resolution images that demonstrate the hot Jupiters
WASP-12b and HAT-P-8b orbit the primary star of hierarchical triple star
systems. In each case, two distant companions with colors and brightness
consistent with M dwarfs co-orbit the planet host as well as one another. Our
adaptive optics images spatially resolve the secondary around WASP-12,
previously identified by Bergfors et al. 2011 and Crossfield et al. 2012, into
two distinct sources separated by 84.3+/-0.6 mas (21 +/- 3 AU). We find that
the secondary to HAT-P-8, also identified by Bergfors et al. 2011, is in fact
composed of two stars separated by 65.3+/-0.5 mas (15+/-1 AU). Our follow-up
observations demonstrate physical association through common proper-motion.
HAT-P-8 C has a particularly low mass, which we estimate to be 0.18+/-0.02Msun
using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable
the first dynamical mass determination for hot Jupiter stellar companions.
These previously well-studied planet hosts now represent higher-order
multi-star systems with potentially complex dynamics, underscoring the
importance of diffraction-limited imaging and providing additional context for
understanding the migrant population of transiting hot Jupiters.


title:
Natural Orbitals and Occupation Numbers for Harmonium: Fermions vs.
  Bosons

abstract:
  For a quantum system of N identical, harmonically interacting particles in a
one-dimensional harmonic trap we calculate for the bosonic and fermionic ground
state the corresponding 1-particle reduced density operator $\rho_1$
analytically. In case of bosons $\rho_1$ is a Gibbs state for an effective
harmonic oscillator. Hence the natural orbitals are Hermite functions and their
occupation numbers obey a Boltzmann distribution. Intriguingly, for fermions
with not too large couplings the natural orbitals coincide up to just a very
small error with the bosonic ones. In case of strong coupling this still holds
qualitatively. Moreover, the decay of the decreasingly ordered fermionic
natural occupation numbers is given by the bosonic one, but modified by an
algebraic prefactor. Significant differences to bosons occur only for the
largest occupation numbers. After all the "discontinuity" at the "Fermi level"
decreases with increasing coupling strength but remains well pronounced even
for strong interaction.


title: Lyman-alpha Heating of Inhomogeneous High-redshift Intergalactic Medium

abstract:
  The intergalactic medium (IGM) prior to the epoch of reionization consists
mostly of neutral hydrogen gas. Ly-alpha photons produced by early stars
resonantly scatter off hydrogen atoms, causing energy exchange between the
radiation field and the gas. This interaction results in moderate heating of
the gas due to the recoil of the atoms upon scattering, which is of great
interest for future studies of the pre-reionization IGM in the HI 21 cm line.
We investigate the effect of this Ly-alpha heating in the IGM with linear
density, temperature, and velocity perturbations. Perturbations smaller than
the diffusion length of photons could be damped due to heat conduction by
Ly-alpha photons. The scale at which damping occurs and the strength of this
effect depend on various properties of the gas, the flux of Ly-alpha photons
and the way in which photon frequencies are redistributed upon scattering. To
find the relevant length scale and the extent to which Ly-alpha heating affects
perturbations, we calculate the gas heating rates by numerically solving
linearized Boltzmann equations in which scattering is treated by the
Fokker-Planck approximation. We find that (1) perturbations add a small
correction to the gas heating rate, and (2) the damping of temperature
perturbations occurs at scales with comoving wavenumber k>10^4 Mpc^{-1}, which
are much smaller than the Jeans scale and thus unlikely to substantially affect
the observed 21 cm signal.


title: Vector boson excitations near deconfined quantum critical points

abstract:
  We show that the N\'eel states of two-dimensional antiferromagnets have low
energy vector boson excitations in the vicinity of deconfined quantum critical
points. We compute the universal damping of these excitations arising from
spin-wave emission. Detection of such a vector boson will demonstrate the
existence of emergent topological gauge excitations in a quantum spin system.


title: Searching for Light Dark Matter with the SLAC Millicharge Experiment

abstract:
  New sub-GeV gauge forces ("dark photons") that kinetically mix with the
photon provide a promising scenario for MeV-GeV dark matter, and are the
subject of a program of searches at fixed-target and collider facilities around
the world. In such models, dark photons produced in collisions may decay
invisibly into dark matter states, thereby evading current searches. We
re-examine results of the SLAC mQ electron beam dump experiment designed to
search for millicharged particles, and find that it was strongly sensitive to
any secondary beam of dark matter produced by electron-nucleus collisions in
the target. The constraints are competitive for dark photon masses in the ~1-30
MeV range, covering part of the parameter space that can reconcile the apparent
(g-2)_{\mu} anomaly. Simple adjustments to the original SLAC search for
millicharges may extend sensitivity to cover a sizable portion of the remaining
(g-2)_{\mu} anomaly-motivated region. The mQ sensitivity is therefore
complementary to on-going searches for visible decays of dark photons. Compared
to existing direct detection searches, mQ sensitivity to electron-dark matter
scattering cross sections is more than an order of magnitude better for a
significant range of masses and couplings in simple models.


title: Fermi Bubbles under Dark Matter Scrutiny. Part I: Astrophysical Analysis

abstract:
  The quest for Dark Matter signals in the gamma-ray sky is one of the most
intriguing and exciting challenges in astrophysics. In this paper we perform
the analysis of the energy spectrum of the \textit{Fermi bubbles} at different
latitudes, making use of the gamma-ray data collected by the Fermi Large Area
Telescope. By exploring various setups for the full-sky analysis we achieve
stable results in all the analyzed latitudes. At high latitude,
$|b|=20^{\circ}-50^{\circ}$, the \textit{Fermi bubbles} energy spectrum can be
reproduced by gamma-ray photons generated by inverse Compton scattering
processes, assuming the existence of a population of high-energy electrons. At
low latitude, $|b|=10^{\circ}-20^{\circ}$, the presence of a bump at
$E_{\gamma}\sim 1-4$ GeV, reveals the existence of an extra component
compatible with Dark Matter annihilation. Our best-fit candidate corresponds to
annihilation into $b\bar{b}$ with mass $M_{\rm DM}= 61.8^{+6.9}_{-4.9}$ GeV and
cross section $<\sigma v> = 3.30^{+0.69}_{-0.49}\times 10^{-26}$
cm$^{3}$s$^{-1}$. In addition, using the energy spectrum of the \textit{Fermi
bubbles}, we derive new conservative but stringent upper limits on the Dark
Matter annihilation cross section.


title:
Conserved current correlators of conformal field theories in 2+1
  dimensions

abstract:
  We compute current correlators of the CP^{N-1} field theory in 2+1
dimensions, both at the critical point and in the phase with spontaneously
broken SU(N) symmetry. Universal constants are obtained to next-to-leading
order in the 1/N expansion. Implications are noted for quantum critical points
of antiferromagnets, and their vicinity.


title: Convex recovery from interferometric measurements

abstract:
  This note formulates a deterministic recovery result for vectors $x$ from
quadratic measurements of the form $(Ax)_i \overline{(Ax)_j}$ for some
left-invertible $A$. Recovery is exact, or stable in the noisy case, when the
couples $(i,j)$ are chosen as edges of a well-connected graph. One possible way
of obtaining the solution is as a feasible point of a simple semidefinite
program. Furthermore, we show how the proportionality constant in the error
estimate depends on the spectral gap of a data-weighted graph Laplacian. Such
quadratic measurements have found applications in phase retrieval, angular
synchronization, and more recently interferometric waveform inversion.


title:
Effect of sampling on the estimation of drift parameter of continuous
  time AR(1) processes

abstract:
  We study the effect of stochastic sampling on the estimation of the drift
parameter of continuous time AR(1) process. A natural distribution free moment
estimator is considered for the drift based on stochastically observed time
points. The effect of the constraint of the minimum separation between
successive samples on the estimation of the drift is studied.


title: The universal Racah-Wigner symbol for Uq(osp(1|2))

abstract:
  We propose a new and elegant formula for the Racah-Wigner symbol of self-dual
continuous series of representations of Uq(osp(1|2)). It describes the entire
fusing matrix for both NS and R sector of N=1 supersymmetric Liouville field
theory. In the NS sector, our formula is related to an expression derived in
[1]. Through analytic continuation in the spin variables, our universal
expression reproduces known formulas for the Racah-Wigner coefficients of
finite dimensional representations.


title: An application of group expansion to the Anderson-Bernoulli model

abstract:
  We establish smoothness of the density of states for 1D lattice Schrodinger
operators with potential taking values $\pm\lambda$, for $\lambda$ in a class
of small algebraic numbers and energy $E\in)-2, 2($ suitably restricted away
from $\pm2$.


title:
Survival of interstellar molecules to prestellar dense core collapse and
  early phases of disk formation

abstract:
  An outstanding question of astrobiology is the link between the chemical
composition of planets, comets, and other solar system bodies and the molecules
formed in the interstellar medium. Understanding the chemical and physical
evolution of the matter leading to the formation of protoplanetary disks is an
important step for this. We provide some new clues to this long-standing
problem using three-dimensional chemical simulations of the early phases of
disk formation: we interfaced the full gas-grain chemical model Nautilus with
the radiation-magnetohydrodynamic model RAMSES, for different configurations
and intensities of magnetic field. Our results show that the chemical content
(gas and ices) is globally conserved during the collapsing process, from the
parent molecular cloud to the young disk surrounding the first Larson core. A
qualitative comparison with cometary composition suggests that comets are
constituted of different phases, some molecules being direct tracers of
interstellar chemistry, while others, including complex molecules, seem to have
been formed in disks, where higher densities and temperatures allow for an
active grain surface chemistry. The latter phase, and its connection with the
formation of the first Larson core, remains to be modeled.


title:
A Herschel Study of D/H in Water in the Jupiter-Family Comet
  45P/Honda-Mrkos-Pajdusakova and Prospects for D/H Measurements with CCAT

abstract:
  We present Herschel observations of water isotopologues in the atmosphere of
the Jupiter-family comet 45P/Honda-Mrkos-Pajdusakova. No HDO emission is
detected, with a 3 sigma upper limit of 2.0 10-4 for the D/H ratio. This value
is consistent with the earlier Herschel measurement in the Jupiter-family comet
103P/Hartley 2. The canonical value of 3 10-4 measured pre-Herschel in a sample
of Oort-cloud comets can be excluded at a 4.5 sigma level. The observations
presented here further confirm that a diversity of D/H ratios exists in the
comet population and emphasize the need for additional measurements with future
ground-based facilities, such as CCAT, in the post-Herschel era.


title:
Measuring ligand-receptor binding kinetics and dynamics using k-space
  image correlation spectroscopy

abstract:
  Accurate measurements of kinetic rate constants for interacting biomolecules
is crucial for understanding the mechanisms underlying intracellular signalling
pathways. The magnitude of binding rates plays a very important molecular
regulatory role which can lead to very different cellular physiological
responses under different conditions. Here, we extend the k-space image
correlation spectroscopy (kICS) technique to study the kinetic binding rates of
systems wherein: (a) fluorescently labelled, free ligands in solution interact
with unlabelled, diffusing receptors in the plasma membrane and (b) systems
where labelled, diffusing receptors are allowed to bind/unbind and interconvert
between two different diffusing states on the plasma membrane. We develop the
necessary mathematical framework for the kICS analysis and demonstrate how to
extract the elevant kinetic binding parameters of the underlying molecular
system from fluorescence video-microscopy image time-series. Finally, by
examining real data for two model experimental systems, we demonstrate how kICS
can be a powerful tool to measure molecular transport coefficients and binding
kinetics.


title: Dephasing in coherent communication with weak signal states

abstract:
  We analyze the ultimate quantum limit on the accessible information for an
optical communication scheme when time bins carry coherent light pulses
prepared in one of several orthogonal modes and the phase undergoes diffusion
after each channel use. This scheme, an example of a quantum memory channel,
can be viewed as noisy pulse position modulation (PPM) keying with phase
fluctuations occurring between consecutive PPM symbols. We derive a general
expression for the output states in the Fock basis and implement a numerical
procedure to calculate the Holevo quantity. Using asymptotic properties of
Toeplitz matrices, we also present an analytic expression for the Holevo
quantity valid for very weak signals and sufficiently strong dephasing when the
dominant contribution comes from the single-photon sector in the Hilbert space
of signal states. Based on numerical results we conjecture an inequality for
contributions to the Holevo quantity from multiphoton sectors which implies
that in the asymptotic limit of weak signals, for arbitrarily small dephasing
the accessible information scales linearly with the average number of photons
contained in the pulse. Such behaviour presents a qualitative departure from
the fully coherent case.


title:
Effective equations for matter-wave gap solitons in higher-order
  transversal states

abstract:
  We demonstrate that an important class of nonlinear stationary solutions of
the three-dimensional (3D) Gross-Pitaevskii equation (GPE) exhibiting
nontrivial transversal configurations can be found and characterized in terms
of an effective one-dimensional (1D) model. Using a variational approach we
derive effective equations of lower dimensionality for BECs in $(m,n_{r})$
transversal states (states featuring a central vortex of charge $m$ as well as
$n_{r}$ concentric zero-density rings at every $z$ plane) which provides us
with a good approximate solution of the original 3D problem. Since the
specifics of the transversal dynamics can be absorbed in the renormalization of
a couple of parameters, the functional form of the equations obtained is
universal. The model proposed finds its principal application in the study of
the existence and classification of 3D gap solitons supported by 1D optical
lattices, where in addition to providing a good estimate for the 3D wave
functions it is able to make very good predictions for the $\mu(N)$ curves
characterizing the different fundamental families. We have corroborated the
validity of our model by comparing its predictions with those from the exact
numerical solution of the full 3D GPE.


title:
Room Temperature In-plane <100> Magnetic Easy Axis for
  Fe3O4/SrTiO3(001):Nb Grown by Infrared PLD

abstract:
  We examine the magnetic easy-axis directions of stoichiometric magnetite
films grown on SrTiO3:Nb by infrared pulsed-laser deposition. Spin-polarized
low-energy electron microscopy reveals that the individual magnetic domains are
magnetized along the in-plane <100> film directions. Magneto-optical Kerr
effect measurements show that the maxima of the remanence and coercivity are
also along in-plane <100> film directions. This easy-axis orientation differs
from bulk magnetite and films prepared by other techniques, establishing that
the magnetic anisotropy can be tuned by film growth.


title:
On the nature of reconnection at a solar coronal null point above a
  separatrix dome

abstract:
  Three-dimensional magnetic null points are ubiquitous in the solar corona,
and in any generic mixed-polarity magnetic field. We consider magnetic
reconnection at an isolated coronal null point, whose fan field lines form a
dome structure. We demonstrate using analytical and computational models
several features of spine-fan reconnection at such a null, including the fact
that substantial magnetic flux transfer from one region of field line
connectivity to another can occur. The flux transfer occurs across the current
sheet that forms around the null point during spine-fan reconnection, and there
is no separator present. Also, flipping of magnetic field lines takes place in
a manner similar to that observed in quasi-separatrix layer or slip-running
reconnection.


title: The enhanced holographic superconductor: is it possible?

abstract:
  It is known that time-dependent perturbations can enhance superconductivity
and increase the critical temperature. If this phenomenon happens to high-T_c
superconductors, one could obtain room-temperature superconductors, but this is
still an open issue experimentally. Meanwhile, we would like to understand this
phenomenon from gravity dual and see if the enhancement is possible for
holographic superconductors. Previous work (arXiv:1104.4098 [hep-th]) has
studied this issue by adding a "time-dependent chemical potential," but their
analysis is questionable as a true dynamic equilibrium. In particular, the AdS
boundary does not supply energy to the bulk spacetime in their setup. A more
appropriate way to discuss the enhancement is to add a time-dependent vector
potential, i.e., a time-dependent electric field. However, the enhancement does
not occur for holographic superconductors.


title:
Spectra of stochastic adding machines based on Cantor Systems of
  numeration

abstract:
  In this paper, we define a stochastic adding machine based on Cantor Systems
of numeration. We also compute the parts of spectra of the transition operator
associated to this stochastic adding machine in different Banach spaces as
$c_0, c$ and $l_{\alpha},\; 1 \leq \alpha \leq +\infty$. These spectra are
connected to fibered Julia sets.


title: Alfvenic propagation: a key to nonlocal effects in magnetized plasmas

abstract:
  A long standing puzzle in fusion research comes from experiments where a
sudden peripheral electron temperature perturbation is accompanied by an almost
simultaneous opposite change in central temperature, in a way incompatible with
local transport models. This paper shows these experiments and similar ones are
fairly well quantitatively reproduced, when induction effects are incorporated
in the total plasma response, alongside standard local diffusive transport, as
suggested in earlier work [V.D. Pustovitov, Plasma Phys. Control. Fusion {\bf
54}, 124036 (2012)].


title: On baryogenesis from dark matter annihilation

abstract:
  We study in detail the conditions to generate the baryon asymmetry of the
universe from the annihilation of dark matter. This scenario requires a low
energy mechanism for thermal baryogenesis, hence we first discuss some of these
mechanisms together with the specific constraints due to the connection with
the dark matter sector. Then we show that, contrary to what stated in previous
studies, it is possible to generate the cosmological asymmetry without adding a
light sterile dark sector, both in models with violation and with conservation
of B-L. In addition, one of the models we propose yields some connection to
neutrino masses.


title:
The Impact of Different Physical Processes on the Statistics of
  Lyman-limit and Damped Lyman-alpha Absorbers

abstract:
  We compute the z = 3 neutral hydrogen column density distribution function
f(NHI) for 19 simulations drawn from the OWLS project using a post-processing
correction for self-shielding calculated with full radiative transfer of the
ionising background radiation. We investigate how different physical processes
and parameters affect the abundance of Lyman-limit systems (LLSs) and damped
Lyman-alpha absorbers (DLAs) including: i) metal-line cooling; ii) the
efficiency of feedback from SNe and AGN; iii) the effective equation of state
for the ISM; iv) cosmological parameters; v) the assumed star formation law
and; vi) the timing of hydrogen reionization . We find that the normalisation
and slope, D = d log10 f /d log10 NHI, of f(NHI) in the LLS regime are robust
to changes in these physical processes. Among physically plausible models,
f(NHI) varies by less than 0.2 dex and D varies by less than 0.18 for LLSs.
This is primarily due to the fact that these uncertain physical processes
mostly affect star-forming gas which contributes less than 10% to f(NHI) in the
the LLS column density range. At higher column densities, variations in f(NHI)
become larger (approximately 0.5 dex at NHI = 10^22 cm^-2 and 1.0 dex at NHI =
10^23 cm^-2) and molecular hydrogen formation also becomes important. Many of
these changes can be explained in the context of self-regulated star formation
in which the amount of star forming gas in a galaxy will adjust such that
outflows driven by feedback balance inflows due to accretion. Data and code to
reproduce all figures can be found at the following url:
https://bitbucket.org/galtay/hi-cddf-owls-1


title:
Relativistic calculations of charge transfer probabilities in U92+ -
  U91+(1s) collisions using the basis set of cubic Hermite splines

abstract:
  A new approach for solving the time-dependent two-center Dirac equation is
presented. The method is based on using the finite basis set of cubic Hermite
splines on a two-dimensional lattice. The Dirac equation is treated in rotating
reference frame. The collision of U92+ (as a projectile) and U91+ (as a target)
is considered at energy E_lab=6 MeV/u. The charge transfer probabilities are
calculated for different values of the impact parameter. The obtained results
are compared with the previous calculations [I. I. Tupitsyn et al., Phys. Rev.
A 82, 042701 (2010)], where a method based on atomic-like Dirac-Sturm orbitals
was employed. This work can provide a new tool for investigation of quantum
electrodynamics effects in heavy-ion collisions near the supercritical regime.


title:
Finite primitive permutation groups containing a permutation having at
  most four cycles

abstract:
  We classify the finite primitive groups containing a permutation with at most
four cycles (including fixed points) in its disjoint cycle representation.


title:
A study on the low mass Drell-Yan production at the CERN LHC within the
  dipole formalism

abstract:
  We present results for the low mass Drell-Yan (DY) production in
proton-proton collisions at the LHC in the color dipole formalism. The DY
differential cross sections at 7 TeV as a function of dilepton rapidity,
transverse momentum and invariant mass are discussed. We have imposed
kinematical cuts related to the low mass DY production investigated by ATLAS
and LHCb collaborations.


title:
A gradient descent technique coupled with a dynamic simulation to
  determine the near optimum orientation of floor plan designs

abstract:
  A prototype tool to assist architects during the early design stage of floor
plans has been developed, consisting of an Evolutionary Program for the Space
Allocation Problem (EPSAP), which generates sets of floor plan alternatives
according to the architect's preferences; and a Floor Plan Performance
Optimization Program (FPOP), which optimizes the selected solutions according
to thermal performance criteria. The design variables subject to optimization
are window position and size, overhangs, fins, wall positioning, and building
orientation. A procedure using a transformation operator with gradient descent,
such as behavior, coupled with a dynamic simulation engine was developed for
the thermal evaluation and optimization process. However, the need to evaluate
all possible alternatives regarding designing variables being used during the
optimization process leads to an intensive use of thermal simulation, which
dramatically increases the simulation time, rendering it unpractical. An
alternative approach is a smart optimization approach, which utilizes an
oriented and adaptive search technique to efficiently find the near optimum
solution. This paper presents the search methodology for the building
orientation of floor plan designs, and the corresponding efficiency and
effectiveness indicators. The calculations are based on 100 floor plan designs
generated by EPSAP. All floor plans have the same design program, location, and
weather data, changing only their geometry. Dynamic simulation of buildings was
effectively used together with the optimization procedure in this approach to
significantly improve the designs. The use of the orientation variable has been
included in the algorithm.


title:
A frame energy for immersed tori and applications to regular homotopy
  classes

abstract:
  The paper is devoted to study the Dirichelet energy of moving frames on
2-dimensional tori immersed in the euclidean $3\leq m$-dimensional space. This
functional, called Frame energy, is naturally linked to the Willmore energy of
the immersion and on the conformal structure of the abstract underlying
surface. As first result, a Willmore-conjecture type lower bound is established
: namely for every torus immersed in $\R^m$, $m\geq 3$, and any moving frame on
it, the frame energy is at least $2\pi^2$ and equalty holds if and only if
$m\geq 4$, the immersion is the standard Clifford torus (up to rotations and
dilations), and the frame is the flat one. Smootheness of the critical points
of the frame energy is proved after the discovery of hidden conservation laws
and, as application, the minimization of the Frame energy in regular homotopy
classes of immersed tori in $\R^3$ is performed.


title:
Randomized algorithms for Generalized Hermitian Eigenvalue Problems with
  application to computing Karhunen-Lo\`{e}ve expansion

abstract:
  We describe randomized algorithms for computing the dominant eigenmodes of
the Generalized Hermitian Eigenvalue Problem (GHEP) $Ax=\lambda Bx$, with $A$
Hermitian and $B$ Hermitian and positive definite. The algorithms we describe
only require forming operations $Ax$, $Bx$ and $B^{-1}x$ and avoid forming
square-roots of $B$ (or operations of the form, $B^{1/2}x$ or $B^{-1/2}x$). We
provide a convergence analysis and a posteriori error bounds that build upon
the work
of~\cite{halko2011finding,liberty2007randomized,martinsson2011randomized}
(which have been derived for the case $B=I$). Additionally, we derive some new
results that provide insight into the accuracy of the eigenvalue calculations.
The error analysis shows that the randomized algorithm is most accurate when
the generalized singular values of $B^{-1}A$ decay rapidly. A randomized
algorithm for the Generalized Singular Value Decomposition (GSVD) is also
provided. Finally, we demonstrate the performance of our algorithm on computing
the Karhunen-Lo\`{e}ve expansion, which is a computationally intensive GHEP
problem with rapidly decaying eigenvalues.


title:
Localisations of cobordism categories and invertible TFTs in dimension
  two

abstract:
  Cobordism categories have played an important role in classical geometry and
more recently in mathematical treatments of quantum field theory. Here we will
compute localisations of two-dimensional discrete cobordism categories. This
allows us, up to equivalence, to determine the category of invertible
two-dimensional topological field theories in the sense of Atiyah. We are able
to treat the orientable, non-orientable, closed and open cases.


title: Sequential Transfer in Multi-armed Bandit with Finite Set of Models

abstract:
  Learning from prior tasks and transferring that experience to improve future
performance is critical for building lifelong learning agents. Although results
in supervised and reinforcement learning show that transfer may significantly
improve the learning performance, most of the literature on transfer is focused
on batch learning tasks. In this paper we study the problem of
\textit{sequential transfer in online learning}, notably in the multi-armed
bandit framework, where the objective is to minimize the cumulative regret over
a sequence of tasks by incrementally transferring knowledge from prior tasks.
We introduce a novel bandit algorithm based on a method-of-moments approach for
the estimation of the possible tasks and derive regret bounds for it.


title:
Casimir interaction at liquid nitrogen temperature: Comparison between
  experiment and theory

abstract:
  We have measured the normalized gradient of the Casimir force between
Au-coated surfaces of the sphere and the plate and equivalent Casimir pressure
between two parallel Au plates at T=77K. These measurements have been performed
by means of dynamic force microscope adapted for operating at low temperatures
in the frequency shift technique. It was shown that the measurement results at
T=77K are in a very good agreement with those at T=300K and with computations
at T=77K using both theoretical approaches to the thermal Casimir force
proposed in the literature. No thermal effect in the Casimir pressure was
observed in the limit of experimental errors with the increase of temperature
from T=77K to T=300K. Taking this into account, we have discussed the possible
role of patch potentials in the comparison between measured and calculated
Casimir pressures.


title: Contextualizing the global relevance of local land change observations

abstract:
  To understand global changes in the Earth system, scientists must generalize
globally from observations made locally and regionally. In land change science
(LCS), local field-based observations are costly and time consuming, and
generally obtained by researchers working at disparate local and regional
case-study sites chosen for different reasons. As a result, global synthesis
efforts in LCS tend to be based on non-statistical inferences subject to
geographic biases stemming from data limitations and fragmentation. Thus, a
fundamental challenge is the production of generalized knowledge that links
evidence of the causes and consequences of local land change to global patterns
and vice versa. The GLOBE system was designed to meet this challenge. GLOBE
aims to transform global change science by enabling new scientific workflows
based on statistically robust, globally relevant integration of local and
regional observations using an online social-computational and geovisualization
system. Consistent with the goals of Digital Earth, GLOBE has the capability to
assess the global relevance of local case-study findings within the context of
over 50 global biophysical, land-use, climate, and socio-economic datasets. We
demonstrate the implementation of one such assessment - a representativeness
analysis - with a recently published meta-study of changes in swidden
agriculture in tropical forests. The analysis provides a standardized indicator
to judge the global representativeness of the trends reported in the
meta-study, and a geovisualization is presented that highlights areas for which
sampling efforts can be reduced and those in need of further study. GLOBE will
enable researchers and institutions to rapidly share, compare, and synthesize
local and regional studies within the global context, as well as contributing
to the larger goal of creating a Digital Earth.


title:
Investigating individual arsenic dopant atoms in silicon using
  low-temperature scanning tunnelling microscopy

abstract:
  We study sub-surface arsenic dopants in a hydrogen terminated Si(001) sample
at 77 K, using scanning tunnelling microscopy and spectroscopy. We observe a
number of different dopant related features that fall into two classes, which
we call As1 and As2. When imaged in occupied states the As1 features appear as
anisotropic protrusions superimposed on the silicon surface topography, and
have maximum intensities lying along particular crystallographic orientations.
In empty-state images the features all exhibit long-range circular protrusions.
The images are consistent with buried dopants that are in the electrically
neutral (D0) charge state when imaged in filled states, but become positively
charged (D+) through electrostatic ionisation when imaged under empty state
conditions, similar to previous observations of acceptors in GaAs. Density
functional theory (DFT) calculations predict that As dopants in the third layer
of the sample induce two states lying just below the conduction band edge,
which hybridize with the surface structure creating features with the surface
symmetry consistent with our STM images. The As2 features have the surprising
characteristic of appearing as a protrusion in filled state images and an
isotropic depression in empty state images, suggesting they are negatively
charged at all biases. We discuss the possible origins of this feature.


title: The Renormalization Group for Disordered Systems

abstract:
  In this thesis we investigate the Renormalization Group (RG) approach in
finite-dimensional glassy systems, whose critical features are still not
well-established, or simply unknown. We focus on spin and structural-glass
models built on hierarchical lattices, which are the simplest non-mean-field
systems where the RG framework emerges in a natural way. The resulting critical
properties shed light on the critical behavior of spin and structural glasses
beyond mean field, and suggest future directions for understanding the
criticality of more realistic glassy systems.


title: Unipotent representations of Lie incidence geometries

abstract:
  If a geometry $\Gamma$ is isomorphic to the residue of a point $A$ of a
shadow geometry of a spherical building $\Delta$, a representation
$\varepsilon_\Delta^A$ of $\Gamma$ can be given in the unipotent radical
$U_{A^*}$ of the stabilizer in $\mathrm{Aut}(\Delta)$ of a flag $A^*$ of
$\Delta$ opposite to $A$, every element of $\Gamma$ being mapped onto a
suitable subgroup of $U_{A^*}$. We call such a representation a unipotent
representation. We develope some theory for unipotent representations and we
examine a number of interesting cases, where a projective embedding of a Lie
incidence geometry $\Gamma$ can be obtained as a quotient of a suitable
unipotent representation $\varepsilon_\Delta^A$ by factorizing over the derived
subgroup of $U_{A^*}$, while $\varepsilon^A_\Delta$ itself is not a proper
quotient of any other representation of $\Gamma$.


title: Dani's Work on Dynamical Systems on Homogeneous Spaces

abstract:
  In honor of S.G.Dani's 65th birthday, we describe some of his many
contributions to the theory and applications of dynamical systems on
homogeneous spaces, with emphasis on unipotent flows.


title:
The operad of temporal wiring diagrams: formalizing a graphical language
  for discrete-time processes

abstract:
  We investigate the hierarchical structure of processes using the mathematical
theory of operads. Information or material enters a given process as a stream
of inputs, and the process converts it to a stream of outputs. Output streams
can then be supplied to other processes in an organized manner, and the
resulting system of interconnected processes can itself be considered a macro
process. To model the inherent structure in this kind of system, we define an
operad $\mathcal{W}$ of black boxes and directed wiring diagrams, and we define
a $\mathcal{W}$-algebra $\mathcal{P}$ of processes (which we call propagators,
after Radul and Sussman). Previous operadic models of wiring diagrams use
undirected wires without length, useful for modeling static systems of
constraints, whereas we use directed wires with length, useful for modeling
dynamic flows of information. We give multiple examples throughout to ground
the ideas.


title: On the Schr\"odinger equation with singular potentials

abstract:
  We study the Cauchy problem for the non-linear Schr\"odinger equation with
singular potentials. For point-mass potential and nonperiodic case, we prove
existence and asymptotic stability of global solutions in weak-L^{p} spaces.
Specific interest is give to the point-like $\delta$ and $\delta'$ impurity and
for two $\delta$-interactions in one dimension. We also consider the periodic
case which is analyzed in a functional space based on Fourier transform and
local-in-time well-posedness is proved.


title: Rigidification of Homotopy Algebras over Finite Product Sketches

abstract:
  Multi-sorted algebraic theories provide a formalism for describing various
structures on spaces that are of interest in homotopy theory. The results of
Badzioch and Bergner showed that an interesting feature of this formalism is
the following rigidification property. Every multi-sorted algebraic theory
defines a category of homotopy algebras, i.e. a category of spaces equipped
with certain structure that is to some extent homotopy invariant. Each such
homotopy algebra can be replaced by a weakly equivalent strict algebra which is
a purely algebraic structure on a space. The equivalence between the homotopy
categories of loop spaces and topological groups is a special instance of this
result.
  In this paper we will introduce the notion of a finite product sketch which
is a useful generalization of a multi-sorted algebraic theory. We will show
that in the setting of finite product sketches we can still obtain results
paralleling these of Badzioch and Bergner, although a rigidification of a
homotopy algebra over a finite product sketch is given by a strict algebra over
an associated multi-sorted algebraic theory.


title:
Searching for TeV emission from GRBs: the status of the H.E.S.S. GRB
  programme

abstract:
  H.E.S.S. is an array of five Imaging Atmospheric Cherenkov Telescopes (IACTs)
located 1800 m above sea level in the Khomas Highland of Namibia and is
sensitive to very-high-energy (VHE) gamma rays between tens of GeV to tens of
TeV. The very-high background rejection capabilities of IACTs provide excellent
sensitivity of H.E.S.S. to GRBs. In this contribution the status of the
H.E.S.S. GRB programme, already started in 2003, is reviewed. A highlight is
the recent addition of the fifth telescope, which is the world's largest IACT.
Its 600 square metre mirror lowers the energy threshold to tens of GeV and
provides an effective area that is ten thousands of times larger than Fermi-LAT
at these energies. The higher performance drive system will reduce the response
time to a GRB alert, which will significantly enhance the chances of a H.E.S.S.
GRB detection. Recent results on selected GRBs will be shown.


title:
Correlations of the upper branch of 1d harmonically trapped
  two-component Fermi gases

abstract:
  We present highly-accurate energy spectra and eigen functions of small 1d
harmonically trapped two-component Fermi gases with interspecies
$\delta$-function interactions, and analyze the correlations of the so-called
upper branch (i.e., the branch that describes a repulsive Fermi gas consisting
of atoms but no molecules) for positive and negative coupling constants.
Changes of the two-body correlations as a function of the interspecies coupling
strength reflect the competition of the interspecies interaction and the
effective repulsion due to the Pauli exclusion principle, and are interpreted
as a few-body analog of a transition from a non-magnetic to a magnetic phase.
Moreover, we show that the eigenstate $\psi_{\rm{adia}}$ of the infinitely
strongly-interacting system with $|n_1+n_2|>2$ and $|n_1-n_2| < n$ ($n_1$ and
$n_2$ denote the number of fermions of components 1 and 2, respectively), which
is reached experimentally by adiabatically changing the system parameters, does
not, as previously proposed, coincide with the wave function $\psi_{\rm{G}}$
obtained by applying a generalized Fermi-Fermi mapping function to the eigen
function of the non-interacting single-component Fermi gas.


title:
Universal scaling function for the two-dimensional Ising model in an
  external field: A pragmatic approach

abstract:
  We report an effective functional form for the spin-spin correlation function
of the 2D Ising model as a function of temperature and field. Although the
Ising model has been well studied, no analytical result for the spin-spin
correlation function exists for arbitrary magnetic fields and temperatures. We
show the validity of our form by comparison with simulations using the Wolff
algorithm, and obtain remarkable precision by including analytic corrections to
scaling. Given recent interest in comparing biomembrane heterogeneity to Ising
criticality, our spin-spin correlation function may be used as a predictive
quantitative measure for FRET or NMR membrane experiments.

categories: cond-mat.stat-mech math-ph math.MP physics.bio-ph


title:
Contributions of the W-boson propagator to muon and tau leptonic decay
  rates

abstract:
  We derive closed expressions and useful expansions for the contributions of
the tree-level W-boson propagator to the the muon and tau leptonic decay rates.
Calling M and m the masses of the initial and final charged leptons, our
results in the limit m=0 are valid to all orders in M^2/M_W^2. In the terms of
O(m_j^2/M_W^2) (m_j=M,m), our leading corrections, of O(M^2/M_W^2), agree with
the canonical value (3/5) M^2/M_W^2, while the coefficient of our subleading
contributions, of O(m^2/M_W^2), differs from that reported in the recent
literature. A possible explanation of the discrepancy is presented. The
numerical effect of the O(m_j^2/M_W^2) corrections is briefly discussed. A
general expression, valid for arbitrary values of M_W, M and m in the range
M_W>M>m, is given in the Appendix. The paper also contains a review of the
traditional definition and evaluation of the Fermi constant.


title:
Specification Construction Using Behaviours, Equivalences, and SMT
  Solvers

abstract:
  We propose a method to write and check a specification including quantifiers
using behaviors, i.e., input-output pairs. Our method requires the following
input from the user: (1) answers to a finite number of queries, each of which
presents some behavior to the user, who responds informing whether the behavior
is "correct" or not; and (2) an "equivalence" theory (set of formulae), which
represents the users opinion about which pairs of behaviors are equivalent with
respect to the specification; and (3) a "vocabulary", i.e., a set of formulae
which provide the basic building blocks for the specification to be written.
Alternatively, the user can specify a type theory and a simple relational
grammar, and our method can generate the vocabulary and equivalence theories.
Our method automatically generates behaviors using a satisfiability modulo
theory solver. Since writing a specification consists of formalizing ideas that
are initially informal, there must, by definition, be at least one "initial"
step where an informal notion is formalized by the user in an ad hoc manner.
This step is the provision of the equivalence theory and vocabulary; we call it
the primitive formalization step. We contend that it is considerably easier to
write an equivalence theory and vocabulary than to write a full-blown formal
specification from scratch, and we provide experimental evidence for this
claim. We also show how vocabularies can be constructed hierarchically, with a
specification at one level providing vocabulary material for the next level.


title: Alpha-clustered hypernuclei and chiral SU(3) dynamics

abstract:
  Light hypernuclei with an $\alpha$ cluster substructure of the core nucleus
are studied using an accurate cluster approach (the Hyper-THSR wave function)
in combination with a density-dependent $\Lambda$ hyperon-nuclear interaction
derived from chiral SU(3) effective field theory. This interaction includes
important two-pion exchange processes involving $\Sigma N$ intermediate states
and associated three-body mechanisms as well as effective mass and surface
terms arising in a derivative expansion of the in-medium $\Lambda$ self-energy.
Applications and calculated results are presented and discussed for
$_\Lambda^9$Be and $^{13}_\Lambda$C. Furthermore, the result of the lightest
$\alpha$ clustered hypernucleus, $^5_{\Lambda}$He using realistic $ab initio$
four nucleon density is shown.


title:
Proceedings Combined 20th International Workshop on Expressiveness in
  Concurrency and 10th Workshop on Structural Operational Semantics

abstract:
  This volume contains the proceedings of the Combined 20th International
Workshop on Expressiveness in Concurrency and the 10th Workshop on Structural
Operational Semantics (EXPRESS/SOS 2013) which was held on 26th August, 2013 in
Buenos Aires, Argentina, as an affiliated workshop of CONCUR 2013, the 24th
International Conference on Concurrency Theory.
  The EXPRESS workshops aim at bringing together researchers interested in the
expressiveness of various formal systems and semantic notions, particularly in
the field of concurrency. Their focus has traditionally been on the comparison
between programming concepts (such as concurrent, functional, imperative, logic
and object-oriented programming) and between mathematical models of computation
(such as process algebras, Petri nets, event structures, modal logics, and
rewrite systems) on the basis of their relative expressive power. The EXPRESS
workshop series has run successfully since 1994 and over the years this focus
has become broadly construed.
  The SOS workshops aim at being a forum for researchers, students and
practitioners interested in new developments, and directions for future
investigation, in the field of structural operational semantics. One of the
specific goals of the SOS workshop series is to establish synergies between the
concurrency and programming language communities working on the theory and
practice of SOS. Reports on applications of SOS to other fields are also most
welcome, including: modelling and analysis of biological systems, security of
computer systems programming, modelling and analysis of embedded systems,
specification of middle-ware and coordination languages, programming language
semantics and implementation, static analysis software and hardware
verification, and semantics for domain-specific languages and model-based
engineering.


title:
The G305 star-forming complex: radio continuum and molecular line
  observations

abstract:
  We present 109-115 GHz (3 mm) wide-field spectral line observations of 12^CO,
13^CO and C^18O J=1-0 molecular emission and 5.5 and 8.8 GHz (6 and 3 cm) radio
continuum emission towards the high-mass star forming complex known as G305.
The morphology of G305 is dominated by a large evacuated cavity at the centre
of the complex driven by clusters of O stars surrounded by molecular gas. Our
goals are to determine the physical properties of the molecular environment and
reveal the relationship between the molecular and ionised gas and star
formation in G305. This is in an effort to characterise the star-forming
environment and constrain the star formation history in an attempt to evaluate
the impact of high-mass stars on the evolution of the G305 complex.
  Analysis of CO emission in G305 reveals 156 molecular clumps with the
following physical characteristics. The 5.5 and 8.8GHz radio continuum emission
reveals an extended low surface brightness ionised environment within which we
identify 15 large-scale features with a further eight smaller sources projected
within these features. By comparing to mid infrared emission and archival data,
we identify nine HII regions, seven compact HII regions, one UC HII region,
four extended regions. The total integrated flux of the radio continuum
emission at 5.5 GHz is ~180 Jy corresponding to a Lyman continuum output of
2.4x10^50 photons s^-1. We compare the ionised and molecular environment with
optically identified high-mass stars and ongoing star formation, identified
from the literature. Analysis of this dataset reveals a star formation rate of
0.008--0.016 and efficiency of 7--12%, allows us to probe the star formation
history of the region and discuss the impact of high-mass stars on the
evolution of G305.


title:
Matrix elements of one-body and two-body operators between arbitrary HFB
  multi-quasiparticle states

abstract:
  We present new formulae for the matrix elements of one-body and two-body
physical operators in compact forms, which are applicable to arbitrary
Hartree-Fock-Bogoliubov wave functions, including those for multi-quasiparticle
excitations. The test calculations show that our formulae may substantially
accelerate the process of symmetry restoration when applied to the heavy
nuclear system.


title:
A Simulation of the Optical Attenuation of TPB Coated Light-guide
  Detectors

abstract:
  This note describes simple simulations which were performed in order to
understand the attenuation behaviors of acrylic light-guides operated in air
and argon, which were characterized in \cite{Baptista:2012bf}. Whilst these
simulations are only at the level of sophistication of a toy model, they
illustrate interesting non-exponential light attenuation effects and the
differences between operating light-guide based detectors in argon and air
environments. We investigate the effects of surface absorption, surface
roughness and wavelength dependence, and use a model tuned on the light-guide
attenuation curve measured in air to make a prediction of the light-guide
attenuation curve in argon. This curve is compared with data from a liquid
argon test stand, and an improvement over a simple exponential model is
observed.


title:
On the redshift of the gamma-ray blazar PKS 0447-439: Optical
  spectroscopy using Gemini observations with high S/N ratio

abstract:
  The BL-Lac blazar PKS 0447-439 was detected at very high energy gamma-rays by
HESS following the discovery by Fermi-LAT. The lack of both emission and
absorption lines in BL-Lacs make the estimation of their redshifts very
difficult. Modeling the drop in gamma-ray spectra it was possible to have an
estimation of redshift for PKS 0447-439 of z approx 0.2, which is compatible
with the value z=0.205 reported by the identification of Ca II absorption lines
in optical spectra. By the identification of a weak line of Mg II using spectra
with average signal-to-noise S/N approx 80, it has been recently reported a
lower limit for the redshift of this blazar of z<=1.246. Triggered by this
controversy, we have proposed new optical observations with the Gemini South
telescope to perform further spectroscopic analysis with very high S/N ratio
(approx 200-500). In this work we present a new optical spectrum of PKS
0447-439, and report on the analysis and results of such observations. Even
with this significantly high quality signal we were not able to identify any
spectral features to allow an estimation of the redshift. In agreement with
other recent studies, we identify the Mg II line reported previously as
originated in the Earth's atmosphere, and conclude the lower limit of the
redshift is incorrect. More interestingly, we could not identify the Ca II
absorption lines used to report a redshift of 0.205.


title: Reconstructing top quarks at the upgraded LHC and at future accelerators

abstract:
  This report describes the studies performed for the Snowmass "Top algorithms
and detectors" High Energy Frontier Study Group.


title: Narrow linewidth Brillouin laser based on chalcogenide photonic chip

abstract:
  We present the first demonstration of a narrow linewidth, waveguide-based
Brillouin laser which is enabled by large Brillouin gain of a chalcogenide
chip. The waveguides are equipped with vertical tapers for low loss coupling.
Due to optical feedback for the Stokes wave, the lasing threshold is reduced to
360 mW, which is 5 times lower than the calculated single-pass Brillouin
threshold for the same waveguide. The slope efficiency of the laser is found to
be 30% and the linewidth of 100 kHz is measured using a self-heterodyne method.


title:
Formation, orbital and thermal evolution, and survival of planetary-mass
  clumps in the early phase of circumstellar disk evolution

abstract:
  We report the results of our three-dimensional radiation hydrodynamics
simulation of collapsing unmagnetized molecular cloud cores. We investigate the
formation and evolution of the circumstellar disk and the clumps formed by disk
fragmentation. Our simulation shows that disk fragmentation occurs in the early
phase of circumstellar disk evolution and many clumps form. The clump can be
represented by a polytrope sphere of index $n \sim 3$ and $n \gtrsim 4$ at
central temperature $T_c \lesssim100$ K and $T_c \gtrsim 100$ K, respectively.
We demonstrate, numerically and theoretically, that the maximum mass of the
clump, beyond which it inevitably collapses, is $\sim 0.03 M_{\odot}$. The
entropy of the clump increases during its evolution, implying that evolution is
chiefly determined by mass accretion from the disk rather than by radiative
cooling. Although most of the clumps rapidly migrate inward and finally fall
onto the protostar, a few clumps remain in the disk. The central density and
temperature of the surviving clump rapidly increase and the clump undergoes a
second collapse within 1000 - 2000 years after its formation. In our
simulation, three second cores of masses $0.2\msun$, $0.15\msun$, and
$0.06\msun$ formed. These are protostars or brown dwarfs rather than
protoplanets. For the clumps to survive as planetary-mass objects, the rapid
mass accretion should be prevented by some mechanisms.


title:
Relativistic Jet Properties of GeV-TeV Blazars and Possible Implications
  for the Jet Formation, Composition, and Cavity Kinematics

abstract:
  We fit the spectral energy distributions (SEDs) of a GeV-TeV FSRQ sample with
the leptonic model. Their gamma_min of the relativistic electron distributions,
which significantly affect the estimates of the jet properties, are
constrained, with a typical value of 48. Their jet power, magnetized parameter,
radiation efficiency, and jet production/radiation rates per central black hole
(BH) mass are derived and compared to that of BL Lacs. We show that he FSRQ
jets may be dominated by the Poynting flux and have a high radiation
efficiency, whereas the BL Lac jets are likely dominated by particles and have
a lower radiation efficiency than FSRQs. Being different from BL Lacs, the jet
powers of FSRQs are proportional to their central BH masses. The jet production
and radiation rates of the FSRQs distribute in narrow ranges and are correlated
with each other, whereas no similar feature is found for the BL Lacs. We also
show that the jet power is correlated with the cavity kinetic power, and the
magnetic field energy in the jets may provide the cavity kinetic energy of
FSRQs and the kinetic energy of cold protons in the jets may be crucial for
cavity kinetic energy of BL Lacs. We suggest that the dominating formation
mechanism of FSRQ jets may be the BZ process, but BL Lac jets may be produced
via the BP and/or BZ processes, depending on the structures and accretion rates
of accretion disks.


title: Zitterbewegung in Bogoliubov's System

abstract:
  We show that Bogoliubov's quasiparticle in superfluid $^3He-B$ undergoes the
Zitterbewegung, as a free relativistic Dirac's electron does. The expectation
value of position, as well as spin, of the quasiparticle is obtained and
compared with that of the Dirac's electron. In particular, the Zitterbewegung
of Bogoliubov's quasiparticle has a frequency approximately $10^5$ lower than
that of an electron, rendering a more promising experimental observation.


title: Coupling Electromagnetism to Global Charge

abstract:
  It is shown that an alternative to the standard scalar QED is possible. In
this new version there is only global gauge invariance as far as the charged
scalar fields are concerned although local gauge invariance is kept for the
electromagnetic field. The electromagnetic coupling has the form
  $j_\mu (A^{\mu} +\partial^{\mu}B)$ where $B$ is an auxiliary field and the
current $j_\mu$ is $A_{\mu}$ independent so that no "sea gull terms" are
introduced. In a model of this kind spontaneous breaking of symmetry does not
lead to photon mass generation, instead the Goldstone boson becomes a massless
source for the electromagnetic field. Infrared questions concerning the theory
when spontaneous symmetry breaking takes place and generalizations to global
vector QED are discussed. In this framework Q-Balls and other non topological
solitons that owe their existence to a global U(1) symmetry can be coupled to
electromagnetism and could represent multiply charged particles now in search
in the LHC. Furthermore, we give an example where an "Emergent" Global Scalar
QED can appear from an axion photon system in an external magnetic field.
Finally, formulations of Global scalar QED that allow perturbative expansions
without sea gulls are developed.


title: Edge effects in game theoretic dynamics of spatially structured tumours

abstract:
  Background: Analysing tumour architecture for metastatic potential usually
focuses on phenotypic differences due to cellular morphology or specific
genetic mutations, but often ignore the cell's position within the
heterogeneous substructure. Similar disregard for local neighborhood structure
is common in mathematical models.
  Methods: We view the dynamics of disease progression as an evolutionary game
between cellular phenotypes. A typical assumption in this modeling paradigm is
that the probability of a given phenotypic strategy interacting with another
depends exclusively on the abundance of those strategies without regard local
heterogeneities. We address this limitation by using the Ohtsuki-Nowak
transform to introduce spatial structure to the go vs. grow game.
  Results: We show that spatial structure can promote the invasive (go)
strategy. By considering the change in neighbourhood size at a static boundary
-- such as a blood-vessel, organ capsule, or basement membrane -- we show an
edge effect that allows a tumour without invasive phenotypes in the bulk to
have a polyclonal boundary with invasive cells. We present an example of this
promotion of invasive (EMT positive) cells in a metastatic colony of prostate
adenocarcinoma in bone marrow.
  Interpretation: Pathologic analyses that do not distinguish between cells in
the bulk and cells at a static edge of a tumour can underestimate the number of
invasive cells. We expect our approach to extend to other evolutionary game
models where interaction neighborhoods change at fixed system boundaries.


title: A note on the singularity category of an endomorphism ring

abstract:
  We propose the notion of partial resolution of a ring, which is by definition
the endomorphism ring of a certain generator of the given ring. We prove that
the singularity category of the partial resolution is a quotient of the
singularity category of the given ring. Consequences and examples are given.


title:
Luhman 16AB: A Remarkable, Variable L/T Transition Binary 2 pc from the
  Sun

abstract:
  Luhman (2013) has reported the discovery of a brown dwarf binary system only
2.01+/-0.15 pc from the Sun. The binary is well-resolved with a projected
separation of 1.5", and spectroscopic observations have identified the
components as late-L and early-T dwarfs. The system exhibits several remarkable
traits, including a "flux reversal", where the T dwarf is brighter over 0.9-1.3
micron but fainter at other wavelengths; and significant (~10%) short-period
(~4.9 hr) photometric variability with a complex light curve. These
observations suggest spatial variations in condensate cloud structure, which is
known to evolve substantially across the L dwarf/T dwarf transition. Here we
report preliminary results from a multi-site monitoring campaign aimed at
probing the spectral and temporal properties of this source. Focusing on our
spectroscopic observations, we report the first detections of NIR spectral
variability, present detailed analysis of K I lines that confirm differences in
condensate opacity between the components; and preliminary determinations of
radial and rotational velocities based on high-resolution NIR spectroscopy.


title:
On convergence of general wavelet decompositions of nonstationary
  stochastic processes

abstract:
  The paper investigates uniform convergence of wavelet expansions of Gaussian
random processes. The convergence is obtained under simple general conditions
on processes and wavelets which can be easily verified. Applications of the
developed technique are shown for several classes of stochastic processes. In
particular, the main theorem is adjusted to the fractional Brownian motion
case. New results on the rate of convergence of the wavelet expansions in the
space $C([0,T])$ are also presented.


title: Status and New Ideas Regarding Liquid Argon Detectors

abstract:
  Large (up to $\sim 100$ kt) liquid argon time-projection chamber detectors
are presently being considered for proton decay searches and neutrino
astrophysics, as well as for far detectors for the next generation of
long-baseline neutrino oscillation experiments that aim to determine neutrino
mass hierarchy and search for CP violation in the leptonic sector. These
detectors rely on the capabilities to assemble large volumes of LAr in
ultrahigh-purity conditions, possibly in an underground environment, and to
achieve relatively long drifts for the ionization charge. Several proposals
have been developed, each of which takes a different approach to the design of
the cryogenic vessels and has different scales of modularity to reach the final
mass dictated by physics. New detector concepts, with innovative designs of
readout electronics and novel methods for the readout of the ionization charge
and scintillation light, have been proposed.


title: Convergence of a Second Order Markov Chain

abstract:
  In this paper, we consider convergence properties of a second order Markov
chain. Similar to a column stochastic matrix is associated to a Markov chain, a
so called {\em transition probability tensor} $P$ of order 3 and dimension $n$
is associated to a second order Markov chain with $n$ states. For this $P$,
define $F_P$ as $F_P(x):=Px^{2}$ on the $n-1$ dimensional standard simplex
$\Delta_n$. If 1 is not an eigenvalue of $\nabla F_P$ on $\Delta_n$ and $P$ is
irreducible, then there exists a unique fixed point of $F_P$ on $\Delta_n$. In
particular, if every entry of $P$ is greater than $\frac{1}{2n}$, then 1 is not
an eigenvalue of $\nabla F_P$ on $\Delta_n$. Under the latter condition, we
further show that the second order power method for finding the unique fixed
point of $F_P$ on $\Delta_n$ is globally linearly convergent and the
corresponding second order Markov process is globally $R$-linearly convergent.


title: Droplets moving on a fluid surface: interference pattern from two slits

abstract:
  The Feynman path integral approach for solving the motion of a droplet along
a silicon oil surface is developed by replacing the Planck constant by a
surrogate parameter. The latter is proportional to the surface tension of the
silicon oil multiplied by the area of the thin air film, separating the droplet
from the oil, and by the half-period of the Faraday oscillations. It is shown
that the Navier-Stokes equation together with the mass conservation equation
can be reduced to the Schr\"{o}dinger equation when the surrogate parameter
replaces the Planck constant. The Feynman path integral underlying the
Schr\"{o}dinger equation is used then to calculate a wave function that plays
the role of the de Broglie pilot-wave.


title: Memcapacitive neural networks

abstract:
  We show that memcapacitive (memory capacitive) systems can be used as
synapses in artificial neural networks. As an example of our approach, we
discuss the architecture of an integrate-and-fire neural network based on
memcapacitive synapses. Moreover, we demonstrate that the
spike-timing-dependent plasticity can be simply realized with some of these
devices. Memcapacitive synapses are a low-energy alternative to memristive
synapses for neuromorphic computation.


title: Superadiabatic dynamics in open quantum systems

abstract:
  We extend the concept of superadiabatic dynamics, or transitionless quantum
driving, to quantum open systems whose evolution is governed by a master
equation in the Lindblad form. We provide the general framework needed to
determine the control strategy required to achieve superadiabaticity. We apply
our formalism to two examples consisting of a two-level system coupled to
environments with time-dependent bath operators.


title:
A Deterministic Construction of Projection matrix for Adaptive
  Trajectory Compression

abstract:
  Compressive Sensing, which offers exact reconstruction of sparse signal from
a small number of measurements, has tremendous potential for trajectory
compression. In order to optimize the compression, trajectory compression
algorithms need to adapt compression ratio subject to the compressibility of
the trajectory. Intuitively, the trajectory of an object moving in starlight
road is more compressible compared to the trajectory of a object moving in
winding roads, therefore, higher compression is achievable in the former case
compared to the later. We propose an in-situ compression technique underpinning
the support vector regression theory, which accurately predicts the
compressibility of a trajectory given the mean speed of the object and then
apply compressive sensing to adapt the compression to the compressibility of
the trajectory. The conventional encoding and decoding process of compressive
sensing uses predefined dictionary and measurement (or projection) matrix
pairs. However, the selection of an optimal pair is nontrivial and exhaustive,
and random selection of a pair does not guarantee the best compression
performance. In this paper, we propose a deterministic and data driven
construction for the projection matrix which is obtained by applying singular
value decomposition to a sparsifying dictionary learned from the dataset. We
analyze case studies of pedestrian and animal trajectory datasets including GPS
trajectory data from 127 subjects. The experimental results suggest that the
proposed adaptive compression algorithm, incorporating the deterministic
construction of projection matrix, offers significantly better compression
performance compared to the state-of-the-art alternatives.