title:
Learning Non-Parametric Basis Independent Models from Point Queries via
  Low-Rank Methods

abstract:
  We consider the problem of learning multi-ridge functions of the form f(x) =
g(Ax) from point evaluations of f. We assume that the function f is defined on
an l_2-ball in R^d, g is twice continuously differentiable almost everywhere,
and A \in R^{k \times d} is a rank k matrix, where k << d. We propose a
randomized, polynomial-complexity sampling scheme for estimating such
functions. Our theoretical developments leverage recent techniques from low
rank matrix recovery, which enables us to derive a polynomial time estimator of
the function f along with uniform approximation guarantees. We prove that our
scheme can also be applied for learning functions of the form: f(x) =
\sum_{i=1}^{k} g_i(a_i^T x), provided f satisfies certain smoothness conditions
in a neighborhood around the origin. We also characterize the noise robustness
of the scheme. Finally, we present numerical examples to illustrate the
theoretical bounds in action.


title: Selective and Ramsey ultrafilters on $G$-spaces

abstract:
  Let $G$ be a group, $X$ be an infinite transitive $G$-space. A free
ultrafilter $\UU$ on $X$ is called $G$-selective if, for any $G$-invariant
partition $\PP$ of $X$, either one cell of $\PP$ is a member of $\UU$, or there
is a member of $\UU$ which meets each cell of $\PP$ in at most one point. We
show (Theorem 1) that in ZFC with no additional set-theoretical assumptions
there exists a $G$-selective ultrafilter on $X$, describe all $G$-spaces $X$
(Theorem 2) such that each free ultrafilter on $X$ is $G$-selective, and prove
(Theorem 3) that a free ultrafilter $\UU$ on $\omega$ is selective if and only
if $\UU$ is $G$-selective with respect to the action of any countable group $G$
of permutations of $\omega$.
  A free ultrafilter $\UU$ on $X$ is called $G$-Ramsey if, for any
$G$-invariant coloring $\chi:[G]^2 \to \{0,1\}$, there is $U\in \UU$ such that
$[U]^2$ is $\chi$-monochrome. By Theorem 4, each $G$-Ramsey ultrafilter on $X$
is $G$-selective. Theorems 5 and 6 give us a plenty of $\mathbb{Z}$-selective
ultrafilters on $\mathbb{Z}$ (as a regular $\mathbb{Z}$-space) but not
$\mathbb{Z}$-Ramsey. We conjecture that each $\mathbb{Z}$-Ramsey ultrafilter is
selective.


title: Asymptotic structures of cardinals

abstract:
  A ballean is a set $X$ endowed with some family $\F$ of its subsets, called
the balls, in such a way that $(X,\F)$ can be considered as an asymptotic
counterpart of a uniform topological space. Given a cardinal $\kappa$, we
define $\F$ using a natural order structure on $\kappa$. We characterize
balleans up to coarse equivalence, give the criterions of metrizability and
cellularity, calculate the basic cardinal invariant of these balleans. We
conclude the paper with discussion of some special ultrafilters on cardinal
balleans.


title:
Delineating geographical regions with networks of human interactions in
  an extensive set of countries

abstract:
  Large-scale networks of human interaction, in particular country-wide
telephone call networks, can be used to redraw geographical maps by applying
algorithms of topological community detection. The geographic projections of
the emerging areas in a few recent studies on single regions have been
suggested to share two distinct properties: first, they are cohesive, and
second, they tend to closely follow socio-economic boundaries and are similar
to existing political regions in size and number. Here we use an extended set
of countries and clustering indices to quantify overlaps, providing ample
additional evidence for these observations using phone data from countries of
various scales across Europe, Asia, and Africa: France, the UK, Italy, Belgium,
Portugal, Saudi Arabia, and Ivory Coast. In our analysis we use the known
approach of partitioning country-wide networks, and an additional iterative
partitioning of each of the first level communities into sub-communities,
revealing that cohesiveness and matching of official regions can also be
observed on a second level if spatial resolution of the data is high enough.
The method has possible policy implications on the definition of the
borderlines and sizes of administrative regions.


title:
Generalized Lazarsfeld-Mukai bundles and a conjecture of Donagi and
  Morrison

abstract:
  Let S be a K3 surface and assume for simplicity that it does not contain any
(-2)-curve. Using coherent systems, we express every non-simple
Lazarsfeld-Mukai bundle on S as an extension of two sheaves of some special
type, that we refer to as generalized Lazarsfeld-Mukai bundles. This has
interesting consequences concerning the Brill-Noether theory of curves C lying
on S. From now on, let g denote the genus of C and A be a complete linear
series of type g^r_d on C such that d<= g-1 and the corresponding Brill-Noether
number is negative. First, we focus on the cases where A computes the Clifford
index; if r>1 and with only some completely classified exceptions, we show that
A coincides with the restriction to C of a line bundle on S. This is a
refinement of Green and Lazarsfeld's result on the constancy of the Clifford
index of curves moving in the same linear system. Then, we study a conjecture
of Donagi and Morrison predicting that, under no hypothesis on its Clifford
index, A is contained in a g^s_e which is cut out from a line bundle on S and
satisfies e<= g-1. We provide counterexamples to the last inequality already
for r=2. A slight modification of the conjecture, which holds for r=1,2, is
proved under some hypotheses on the pair (C,A) and its deformations. We show
that the result is optimal (in the sense that our hypotheses cannot be avoided)
by exhibiting, in the Appendix, some counterexamples obtained jointly with
Andreas Leopold Knutsen.


title: Emergent General Relativity from Fisher Information Metric

abstract:
  We derive the Einstein tensor from the Fisher information metric that is
defined by the probability distribution of a statistical mechanical system. We
find that the tensor naturally contains essential information of the
energy-momentum tensor of a classical scalar field, when the entropy data or
the spectrum data of the system are embedded into the classical field as the
field strength. Thus, we can regard the Einstein equation as the equation of
coarse-grained states for the original microscopic system behind the classical
field theory. We make some remarks on quantization of gravity and various
quantum-classical correspondences.


title:
An energy- and charge-conserving, nonlinearly implicit, electromagnetic
  1D-3V Vlasov-Darwin particle-in-cell algorithm

abstract:
  A recent proof-of-principle study proposes a nonlinear electrostatic implicit
particle-in-cell (PIC) algorithm in one dimension (Chen, Chacon, Barnes, J.
Comput. Phys. 230 (2011) 7018). The algorithm employs a kinetically enslaved
Jacobian-free Newton-Krylov (JFNK) method, and conserves energy and charge to
numerical round-off. In this study, we generalize the method to electromagnetic
simulations in 1D using the Darwin approximation of Maxwell's equations, which
avoids radiative aliasing noise issues by ordering out the light wave. An
implicit, orbit-averaged time-space-centered finite difference scheme is
applied to both the 1D Darwin field equations (in potential form) and the 1D-3V
particle orbit equations to produce a discrete system that remains exactly
charge- and energy-conserving. Furthermore, enabled by the implicit Darwin
equations, exact conservation of the canonical momentum per particle in any
ignorable direction is enforced via a suitable scattering rule for the magnetic
field. Several 1D numerical experiments demonstrate the accuracy and the
conservation properties of the algorithm.


title: Mobility Diversity in Mobile Wireless Networks

abstract:
  We introduce the novel concept of mobility diversity for mobile sensor or
communication networks as the diversity introduced by transmitting data over
different topologies of the network. We show how node mobility can provide
diversity by changing the topology of the network. More specifically, we
consider a mobile network of a sensor node and a number of sink nodes which are
all moving randomly according to different Wiener process mobility models.
Assuming that the network topology evolves with time and assuming that the
connectivity of the sensor node to at least one sink node is needed for
successful communication, we calculate three performance measures for this
network, i) the expected number of time instants, where the sensor node is
connected to at least one sink node, ii) the probability of outage, being the
probability that no sink node is in the vicinity of the sensor node during the
observation interval, and finally, iii) the maximum number of consequent
failures in the communication. Our theoretical and numerical analysis show that
increasing the mobility parameter of the sensor node increases the average
number of successful transmissions, decreases the probability of outage, and
reduces the maximum delay in the senor-sink communication.


title: Normal-stress coefficients and rod climbing in colloidal dispersions

abstract:
  We calculate tractable microscopic expressions for the low-shear
normal-stress coefficients of colloidal dispersions. Although restricted to the
low rate regime, the presented formulas are valid for all volume fractions
below the glass transition and for any interaction potential. Numerical results
are presented for a system of colloids interacting via a hard-core attractive
Yukawa potential, for which we explore the interplay between attraction
strength and volume fraction. We show that the normal-stress coefficients
exhibit nontrivial features close to the critical point and at high volume
fractions in the vicinity of the reentrant glass transition. Finally, we
exploit our formulas to make predictions about rod-climbing effects in
attractive colloidal dispersions.


title: Elastic swimmer on a free surface

abstract:
  We present in this fluid dynamics video a novel experimental setup with
self-propelled swimmers on a free surface. The swimmers, modeled as flexible
thin filaments, are subjected to external electromagnetic forcing driving a
propagating elastic wave that gives rise to self- propulsion. The
fluid-structure interaction problem of these passive anguilliform swimmers is
analyzed in:
  S. Ramananarivo, R. Godoy-Diana, and B. Thiria. Passive elastic mechanism to
mimic fish-muscles action in anguilliform swimming. J. R. Soc. Interface, 10,
20130667 (2013). DOI:10.1098/rsif.2013.0667


title: Black Holes, Supernovae and Gamma Ray Bursts

abstract:
  We review recent progress in our understanding of the nature of gamma ray
bursts (GRBs) and in particular, of the relationship between short GRBs and
long GRBs. The first example of a short GRB is described. The coincidental
occurrence of a GRB with a supernova (SN) is explained within the induced
gravitational collapse (IGC) paradigm, following the sequence: 1) an initial
binary system consists of a compact carbon-oxygen (CO) core star and a neutron
star (NS); 2) the CO core explodes as a SN, and part of the SN ejecta accretes
onto the NS which reaches its critical mass and collapses to a black hole (BH)
giving rise to a GRB; 3) a new NS is generated by the SN as a remnant. The
observational consequences of this scenario are outlined.


title:
Spectroscopy of Optically Selected BL Lac Objects and their gamma-ray
  emission

abstract:
  We present Very Large Telescope optical spectroscopy of nine BL Lac objects
of unknown redshift belonging to the list of optically selected radio loud BL
Lacs candidates. We explore their spectroscopic properties and the possible
link with gamma ray emission. From the new observations we determine the
redshift of four objects from faint emission lines or from absorption features
of the host galaxy. In three cases we find narrow intervening absorptions from
which a lower limit to the redshift is inferred. For the remaining two
featureless sources, lower limits to the redshift are deduced from the very
absence of spectral lines. A search for gamma counterpart emission shows that
six out of nine are Fermi gamma-ray emitters with two new detections. Our
analysis suggests that most of the BL Lac still lacking of redshift information
are most probably located at high redshift.


title: Null-homologous exotic surfaces in 4-manifolds

abstract:
  In this paper we exhibit infinite families of embedded tori in 4-manifolds
that are topologically isotopic but smoothly distinct. The interesting thing
about these tori is that they are topologically trivial in the sense that each
bounds a topologically embedded solid handlebody. This implies that there are
stably ribbon surfaces in 4-manifolds that are not ribbon.


title: Action and entanglement in gravity and field theory

abstract:
  In non-gravitational quantum field theory, the entanglement entropy across a
surface depends on the short-distance regularization. Quantum gravity should
not require such regularization, and it's been conjectured that the
entanglement entropy there is always given by the black hole entropy formula
evaluated on the entangling surface. We show that these statements have precise
classical counterparts at the level of the action. Specifically, we point out
that the action can have a non-additive imaginary part. In gravity, the latter
is fixed by the black hole entropy formula, while in non-gravitating theories,
it is arbitrary. From these classical facts, the entanglement entropy
conjecture follows by heuristically applying the relation between actions and
wavefunctions.


title: Parallel coordinate descent for the Adaboost problem

abstract:
  We design a randomised parallel version of Adaboost based on previous studies
on parallel coordinate descent. The algorithm uses the fact that the logarithm
of the exponential loss is a function with coordinate-wise Lipschitz continuous
gradient, in order to define the step lengths. We provide the proof of
convergence for this randomised Adaboost algorithm and a theoretical
parallelisation speedup factor. We finally provide numerical examples on
learning problems of various sizes that show that the algorithm is competitive
with concurrent approaches, especially for large scale problems.


title: Symmetric Groups and Quotient Complexity of Boolean Operations

abstract:
  The quotient complexity of a regular language L is the number of left
quotients of L, which is the same as the state complexity of L. Suppose that L
and L' are binary regular languages with quotient complexities m and n, and
that the transition semigroups of the minimal deterministic automata accepting
L and L' are the symmetric groups S_m and S_n of degrees m and n, respectively.
Denote by o any binary boolean operation that is not a constant and not a
function of one argument only. For m,n >= 2 with (m,n) not in
{(2,2),(3,4),(4,3),(4,4)} we prove that the quotient complexity of LoL' is mn
if and only either (a) m is not equal to n or (b) m=n and the bases (ordered
pairs of generators) of S_m and S_n are not conjugate. For (m,n)\in
{(2,2),(3,4),(4,3),(4,4)} we give examples to show that this need not hold. In
proving these results we generalize the notion of uniform minimality to direct
products of automata. We also establish a non-trivial connection between
complexity of boolean operations and group theory.


title: A note on knot surgery

abstract:
  In this paper we clarify an issue in the knot surgery construction of
Fintushel and Stern. Using knot surgery, they construct an infinite number of
smooth structures on 4-manifolds satisfying certain conditions, but they do not
explicitly work out the circumstances under which two manifolds that arise from
their construction will fail to be diffeomorphic on the grounds of
Seiberg-Witten theory. This paper fills in that gap.


title: Finiteness and orbifold Vertex Operator Algebras

abstract:
  In this paper, I investigate the ascending chain condition of right ideals in
the case of vertex operator algebras satisfying a finiteness and/or a
simplicity condition. Possible applications to the study of finiteness of
orbifold VOAs is discussed.


title:
Controlled Sensing for Sequential Multihypothesis Testing with
  Controlled Markovian Observations and Non-Uniform Control Cost

abstract:
  A new model for controlled sensing for multihypothesis testing is proposed
and studied in the sequential setting. This new model, termed {\em controlled
Markovian observation} model, exhibits a more complicated memory structure in
the controlled observations than existing models. In addition, instead of
penalizing just the delay until the final decision time as in standard
sequential hypothesis testing problems, a much more general cost structure is
considered which entails accumulating the total control cost with respect to an
arbitrary control cost function. An asymptotically optimal test is proposed for
this new model and is shown to satisfy an {\em optimality} condition formulated
in terms of decision making risk. It is shown that the optimal causal control
policy for the controlled sensing problem is self-tuning, in the sense of
maximizing an inherent "inferential" reward simultaneously under every
hypothesis, with the maximal value being the best possible corresponding to the
case where the true hypothesis is known at the outset. Another test is also
proposed to meet {\em distinctly predefined} constraints on the various
decision risks {\em non-asymptotically,} while retaining asymptotic optimality.


title: On triangulating k-outerplanar graphs

abstract:
  A k-outerplanar graph is a graph that can be drawn in the plane without
crossing such that after k-fold removal of the vertices on the outer-face there
are no vertices left. In this paper, we study how to triangulate a
k-outerplanar graph while keeping its outerplanarity small. Specifically, we
show that not all k-outerplanar graphs can be triangulated so that the result
is k-outerplanar, but they can be triangulated so that the result is
(k+1)-outerplanar.


title:
Macroscopic State Interferometry Over Large Distances Using State
  Discrimination

abstract:
  The propagation of macroscopic entangled states over large distances in the
presence of loss is of fundamental interest and may have practical applications
as well. Here we describe two different techniques in which state
discrimination can be used to violate Bell's inequality with macroscopic
phase-entangled coherent states. We find that Bell's inequality can be violated
by these macroscopic states over a distance of approximately 400 km in
commercially-available optical fibers.


title:
Isogeometric finite element analysis of functionally graded plates using
  a refined plate theory

abstract:
  We propose in this paper a novel inverse tangent transverse shear deformation
formulation for functionally graded material (FGM) plates. The isogeometric
finite element analysis (IGA) of static, free vibration and buckling problems
of FGM plates is then addressed using a refined plate theory (RPT). The RPT
enables us to describe the non-linear distribution of shear stresses through
the plate thickness without any requirement of shear correction factors (SCF).
IGA utilizes basis functions, namely B-splines or non-uniform rational
B-splines (NURBS), which achieve easily the smoothness of any arbitrary order.
It hence satisfies the C1 requirement of the RPT model. The present method
approximates the displacement field of four degrees of freedom per each control
point and retains the computational efficiency while ensuring the high accuracy
in solution.


title:
Non-classical transport with angular-dependent path-length
  distributions. 2: Application to pebble bed reactor cores

abstract:
  We describe an analysis of neutron transport in the interior of model pebble
bed reactor (PBR) cores, considering both crystal and random pebble
arrangements. Monte Carlo codes were developed for (i) generating random
realizations of the model PBR core, and (ii) performing neutron transport
inside the crystal and random heterogeneous cores; numerical results are
presented for two different choices of material parameters. These numerical
results are used to investigate the anisotropic behavior of neutrons in each
case and to assess the accuracy of estimates for the diffusion coefficients
obtained with the diffusion approximations of different models: the atomic mix
model, the Behrens correction, the Lieberoth correction, the generalized linear
Boltzmann equation (GLBE), and the new GLBE with angular-dependent path-length
distributions. This new theory utilizes a non-classical form of the Boltzmann
equation in which the locations of the scattering centers in the system are
correlated and the distance-to-collision is not exponentially distributed; this
leads to an anisotropic diffusion equation. We show that the results predicted
using the new GLBE theory are extremely accurate, correctly identifying the
anisotropic diffusion in each case and greatly outperforming the other models
for the case of random systems.


title: Infinitary version of Pol-Inv Galois connection

abstract:
  In this article, we prove infinitary version of one to one correspondence
theorem between clones and relational clones on a fixed possibly infinite set.
We also characterize the relational clone corresponding to the clone of all
finitary operations. By this characterization, we obtain correspondence between
finitary clones on a fixed infinite set and relational clones satisfying some
condition.


title:
Limits on the spatial variations of the electron-to-proton mass ratio in
  the Galactic plane

abstract:
  Aims. To validate the Einstein equivalence principle (local position
invariance) by limiting the fractional changes in the electron-to-proton mass
ratio, mu = m_e/m_p, measured in Galactic plane objects. Methods. High
resolution spectral observations of dark clouds in the inversion line of
NH3(1,1) and pure rotational lines of other molecules (the so-called ammonia
method) were performed at the Medicina 32-m and the Effelsberg 100-m radio
telescopes to measure the radial velocity offsets, Delta RV = V_rot - V_inv,
between the rotational and inversion transitions which have different
sensitivities to the value of mu. Results. In our previous observations
(2008-2010), a mean offset of <Delta RV> = 0.027+/-0.010 km/s [3 sigma
confidence level (C.L.)] was measured. To test for possible hidden errors, we
carried out additional observations of a sample of molecular cores in
2010-2013. As a result, a systematic error in the radial velocities of an
amplitude ~0.02 km/s was revealed. The averaged offset between the radial
velocities of the rotational transitions of HC3N(2-1), HC5N(9-8), HC7N(16-15),
HC7N(21-20), and HC7N(23-22), and the inversion transition of NH3(1,1) <Delta
RV> = 0.003+/-0.018 km/s (3 sigma C.L.). This value, when interpreted in terms
of Delta mu/mu= (mu_obs - mu_lab)/mu_lab, constraints the mu-variation at the
level of Delta mu/mu < 2*10^{-8} (3 sigma C.L.), which is the most stringent
limit on the fractional changes in mu based on astronomical observations.


title: B-physics computations from Nf=2 tmQCD

abstract:
  We present an accurate lattice QCD computation of the b-quark mass, the B and
Bs decay constants, the B-mixing bag-parameters for the full four-fermion
operator basis, as well as estimates for \xi and f_{Bq}\sqrt{B_q} extrapolated
to the continuum limit and the physical pion mass. We have used Nf = 2
dynamical quark gauge configurations at four values of the lattice spacing
generated by ETMC. Extrapolation in the heavy quark mass from the charm to the
bottom quark region has been carried out using ratios of physical quantities
computed at nearby quark masses, having an exactly known infinite mass limit.


title:
Broadband Pulsations from PSR B1821-24: Implications for Emission Models
  and the Pulsar Population of M28

abstract:
  We report a 5.4\sigma\ detection of pulsed gamma rays from PSR B1821-24 in
the globular cluster M28 using ~44 months of Fermi Large Area Telescope (LAT)
data that have been reprocessed with improved instrument calibration constants.
We constructed a phase-coherent ephemeris, with post-fit residual RMS of 3 \mu
s, using radio data spanning ~23.2 years, enabling measurements of the
multi-wavelength light curve properties of PSR B1821-24 at the milliperiod
level. We fold RXTE observations of PSR B1821-24 from 1996 to 2007 and discuss
implications on the emission zones. The gamma-ray light curve consists of two
peaks, separated by 0.41$\pm$0.02 in phase, with the first gamma-ray peak
lagging the first radio peak by 0.05$\pm$0.02 in phase, consistent with the
phase of giant radio pulses. We observe significant emission in the off-peak
interval of PSR B1821-24 with a best-fit LAT position inconsistent with the
core of M28. We do not detect significant gamma-ray pulsations at the spin or
orbital periods from any other known pulsar in M28, and we place limits on the
number of energetic pulsars in the cluster. The derived gamma-ray efficiency,
~2%, is typical of other gamma-ray pulsars with comparable spin-down power,
suggesting that the measured spin-down rate ($2.2\times10^{36}$ erg s$^{-1}$)
is not appreciably distorted by acceleration in the cluster potential. This
confirms PSR B1821-24 as the second very energetic millisecond pulsar in a
globular cluster and raises the question of whether these represent a separate
class of objects that only form in regions of very high stellar density


title:
Cancer initiation with epistatic interactions between driver and
  passenger mutations

abstract:
  We investigate the dynamics of cancer initiation in a mathematical model with
one driver mutation and several passenger mutations. Our analysis is based on a
multi type branching process: We model individual cells which can either divide
or undergo apoptosis. In case of a cell division, the two daughter cells can
mutate, which potentially confers a change in fitness to the cell. In contrast
to previous models, the change in fitness induced by the driver mutation
depends on the genetic context of the cell, in our case on the number of
passenger mutations. The passenger mutations themselves have no or only a very
small impact on the cell's fitness. While our model is not designed as a
specific model for a particular cancer, the underlying idea is motivated by
clinical and experimental observations in Burkitt Lymphoma. In this tumor, the
hallmark mutation leads to deregulation of the MYC oncogene which increases the
rate of apoptosis, but also the proliferation rate of cells. This increase in
the rate of apoptosis hence needs to be overcome by mutations affecting
apoptotic pathways, naturally leading to an epistatic fitness landscape. This
model shows a very interesting dynamical behavior which is distinct from the
dynamics of cancer initiation in the absence of epistasis. Since the driver
mutation is deleterious to a cell with only a few passenger mutations, there is
a period of stasis in the number of cells until a clone of cells with enough
passenger mutations emerges. Only when the driver mutation occurs in one of
those cells, the cell population starts to grow rapidly.


title: Using 3D Voronoi grids in radiative transfer simulations

abstract:
  Probing the structure of complex astrophysical objects requires effective
three-dimensional (3D) numerical simulation of the relevant radiative transfer
(RT) processes. As with any numerical simulation code, the choice of an
appropriate discretization is crucial. Adaptive grids with cuboidal cells such
as octrees have proven very popular, however several recently introduced
hydrodynamical and RT codes are based on a Voronoi tessellation of the spatial
domain. Such an unstructured grid poses new challenges in laying down the rays
(straight paths) needed in RT codes. We show that it is straightforward to
implement accurate and efficient RT on 3D Voronoi grids. We present a method
for computing straight paths between two arbitrary points through a 3D Voronoi
grid in the context of a RT code. We implement such a grid in our RT code
SKIRT, using the open source library Voro++ to obtain the relevant properties
of the Voronoi grid cells based solely on the generating points. We compare the
results obtained through the Voronoi grid with those generated by an octree
grid for two synthetic models, and we perform the well-known Pascucci RT
benchmark using the Voronoi grid. The presented algorithm produces correct
results for our test models. Shooting photon packages through the geometrically
much more complex 3D Voronoi grid is only about three times slower than the
equivalent process in an octree grid with the same number of cells, while in
fact the total number of Voronoi grid cells may be lower for an equally good
representation of the density field. We conclude that the benefits of using a
Voronoi grid in RT simulation codes will often outweigh the somewhat slower
performance.


title: Early Fire Detection Using HEP and Space-time Analysis

abstract:
  In this article, a video base early fire alarm system is developed by
monitoring the smoke in the scene. There are two major contributions in this
work. First, to find the best texture feature for smoke detection, a general
framework, named Histograms of Equivalent Patterns (HEP), is adopted to achieve
an extensive evaluation of various kinds of texture features. Second, the
\emph{Block based Inter-Frame Difference} (BIFD) and a improved version of
LBP-TOP are proposed and ensembled to describe the space-time characteristics
of the smoke. In order to reduce the false alarms, the Smoke History Image
(SHI) is utilized to register the recent classification results of candidate
smoke blocks. Experimental results using SVM show that the proposed method can
achieve better accuracy and less false alarm compared with the state-of-the-art
technologies.


title:
Multi-resonance orbital model applied to high-frequency quasi-periodic
  oscillations observed in Sgr A*

abstract:
  The multi-resonance orbital model of high-frequency quasi-periodic
oscillations (HF QPOs) enables precise determination of the black hole
dimensionless spin a if observed set of oscillations demonstrates three (or
more) commensurable frequencies. The black hole spin is related to the
frequency ratio only, while its mass M is related to the frequency magnitude.
The model is applied to the triple frequency set of HF QPOs observed in Sgr A*
source with frequency ratio 3:2:1. Acceptable versions of the multi-resonance
model are determined by the restrictions on the Sgr A* supermassive black hole
mass. Among the best candidates the version of strong resonances related to the
black hole "magic" spin a=0.983 belongs. However, the version demonstrating the
best agreement with the mass restrictions predicts spin a=0.980.


title: Predictor-Based Tracking For Neuromuscular Electrical Stimulation

abstract:
  A new hybrid tracking controller for neuromuscular electrical stimulation is
proposed. The control scheme uses sampled measurements and is designed by
utilizing a numerical prediction of the state variables. The tracking error of
the closed-loop system converges exponentially to zero and robustness to
perturbations of the sampling schedule is exhibited. One of the novelties of
our approach is the ability to satisfy a state constraint imposed by the
physical system.


title: Quaternion quadratic equations in characteristic 2

abstract:
  In this paper we present a solution for any standard quaternion quadratic
equation, i.e. an equation of the form $z^2+\mu z+\nu=0$ where $\mu$ and $\nu$
belong to some quaternion division algebra $Q$ over some field $F$, assuming
the characteristic of $F$ is $2$.


title:
Supersymmetry and Dark Matter post LHC8: why we may expect both axion
  and WIMP detection

abstract:
  In the post-LHC8 era, it is perceived that what is left of SUSY model
parameter space is highly finetuned in the EW sector (EWFT). We discuss how
conventional measures overestimate EWFT in SUSY theory. Radiatively-driven
natural SUSY (RNS) models maintain the SUSY GUT paradigm with low EWFT at 10%
level, but are characterized by light higgsinos ~100-300 GeV and a thermal
underabundance of WIMP dark matter. Implementing the SUSY DFSZ solution to the
strong CP problem explains the small \mu parameter but indicates dark matter
should be comprised mainly of axions with a small admixture of higgsino-like
WIMPs. While RNS might escape LHC14 searches, we would expect ultimately direct
detection of both WIMPs and axions. An e^+e^- collider with \sqrt{s} ~ 500-600
GeV should provide a thorough search for the predicted light higgsinos.


title: The rigidity of infinite graphs

abstract:
  A rigidity theory is developed for the Euclidean and non-Euclidean placements
of countably infinite simple graphs in R^d with respect to the classical l^p
norms, for d>1 and 1<p<\infty. Generalisations are obtained for the Laman and
Henneberg combinatorial characterisations of generic infinitesimal rigidity for
finite graphs in the Euclidean plane. Also Tay's multi-graph characterisation
of the rigidity of generic finite body-bar frameworks in d-dimensional
Euclidean space is generalised to the non-Euclidean l^p norms and to countably
infinite graphs. For all dimensions and norms it is shown that a generically
rigid countable simple graph is the direct limit of an inclusion tower of
finite graphs for which the inclusions satisfy a relative rigidity property.
For d>2 a countable graph which is rigid for generic placements in R^d may fail
the stronger property of sequential rigidity, while for d=2 the equivalence
with sequential rigidity is obtained from the generalised Laman
characterisations. Applications are given to the flexibility of non-Euclidean
convex polyhedra and to the infinitesimal and continuous rigidity of compact
infinitely-faceted simplicial polytopes.


title: Physical-Layer Cryptography Through Massive MIMO

abstract:
  We propose the new technique of physical-layer cryptography based on using a
massive MIMO channel as a key between the sender and desired receiver, which
need not be secret. The goal is for low-complexity encoding and decoding by the
desired transmitter-receiver pair, whereas decoding by an eavesdropper is hard
in terms of prohibitive complexity. The decoding complexity is analyzed by
mapping the massive MIMO system to a lattice. We show that the eavesdropper's
decoder for the MIMO system with M-PAM modulation is equivalent to solving
standard lattice problems that are conjectured to be of exponential complexity
for both classical and quantum computers. Hence, under the widely-held
conjecture that standard lattice problems are hard to solve in the worst-case,
the proposed encryption scheme has a more robust notion of security than that
of the most common encryption methods used today such as RSA and
Diffie-Hellman. Additionally, we show that this scheme could be used to
securely communicate without a pre-shared secret and little computational
overhead. Thus, by exploiting the physical layer properties of the radio
channel, the massive MIMO system provides for low-complexity encryption
commensurate with the most sophisticated forms of application-layer encryption
that are currently known.


title: Desingularization of regular algebras

abstract:
  We identify families of commutative rings that can be written as a direct
limit of a directed system of noetherian regular rings and investigate the
homological properties of such rings.


title: Empowerment -- an Introduction

abstract:
  This book chapter is an introduction to and an overview of the
information-theoretic, task independent utility function "Empowerment", which
is defined as the channel capacity between an agent's actions and an agent's
sensors. It quantifies how much influence and control an agent has over the
world it can perceive. This book chapter discusses the general idea behind
empowerment as an intrinsic motivation and showcases several previous
applications of empowerment to demonstrate how empowerment can be applied to
different sensor-motor configuration, and how the same formalism can lead to
different observed behaviors. Furthermore, we also present a fast approximation
for empowerment in the continuous domain.


title: Laplacian flow of closed $G_2$-structures inducing nilsolitons

abstract:
  We study the existence of left invariant closed $G_2$-structures defining a
Ricci soliton metric on simply connected nonabelian nilpotent Lie groups.
  For each one of these $G_2$-structures, we show long time existence and
uniqueness of solution for the Laplacian flow on the noncompact manifold.
Moreover, considering the Laplacian flow on the associated Lie algebra as a
bracket flow on $\R^7$ in a similar way as in [23] we prove that the underlying
metrics $g(t)$ of the solution converge smoothly, up to pull-back by
time-dependent diffeomorphisms, to a flat metric, uniformly on compact sets in
the nilpotent Lie group, as $t$ goes to infinity.


title: Notes on Hilbert's 16th: experiencing Viro's theory

abstract:
  This text is intended to become in the long run Chapter 3 of our long saga
dedicated to Riemann, Ahlfors and Rohlin. Yet, as its contents evolved as
mostly independent (due to our inaptitude to interconnect both trends as
strongly as we wished), it seemed preferable to publish it separately. More
factually, our account is an attempt to get familiarized with the current
consensus about Hilbert's 16th in degree 8. This is a nearly finished piece of
mathematics, thanks heroic breakthroughs by Viro, Fiedler, Korchagin, Shustin,
Chevallier, Orevkov, yet still leaving undecided six tantalizing bosons among a
menagerie of 104 logically possible distributions of ovals (respecting
B\'ezout, Gudkov periodicity, and the Fiedler-Viro imparity law sieving away
4+36 schemes). This quest inevitably involves glimpsing deep into the nebula
referrable to as Viro's patchworking, and the likewise spectacular
obstructional laws of Fiedler, Viro, Shustin, Orevkov. In the overall, the game
is much comparable to a pigeons hunting video-game, where 144 birds are
liberated in nature, with some of them strong enough to fly higher and higher
in the blue sky as to rejoin the stratospheric paradise of eternal life
(construction of a scheme in the algebro-geometric category). Some other, less
fortunate, birds were killed (a long time ago) and crashed down miserably over
terrestrial crust (prohibition). Alas, the hunt is unfinished with still six
birds, apparently too feeble to rally safely the paradise, yet too acrobatic
for any homosapiens being skillful enough to shoot them down.


title: Dimensionality driven charge density wave instability in TiS$_2$

abstract:
  Density functional theory and density functional perturbation theory are used
to investigate the electronic and vibrational properties of TiS$_2$. Within the
local density approximation the material is a semi-metal both in the bulk and
in the monolayer form. Most interestingly we observe a Kohn anomaly in the bulk
phonon dispersion, which turns into a charge density wave instability when
TiS$_2$ is thinned to less than four monolayers. Such charge density wave phase
can be tuned by compressive strain, which appears to be the control parameter
of the instability.


title:
Mean Field Bayes Backpropagation: scalable training of multilayer neural
  networks with binary weights

abstract:
  Significant success has been reported recently using deep neural networks for
classification. Such large networks can be computationally intensive, even
after training is over. Implementing these trained networks in hardware chips
with a limited precision of synaptic weights may improve their speed and energy
efficiency by several orders of magnitude, thus enabling their integration into
small and low-power electronic devices. With this motivation, we develop a
computationally efficient learning algorithm for multilayer neural networks
with binary weights, assuming all the hidden neurons have a fan-out of one.
This algorithm, derived within a Bayesian probabilistic online setting, is
shown to work well for both synthetic and real-world problems, performing
comparably to algorithms with real-valued weights, while retaining
computational tractability.


title:
A stochastic approach to the harmonic map heat flow on manifolds with
  time-dependent Riemannian metric

abstract:
  We first prove stochastic representation formulae for space-time harmonic
mappings defined on manifolds with evolving Riemannian metric. We then apply
these formulae to derive Liouville type theorems under appropriate curvature
conditions. Space-time harmonic mappings which are defined globally in time
correspond to ancient solutions to the harmonic map heat flow. As corollaries,
we establish triviality of such ancient solutions in a variety of different
situations.


title: Singular Value Decomposition of Images from Scanned Photographic Plates

abstract:
  We want to approximate the mxn image A from scanned astronomical photographic
plates (from the Sofia Sky Archive Data Center) by using far fewer entries than
in the original matrix. By using rank of a matrix, k we remove the redundant
information or noise and use as Wiener filter, when rank k<m or k<n. With this
approximation more than 98% compression ration of image of astronomical plate
without that image details, is obtained. The SVD of images from scanned
photographic plates (SPP) is considered and its possible image compression.


title:
Prospects of Direct Growth Boron Nitride Films as Substrates for
  Graphene Electronics

abstract:
  We present a route for direct growth of boron nitride via a polyborazylene to
h-BN conversion process. This two-step growth process ultimately leads to a
>25x reduction in the RMS surface roughness of h-BN films when compared to a
high temperature growth on Al2O3(0001) and Si(111) substrates. Additionally,
the stoichiometry is shown to be highly dependent on the initial polyborazylene
deposition temperature. Importantly, CVD graphene transferred to direct-grown
boron nitride films on Al2O3 at 400{\deg}C results in a >1.5x and >2.5x
improvement in mobility compared to CVD graphene transferred to Al2O3 and SiO2
substrates, respectively, which is attributed to the combined reduction of
remote charged impurity scattering and surface roughness scattering. Simulation
of mobility versus carrier concentration confirms the importance of limiting
the introduction of charged impurities in the h-BN film and highlights the
importance of these results in producing optimized h-BN substrates for high
performance graphene and TMD devices.


title: Axisymmetric multiphase lattice Boltzmann method

abstract:
  A lattice Boltzmann method for axisymmetric multiphase flows is presented and
validated. The method is capable of accurately modeling flows with variable
density. We develop the classic Shan-Chen multiphase model [ Phys. Rev. E 47
1815 (1993)] for axisymmetric flows. The model can be used to efficiently
simulate single and multiphase flows. The convergence to the axisymmetric
Navier-Stokes equations is demonstrated analytically by means of a
Chapmann-Enskog expansion and numerically through several test cases. In
particular, the model is benchmarked for its accuracy in reproducing the
dynamics of the oscillations of an axially symmetric droplet and on the
capillary breakup of a viscous liquid thread. Very good quantitative agreement
between the numerical solutions and the analytical results is observed.


title: Complex absorbing potential method for the perturbed Dirac operator

abstract:
  The Complex Absorbing Potential (CAP) method is widely used to compute
resonances in Quantum Chemistry, both for nonrelativistic and relativistic
Hamiltonians. In the semiclassical limit $\hbar \to 0$ we consider resonances
near the real axis and we establish the CAP method rigorously for the perturbed
Dirac operator by proving that individual resonances are perturbed eigenvalues
of the nonselfadjoint CAP Hamiltonian, and vice versa. The proofs are based on
pseudodifferential operator theory and microlocal analysis.


title: Measurement of $\gamma$ from three-body B decays

abstract:
  Using the BaBar measurements of the Dalitz plots for the decays $B^0 \to
K^+\pi^0\pi^-$, $B^0 \to K^0\pi^+\pi^-$, $B^+ \to K^+\pi^+\pi^-$, $B^0 \to K^+
K^0 K^-$, and $B^0 \to K^0 K^0 \bar K^0$, we demonstrate that it is possible to
cleanly extract the weak phase $\gamma$. An advantage of this Dalitz-plot
method is that one can obtain many independent measurements of $\gamma$,
thereby reducing its statistical error. An accurate determination of the
errors, however, requires detailed knowledge of the data. Hopefully, an
experimental group will repeat the analysis, and obtain precise values of the
errors.


title:
Distributed $n$-player approachability and consensus in coalitional
  games

abstract:
  We study a distributed allocation process where, repeatedly in time, every
player renegotiates past allocations with neighbors and allocates new revenues.
The average allocations evolve according to a doubly (over time and space)
averaging algorithm. We study conditions under which the average allocations
reach consensus to any point within a predefined target set even in the
presence of adversarial disturbances. Motivations arise in the context of
coalitional games with transferable utilities (TU) where the target set is any
set of allocations that make the grand coalitions stable.


title: Cardy algebras and sewing constraints, II

abstract:
  This is the part II of a two-part work started in arXiv:0807.3356 [math.QA].
In part I, Cardy algebras were studied, a notion which arises from the
classification of genus-0,1 open-closed rational conformal field theories. In
this part, we prove that a Cardy algebra also satisfies the higher genus
factorisation and modular-invariance properties formulated in
arXiv:hep-th/0612306 in terms of the notion of a solution to the sewing
constraints. We present the proof by showing that the latter notion, which is
defined as a monoidal natural transformation, can be expressed in terms of
generators and relations, which correspond exactly to the defining data and
axioms of a Cardy algebra.


title:
A hierarchy of exactly solvable spin-1/2 chains with so(N)_1 critical
  points

abstract:
  We construct a hierarchy of exactly solvable spin-1/2 chains with so(N)_1
critical points. Our construction is based on the framework of
condensate-induced transitions between topological phases. We employ this
framework to construct a Hamiltonian term that couples N transverse field Ising
chains such that the resulting theory is critical and described by the so(N)_1
conformal field theory. By employing spin duality transformations, we then cast
these spin chains for arbitrary N into translationally invariant forms that all
allow exact solution by the means of a Jordan-Wigner transformation. For odd N
our models generalize the phase diagram of the transverse field Ising chain,
the simplest model in our hierarchy. For even N the models can be viewed as
longer ranger generalizations of the XY chain, the next model in the hierarchy.
We also demonstrate that our method of constructing spin chains with given
critical points goes beyond exactly solvable models. Applying the same strategy
to the Blume-Capel model, a spin-1 generalization of the Ising chain in a
generic magnetic field, we construct another critical spin-1 chain with the
predicted CFT describing the criticality.


title: On left-orderability and double branched covers of Kanenobu's knots

abstract:
  We show that the fundamental group of the double branched cover of an
infinite family of homologically thin, non-quasi-alternating knots is not
left-orderable, giving further support for a conjecture of Boyer, Gordon, and
Watson that an irreducible rational homology 3-sphere is an L-space if and only
if its fundamental group is not left-orderable.


title: Estimation for Unit Root Testing

abstract:
  We revisit estimation and computation of the Dickey Fuller (DF) and DF-type
tests. Firstly, we show that the usual one step approach, based on the "DF
autoregression", is likely to be subject to misspecification. Secondly, we
clarify a neglected two step approach for estimation of the DF test. (In fact,
we introduce a new two step DF autoregression.) This method is always correctly
specified and efficient under the circumstances. However, it is either
neglected or misused in unit root testing literature. The commonly employed
hybrid of the (correct) two step method is shown to be inefficient, even
asymptotically. Finally, we further improve/robustify the proposed two step
method by employing the missing initial observations. Our finally proposed
method is to be used in unit root testing, since it is a new DF autoregression
that retains the missing observations.


title: Graphs with the Fewest Matchings

abstract:
  In recent years there has been increased interest in extremal problems for
"counting" parameters of graphs. For example, the Kahn-Zhao theorem gives an
upper bound on the number of independent sets in a $d$-regular graph. In the
same spirit, the Upper Matching Conjecture claims an upper bound on the number
of $k$-matchings in a $d$-regular graph. Here we consider both matchings and
matchings of fixed sizes in graphs with a given number vertices and edges. We
prove that the graph with the fewest matchings is either the lex or the colex
graph. Similarly, for fixed $k$, the graph with the fewest $k$-matchings is
either the lex or the colex graph. To prove these results we first prove that
the lex bipartite graph has the fewest matchings of all sizes among bipartite
graphs with fixed part sizes and a given number of edges.


title: Cosmological models and stability

abstract:
  Principles in the form of heuristic guidelines or generally accepted dogma
play an important role in the development of physical theories. In particular,
philosophical considerations and principles figure prominently in the work of
Albert Einstein. As mentioned in the talk by Jiri Bicak at this conference
Einstein formulated the equivalence principle, an essential step on the road to
general relativity, during his time in Prague 1911-1912. In this talk, I would
like to discuss some aspects of cosmological models. As cosmology is an area of
physics where "principles" such as the "cosmological principle" or the
"Copernican principle" play a prominent role in motivating the class of models
which form part of the current standard model, I will start by comparing the
role of the equivalence principle to that of the principles used in cosmology.
I will then briefly describe the standard model of cosmology to give a
perspective on some mathematical problems and conjectures on cosmological
models, which are discussed in the later part of this paper.


title: Convex Poincar\'e inequality

abstract:
  We characterize the symmetric measures which satisfy the one dimensional
convex Poincar\'e inequality. For these measures the tenesorization argument
yields concentration inequalities for their products and convex sets in R^n.


title: Implicit transaction costs and the fundamental theorems of asset pricing

abstract:
  This paper studies arbitrage pricing theory in financial markets with
implicit transaction costs. We extend the existing theory to include the more
realistic possibility that the price at which the investors trade is dependent
on the traded volume. The investors in the market always buy at the ask and
sell at the bid price. Implicit transaction costs are composed of two terms,
one is able to capture the bid-ask spread, and the second the price impact.
Moreover, a new definition of a self-financing portfolio is obtained. The
self-financing condition suggests that continuous trading is possible, but is
restricted to predictable trading strategies having c\'adl\'ag
(right-continuous with left limits) and c\'agl\'ad (left-continuous with right
limits) paths of bounded quadratic variation and of finitely many jumps. That
is, c\'adl\'ag and c\'agl\'ad predictable trading strategies of infinite
variation, with finitely many jumps and of finite quadratic variation are
allowed in our setting. Restricting ourselves to c\'agl\'ad predictable trading
strategies, we show that the existence of an equivalent probability measure is
equivalent to the absence of arbitrage opportunities, so that the first
fundamental theorem of asset pricing (FFTAP) holds. It is also shown that the
use of continuous and bounded variation trading strategies can improve the
efficiency of hedging in a market with implicit transaction costs. To better
understand how to apply the theory proposed we provide an example of an
implicit transaction cost economy that is linear and non-linear in the order
size.


title:
Transport in a chain of asymmetric cavities: Effects of the
  concentration with hard-core interaction

abstract:
  We studied the transport process of overdamped Brownian particles, in a chain
of asymmetric cavities, interacting through a hard-core potential. When a force
is applied in opposite directions a difference in the drift velocity of the
particles inside the cavity can be observed. Previous works on similar systems
deal with the low concentration regime, in which the interaction is irrelevant.
In this case it was found that large particles show a stronger asymmetry in the
drift velocity when a small force is applied, allowing for the separation of
different size particles (Reguera et al., Phys. Rev. Lett 108, 020604, 2012).
We found that when the interaction between particles is considered, the
behavior of the system is substantially different. For example, as
concentration is increased, the small particles are the ones that show a
stronger asymmetry. For the case where all the particles in the system are of
the same size we took advantage of the particle-vacancy analogy to predict that
the left and right currents are almost equal in a region around the
concentration 0.5 despite the asymmetry of the cavity.


title:
Background identification and suppression for the measurement of (n,g)
  reactions with the DANCE array at LANSCE

abstract:
  In the commissioning phase of the DANCE project (Detector for Advanced
Neutron Capture Experiments) measurements have been performed with special
emphasis on the identification and suppression of possible backgrounds for the
planned (n,g) experiments. This report describes several background sources,
observed in the experiment or anticipated from simulations, which will need to
be suppressed in this and in similar detectors that are planned at other
facilities. First successes are documented in the suppression of background
from scattered neutrons captured in the detector as well as from the internal
radiation. Experimental results and simulations using the GEANT code are
compared.


title:
Bayes-X: a Bayesian inference tool for the analysis of X-ray
  observations of galaxy clusters

abstract:
  We present the first public release of our Bayesian inference tool, Bayes-X,
for the analysis of X-ray observations of galaxy clusters. We illustrate the
use of Bayes-X by analysing a set of four simulated clusters at z=0.2-0.9 as
they would be observed by a Chandra-like X-ray observatory. In both the
simulations and the analysis pipeline we assume that the dark matter density
follows a spherically-symmetric Navarro, Frenk and White (NFW) profile and that
the gas pressure is described by a generalised NFW (GNFW) profile. We then
perform four sets of analyses. By numerically exploring the joint probability
distribution of the cluster parameters given simulated Chandra-like data, we
show that the model and analysis technique can robustly return the simulated
cluster input quantities, constrain the cluster physical parameters and reveal
the degeneracies among the model parameters and cluster physical parameters. We
then analyse Chandra data on the nearby cluster, A262, and derive the cluster
physical profiles. To illustrate the performance of the Bayesian model
selection, we also carried out analyses assuming an Einasto profile for the
matter density and calculated the Bayes factor. The results of the model
selection analyses for the simulated data favour the NFW model as expected.
However, we find that the Einasto profile is preferred in the analysis of A262.
The Bayes-X software, which is implemented in Fortran 90, is available at
http://www.mrao.cam.ac.uk/facilities/software/bayesx/.


title:
Translation invariant pure state on $\clb=\otimes_{\IZ}M_d(\IC)$ and its
  split property

abstract:
  We prove that a real lattice symmetric reflection positive translation
invariant pure state of $\clb=\otimes_{\IZ}M_d(\IC)$ is a split state if its
two points spatial correlations functions decay exponentially.


title: Cooperads as Symmetric Sequences

abstract:
  We give a brief overview of the basics of cooperad theory using a new
definition which lends itself to easy example creation and verification. We
also apply our definition to build the parenthesization and cosimplicial
structures exhibited by cooperads and give examples.


title: Comparing Fr\'echet and positive stable laws

abstract:
  Let ${\bf L}$ be the unit exponential random variable and ${\bf Z}_\alpha$
the standard positive $\alpha$-stable random variable. We prove that
$\{(1-\alpha) \alpha^{\gamma_\alpha} {\bf Z}_\alpha^{-\gamma_\alpha}, 0< \alpha
<1\}$ is decreasing for the optimal stochastic order and that $\{(1-\alpha){\bf
Z}_\alpha^{-\gamma_\alpha}, 0< \alpha < 1\}$ is increasing for the convex
order, with $\gamma_\alpha = \alpha/(1-\alpha).$ We also show that
$\{\Gamma(1+\alpha) {\bf Z}_\alpha^{-\alpha}, 1/2\le \alpha \le 1\}$ is
decreasing for the convex order, that ${\bf Z}_\alpha^{-\alpha}\,\prec_{st}\,
\Gamma(1-\alpha) \L$ and that $\Gamma(1+\a){\bf Z}_\alpha^{-\alpha}
\,\prec_{cx}\,{\bf L}.$ This allows to compare ${\bf Z}_\alpha$ with the two
extremal Fr\'echet distributions corresponding to the behaviour of its density
at zero and at infinity. We also discuss the applications of these bounds to
the strange behaviour of the median of ${\bf Z}_\alpha$ and ${\bf
Z}_\alpha^{-\alpha}$ and to some uniform estimates on the classical
Mittag-Leffler function. Along the way, we obtain a canonical factorization of
${\bf Z}_\alpha$ for $\alpha$ rational in terms of Beta random variables. The
latter extends to the one-sided branches of real strictly stable densities.


title: A Comprehensive X-ray Absorption Model for Atomic Oxygen

abstract:
  An analytical formula is developed to represent accurately the
photoabsorption cross section of O I for all energies of interest in X-ray
spectral modeling. In the vicinity of the Kedge, a Rydberg series expression is
used to fit R-matrix results, including important orbital relaxation effects,
that accurately predict the absorption oscillator strengths below threshold and
merge consistently and continuously to the above-threshold cross section.
Further minor adjustments are made to the threshold energies in order to
reliably align the atomic Rydberg resonances after consideration of both
experimental and observed line positions. At energies far below or above the
K-edge region, the formulation is based on both outer- and inner-shell direct
photoionization, including significant shake-up and shake-off processes that
result in photoionization-excitation and double photoionization contributions
to the total cross section. The ultimate purpose for developing a definitive
model for oxygen absorption is to resolve standing discrepancies between the
astronomically observed and laboratory measured line positions, and between the
inferred atomic and molecular oxygen abundances in the interstellar medium from
XSTAR and SPEX spectral models.


title:
Investigation of collective radial expansion and stopping in heavy ion
  collisions at Fermi energies

abstract:
  We present an analysis of multifragmentation events observed in central Xe+Sn
reactions at Fermi energies. Performing a comparison between the predictions of
the Stochastic Mean Field (SMF) transport model and experimental data, we
investigate the impact of the compression-expansion dynamics on the properties
of the final reaction products. We show that the amount of radial collective
expansion, which characterizes the dynamical stage of the reaction, influences
directly the onset of multifragmentation and the kinematic properties of
multifragmentation events. For the same set of events we also undertake a shape
analysis in momentum space, looking at the degree of stopping reached in the
collision, as proposed in recent experimental studies. We show that full
stopping is achieved for the most central collisions at Fermi energies.
However, considering the same central event selection as in the experimental
data, we observe a similar behavior of the stopping power with the beam energy,
which can be associated with a change of the fragmentation mechanism, from
statistical to prompt fragment emission.


title:
Every list-decodable code for high noise has abundant near-optimal rate
  puncturings

abstract:
  We show that any q-ary code with sufficiently good distance can be randomly
punctured to obtain, with high probability, a code that is list decodable up to
radius $1 - 1/q - \epsilon$ with near-optimal rate and list sizes. Our results
imply that "most" Reed-Solomon codes are list decodable beyond the Johnson
bound, settling the long-standing open question of whether any Reed Solomon
codes meet this criterion.
  More precisely, we show that a Reed-Solomon code with random evaluation
points is, with high probability, list decodable up to radius $1 - \epsilon$
with list sizes $O(1/\epsilon)$ and rate $\Omega(\epsilon)$. As a second
corollary of our argument, we obtain improved bounds on the list decodability
of random linear codes over large fields.
  Our approach exploits techniques from high dimensional probability. Previous
work used similar tools to obtain bounds on the list decodability of random
linear codes, but the bounds did not scale with the size of the alphabet. In
this paper, we use a chaining argument to deal with large alphabet sizes.


title:
The role of the accretion disk, dust, and jets in the IR emission of
  low-luminosity AGN

abstract:
  We use recent high-resolution infrared (IR; 1 - 20 micron) photometry to
examine the origin of the IR emission in low-luminosity active galactic nuclei
(LLAGN). The data are compared with published model fits that describe the
spectral energy distribution of LLAGN in terms of an advection-dominated
accretion flow (ADAF), truncated thin accretion disk, and jet. The truncated
disk in these models is usually not luminous enough to explain the observed IR
emission, and in all cases its spectral shape is much narrower than the broad
IR peaks in the data. Synchrotron radiation from the jet appears to be
important in very radio-loud nuclei, but the detection of strong silicate
emission features in many objects indicates that dust must also contribute. We
investigate this point by fitting the IR SED of NGC 3998 using dusty torus and
optically thin (tau_MIR ~ 1) dust shell models. While more detailed modeling is
necessary, these initial results suggest that dust may account for the nuclear
mid-IR emission of many LLAGN.


title: Abundances in Stars with Debris Disks

abstract:
  We present preliminary results of a detailed chemical abundance analysis for
a sample of solar-type stars known to exhibit excess infrared emission
associated with dusty debris disks. Our sample of 28 stars was selected based
on results from the Formation and Evolution of Planetary Systems (FEPS) Spitzer
Legacy Program, for the purpose of investigating whether the stellar
atmospheres have been polluted with planetary material, which could indicate
that the metallicity enhancement in stars with planets is due to metal-rich
infall in the later stages of star and planet formation. The preliminary
results presented here consist of precise abundances for 15 elements (C, O, Na,
Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Fe, Co, and Ni) for half of the stars in our
sample. We find that none of the stars investigated so far exhibit the expected
trend of increasing elemental abundance with increasing condensation
temperature, which would result from the stars having accreted planetary
debris. Rather, the slopes of linear least-squares fits to the abundance data
are either negative or consistent with zero. In both cases, our results may
indicate that, like the Sun, the debris disk host stars are deficient in
refractory elements, a possible signature of terrestrial and/or gas giant
planet formation.


title: Pulsar Lightcurves

abstract: Energy-resolved lightcurves are calculated for a weak pulsar.


title: A 2-category of chronological cobordisms and odd Khovanov homology

abstract:
  We create a framework for odd Khovanov homology in the spirit of Bar-Natan's
construction for the ordinary Khovanov homology. Namely, we express the cube of
resolutions of a link diagram as a diagram in a certain 2-category of
chronological cobordisms and show that it is 2-commutative: the composition of
2-morphisms along any 3-dimensional subcube is trivial. This allows us to
create a chain complex, whose homotopy type modulo certain relations is a link
invariant. Both the original and the odd Khovanov homology can be recovered
from this construction by applying certain strict 2-functors. We describe other
possible choices of functors, including the one that covers both homology
theories and another generalizing dotted cobordisms to the odd setting. Our
construction works as well for tangles and is conjectured to be functorial up
to sign with respect to tangle cobordisms.


title: TSP Tours in Cubic Graphs: Beyond 4/3

abstract:
  After a sequence of improvements Boyd, Sitters, van der Ster, and Stougie
proved that any 2-connected graph whose n vertices have degree 3, i.e., a cubic
2-connected graph, has a Hamiltonian tour of length at most (4/3)n,
establishing in particular that the integrality gap of the subtour LP is at
most 4/3 for cubic 2-connected graphs and matching the conjectured value of the
famous 4/3 conjecture. In this paper we improve upon this result by designing
an algorithm that finds a tour of length (4/3 - 1/61236)n, implying that cubic
2-connected graphs are among the few interesting classes of graphs for which
the integrality gap of the subtour LP is strictly less than 4/3. With the
previous result, and by considering an even smaller epsilon, we show that the
integrality gap of the TSP relaxation is at most 4/3 - epsilon, even if the
graph is not 2-connected (i.e. for cubic connected graphs), implying that the
approximability threshold of the TSP in cubic graphs is strictly below 4/3.
Finally, using similar techniques we show, as an additional result, that every
Barnette graph admits a tour of length at most (4/3 - 1/18)n.


title: Circuit QED - Lecture Notes

abstract:
  The new and rapidly growing field of circuit QED offers extremely exciting
prospects for learning about and exercising intimate control over quantum
systems, providing flexible, engineerable design and strong nonlinearities and
interactions in systems consisting of microwave radiation fields and fixed
artificial "atoms". These notes aim to provide a non-expert introduction to the
field of circuit QED, to give a basic appreciation of the promise and
challenges of the field, along with a number of key concepts that will
hopefully be useful for the reader who is new to the field and beginning to
explore the research literature. They were written as a pedagogical text
designed to complement a course delivered to third-year undergraduate students.
  After a introductory section which discusses why studying circuit QED might
be worthwhile and interesting, I introduce the basic theory tools from quantum
optics and quantum information which are needed to understand the key elements
of circuit QED. I also provide a brief overview of superconductivity, focussing
on the concepts which are most relevant to operation in the regimes of interest
in circuit QED. I then describe the three main types of superconducting qubits,
and finally give a basic introduction to decoherence and mixture and how they
relate to quantum behaviour in electronic circuits.


title:
The dependence of the evolution of SN type Ia progenitors on the C
  burning rate uncertainty and parameters of convective boundary mixing

abstract:
  Evolution of a supernova type Ia progenitor requires formation of a CO white
dwarf, which implies a dependence on the C burning rate (CBR). It can also be
affected by the recently identified possibility of C flame quenching by
convective boundary mixing. We present first results of our study of the
combined effect of these two potential sources of uncertainty on the SN Ia
progenitor evolution. We consider the possibility that the CBR is higher than
its currently recommended value by as much as a factor of 1000 if unidentified
resonances are important, or that it is significantly lower because of the
hindrance effect. For stellar models that assume the Schwarzschild boundary for
convection, the maximum initial mass for the formation of CO WDs increases from
M_i ~ 5.5 Msun for the CBR factor of 1000 to M_i > 7.0 Msun for the CBR factor
of 0.01. For C-flame quenching models, hybrid C-O-Ne WDs form for a range of
initial mass of Delta M_i ~ 1 Msun, which increases a fraction of stars that
form WDs capable of igniting C in a thermonuclear runaway. The most extreme
case is found for the CBR factor of 0.1 that is supported by the hindrance
model. This nuclear physics assumption, combined with C flame quenching, leads
to the formation of a hybrid C-O-Ne WD with a mass of 1.3 Msun. Such WDs do not
need to accrete much mass to reach the Chandrasekhar limit.


title: Long-time relaxation in pilot-wave theory

abstract:
  We initiate the study of relaxation to quantum equilibrium over long
timescales in pilot-wave theory. We simulate the time evolution of the
coarse-grained H-function Hbar(t) for a two-dimensional harmonic oscillator.
For a (periodic) wave function that is a superposition of the first 25 energy
states we confirm an approximately exponential decay of Hbar over five periods.
For a superposition of only the first four energy states we are able to
calculate Hbar(t) over 50 periods. We find that, depending on the set of phases
in the initial wave function, Hbar can decay to a large nonequilibrium residue
exceeding 10% of its initial value or it can become indistinguishable from zero
(the equilibrium value). We show that a large residue in Hbar is caused by a
tendency for the trajectories to be confined to sub-regions of configuration
space for some wave functions, and that this is less likely to occur for larger
numbers of energy states (if the initial phases are chosen randomly). Possible
cosmological implications are briefly discussed.


title:
A case of the deformational Hodge conjecture via a pro
  Hochschild-Kostant-Rosenberg theorem

abstract:
  Following ideas of Bloch, Esnault, and Kerz, the deformational part of
Grothendieck's variational Hodge conjecture is established for proper, smooth
schemes over $K[[t]]$, where $K$ is an algebraic extension of the rational
numbers. The main tool is a pro Hochschild-Kostant-Rosenberg theorem for
Hochschild homology.


title:
Differentiablity of excessive functions of one-dimensional diffusions
  and the principle of smooth fit

abstract:
  The principle of smooth fit is probably the most used tool to find solutions
to optimal stopping problems of one-dimensional diffusions. It is important,
e.g., in financial mathematical applications to understand in which kind of
models and problems smooth fit can fail. In this paper we connect - in case of
one-dimensional diffusions - the validity of smooth fit and the
differentiability of excessive functions. The basic tool to derive the results
is the representation theory of excessive functions; in particular, the Riesz
and Martin representations. It is seen that the differentiability may not hold
in case the speed measure of the diffusion or the representing measure of the
excessive function has atoms.
  As an example, we study optimal stopping of sticky Brownian motion. It is
known that the validity of the smooth fit in this case depends on the value of
the discounting parameter (when the other parameters are fixed). We decompose
the size of the jump in the derivative of the value function in two factors.
The first one is due to the atom of the representing measure and the second one
due to the atom of the speed measure.


title:
Radiation and magnetic field effects on new semiconductor power devices
  for HL-LHC experiments

abstract:
  The radiation hardness of commercial Silicon Carbide and Gallium Nitride
power MOSFETs is presented in this paper, for Total Ionizing Dose effects and
Single Event Effects, under gamma, neutrons, protons and heavy ions. Similar
tests are discussed for commercial DC-DC converters, also tested in operation
under magnetic field.


title: High posterior density ellipsoids of quantum states

abstract:
  Regions of quantum states generalize the classical notion of error bars. High
posterior density (HPD) credible regions are the most powerful of region
estimators. However, they are intractably hard to construct in general. This
paper reports on a numerical approximation to HPD regions for the purpose of
testing a much more computationally and conceptually convenient class of
regions: posterior covariance ellipsoids (PCEs). The PCEs are defined via the
covariance matrix of the posterior probability distribution of states. Here it
is shown that PCEs are near optimal for the example of Pauli measurements on
multiple qubits. Moreover, the algorithm is capable of producing accurate PCE
regions even when there is uncertainty in the model.


title: Theories relating baryon asymmetry and dark matter: A mini review

abstract:
  The nature of dark matter and the origin of the baryon asymmetry are two of
the deepest mysteries of modern particle physics. In the absence of hints
regarding a possible solution to these mysteries, many approaches have been
developed to tackle them simultaneously leading to very diverse and rich
models. We give a short review where we describe the general features of some
of these models and an overview on the general problem. We also propose a
diagrammatic notation to label the different models.


title:
libcloudph++ 0.2: single-moment bulk, double-moment bulk, and
  particle-based warm-rain microphysics library in C++

abstract:
  This paper introduces a library of algorithms for representing cloud
microphysics in numerical models. The library is written in C++, hence the name
libcloudph++. In the current release, the library covers three warm-rain
schemes: the single- and double-moment bulk schemes, and the particle-based
scheme with Monte-Carlo coalescence. The three schemes are intended for
modelling frameworks of different dimensionality and complexity ranging from
parcel models to multi-dimensional cloud-resolving (e.g. large-eddy)
simulations. A two-dimensional prescribed-flow framework is used in example
simulations presented in the paper with the aim of highlighting the library
features. The libcloudph++ and all its mandatory dependencies are free and
open-source software. The Boost.units library is used for zero-overhead
dimensional analysis of the code at compile time. The particle-based scheme is
implemented using the Thrust library that allows to leverage the power of
graphics processing units (GPU), retaining the possibility to compile the
unchanged code for execution on single or multiple standard processors (CPUs).
The paper includes complete description of the programming interface (API) of
the library and a performance analysis including comparison of GPU and CPU
setups.


title:
The application of the exact operational matrices for solving the
  Emden-Fowler equations, arising in astrophysics

abstract:
  The objective of this paper is to apply the well-known exact operational
matrices (EOMs) idea for solving the Emden-Fowler equations, illustrating the
superiority of EOMs versus ordinary operational matrices (OOMs). Up to now, a
few studies have been conducted on EOMs and the differential equations solved
by them do not have high-degree nonlinearity and the reported results are not
regarded as appropriate criteria for the excellence of the new method. So, we
chose Emden-Fowler type differential equations and solved them by this method.
To confirm the accuracy of the new method and to show the preeminence of EOMs
versus OOMs, the norm1 of the residual and error function of both methods are
evaluated for multiple $m$ values, where $m$ is the degree of the Bernstein
polynomials. We reported the results in form of plots to illustrate the error
convergence of both methods to zero and also to show the primacy of the new
method versus OOMs. The obtained results have demonstrated the increased
accuracy of the new method.


title: A categorification of non-crossing partitions

abstract:
  We present a categorification of the non-crossing partitions given by
crystallographic Coxeter groups. This involves a category of certain bilinear
lattices, which are essentially determined by a symmetrisable generalised
Cartan matrix together with a particular choice of a Coxeter element. Examples
arise from Grothendieck groups of hereditary artin algebras.


title: Spontaneous division and motility in active nematic droplets

abstract:
  We investigate the mechanics of an active droplet endowed with internal
nematic order and surrounded by an isotropic Newtonian fluid. Using numerical
simulations we demonstrate that, due to the interplay between the active
stresses and the defective geometry of the nematic director, this system
exhibits two of the fundamental functions of living cells: spontaneous division
and motility, by means of self-generated hydrodynamics flows. These behaviors
can be selectively activated by controlling a single physical parameter,
namely, an active variant of the capillary number.


title:
Solutions for the quasi-Yang-Baxter equation. Diagrammatics, axioms and
  semi-classical approximations

abstract:
  We generalize Nichita, Popovici and Tanasa solutions of the Braid equation to
quasi-Yang-Baxter equation. We define quasi-braided Lie algebras in an additive
monoidal category as a natural generalization of Majid's braided Lie algebra
concept. Quasi-braided Lie algebras provide solutions for the quasi-Yang-Baxter
equation. Examples came from Lie algebras in additive monoidal categories with
non-strict associativity and from the theory of quasi-triangular quasi-Hopf
algebras.


title: On the Mahler measure of the Coxeter polynomials of algebras

abstract:
  Let $A$ be a finite dimensional algebra over an algebraically closed field
$k$. Assume $A$ is a basic connected and triangular algebra with $n$ pairwise
non-isomorphic simple modules. We consider the {\em Coxeter transformation}
$\phi_A(T)$ as the automorphism of the Grothendieck group $K_0(A)$ induced by
the Auslander-Reiten translation $\tau$ in the derived category
$\Der^b(\mod_A)$ of the module category $\mod_A$ of finite dimensional left
$A$-modules. We say that $A$ is of {\em cyclotomic type} if the characteristic
polynomial $\chi_A$ of $\phi_A$ is a product of cyclotomic polynomials,
equivalently, if the {\em Mahler measure} $M(\chi_A)=1$. In \cite{Pe} we have
considered the many examples of algebras of cyclotomic type in the
representation theory literature. In this paper we study the Mahler measure of
the Coxeter polynomial of {\em accessible algebras}. In 1933, D. H. Lehmer
found that the polynomial $T^{10} + T^9 - T^7 - T^6 - T^5 - T^4 - T^3 + T + 1$
has Mahler measure $\mu_0 = 1.176280 . . .$, and he asked if there exist any
smaller values exceeding 1. In this paper we prove that for any accessible
algebra $A$ either $M(\chi_A)=1$ or $M(\chi_B) \ge \mu_0$ for some convex
subcategory $B$ of $A$. We introduce {\em interlaced tower of algebras}
$A_m,\ldots,A_n$ with $m \le n-2$ satisfying $$\chi_{A_{s+1}} =(T+1) \chi_{A_s}
- T \chi_{A_{s-1}}$$ for $m+1 \le s \le n-1$. We prove that, if ${\rm Spec
\,}\phi_{A_n} \subset \s^1 \cup \R^+$ and $A_n$ is not of cyclotomic type then
$M(\chi_{A_m}) <M(\chi_{A_n})$.


title: The 5D Standing Wave Braneworld With Real Scalar Field

abstract:
  We introduce the new 5D braneworld with the real scalar field in the bulk.
The model represents the brane which bounds collective oscillations of
gravitational and scalar field standing waves. These waves are out of phase,
i.e. the energy of oscillations passes back and forth between the scalar and
gravitational waves. When the amplitude of the standing waves is small the
brane width and the size of the horizon in extra space are of a same order of
magnitude, and matter fields are localized in extra dimension due to the
presence of the horizon. When oscillations are large trapping of matter fields
on the brane is provided mainly by the pressure of bulk waves. It is shown that
in this case the mass of the lightest KK mode is determined by the smaller
energy scale corresponding to the horizon size, i.e. these modes can be created
in accelerators at relatively low energies, which gives a chance to check the
present model.


title:
Let my people go (home) to Spain: a genealogical model of Jewish
  identities since 1492

abstract:
  The Spanish government recently announced an official fast-track path to
citizenship for any individual who is Jewish and whose ancestors were expelled
from Spain during the inquisition-related dislocation of Spanish Jews in 1492.
It would seem that this policy targets a small subset of the global Jewish
population, i.e., restricted to individuals who retain cultural practices
associated with ancestral origins in Spain. However, the central contribution
of this manuscript is to demonstrate how and why the policy is far more likely
to apply to a very large fraction (i.e., the vast majority) of Jews. This claim
is supported using a series of genealogical models that include transmissable
"identities" and preferential intra-group mating. Model analysis reveals that
even when intra-group mating is strong and even if only a small subset of a
present-day population retains cultural practices typically associated with
that of an ancestral group, it is highly likely that nearly all members of that
population have direct geneaological links to that ancestral group, given
sufficient number of generations have elapsed. The basis for this conclusion is
that not having a link to an ancestral group must be a property of all of an
individual's ancestors, the probability of which declines (nearly)
superexponentially with each successive generation. These findings highlight
unexpected incongruities induced by genealogical dynamics between present-day
and ancestral identities.


title: Discovery of GeV Emission from the Circinus galaxy with the Fermi-LAT

abstract:
  We report the discovery of gamma-ray emission from the Circinus galaxy using
the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope.
Circinus is a nearby (~4 Mpc) starburst with a heavily obscured Seyfert-type
active nucleus, bipolar radio lobes perpendicular to the spiral disk, and
kpc-scale jet-like structures. Our analysis of 0.1-100 GeV events collected
during 4 years of LAT observations reveals a significant (~ 7.3 sigma) excess
above the background. We find no indications of variability or spatial
extension beyond the LAT point-spread function. A power-law model used to
describe the 0.1-100 GeV gamma-ray spectrum yields a flux of
(18.8+/-5.8)x10^{-9} ph cm^{-2} s^{-1} and photon index 2.19+/-0.12,
corresponding to an isotropic gamma-ray luminosity of 3 x 10^{40} erg s^{-1}.
This observed gamma-ray luminosity exceeds the luminosity expected from
cosmic-ray interactions in the interstellar medium and inverse Compton
radiation from the radio lobes. Thus the origin of the GeV excess requires
further investigation.


title: Searching for transits in the WTS with difference imaging light curves

abstract:
  The Wide Field Camera Transit Survey is a pioneer program aimed to search for
extra-solar planets in the near-infrared. The standard data reduction pipeline
of the program uses aperture photometry to construct the light curves. We
alternatively apply the difference imaging method for the most complete field
in the survey and carry out a quantitative comparison between the photometric
precision of both methods for objects with J<18. We also report an
implementation on the box-fitting detection algorithm, which performs a
trapezoid-fit to the folded light curve. Subsequently a set of selection
criteria are optimized and applied to the light curves to search for transit
candidates, incorporating a parameter to characterize the shape of the transit.
We carry out a detailed analysis in the 18 best detections and classify them as
transiting planet and eclipsing binary candidates. One planet candidate
orbiting a late G-type star is reported. No planet candidate around M-stars has
been found, which enabled us to set an upper limit on the occurrence rate of
short period giant planets around M-dwarfs in the survey of 1.1%. Furthermore
we report the detection of five faint extremely-short period eclipsing binary
systems with periods shorter than 0.23 days and three candidate M-dwarf/M-dwarf
eclipsing binaries. The detections demonstrate the benefits of using the
difference imaging light curves especially when going to fainter magnitudes.


title:
Resolving Small-Scale Dark Matter Structures Using Multi-Source Indirect
  Detection

abstract:
  The extragalactic dark matter (DM) annihilation signal depends on the product
of the clumping factor, <\delta^2>, and the velocity-weighted annihilation
cross section, \sigma v. This "clumping factor-\sigma v" degeneracy can be
broken by comparing DM annihilation signals from multiple sources. In
particular, one can constrain the minimum DM halo mass, M_min, which depends on
the mass of the DM particles and the kinetic decoupling temperature, by
comparing observations of individual DM sources to the diffuse DM annihilation
signal. We demonstrate this with careful semi-analytic treatments of the DM
contribution to the diffuse Isotropic Gamma-Ray Background (IGRB), and compare
it with two recent hints of DM from the Galactic Center, namely, ~130 GeV DM
annihilating dominantly in the \chi\chi\ to \gamma\gamma\ channel, and (10-30)
GeV DM annihilating in the \chi\chi\ to b\bar{b} or \chi\chi\ to
\tau^{+}\tau^{-} channels. We show that, even in the most conservative
analysis, the Fermi IGRB measurement already provides interesting sensitivity.
A more detailed analysis of the IGRB, with new Fermi IGRB measurements and
modeling of astrophysical backgrounds, may be able to probe values of M_min up
to 1 M_sun for the 130 GeV candidate and 10^{-6} M_sun for the light DM
candidates. Increasing the substructure content of halos by a reasonable amount
would further improve these constraints.


title:
BL Lacertae identifications in a ROSAT-selected sample of Fermi
  unidentified objects

abstract:
  The optical spectroscopic followup of 27 sources belonging to a sample of 30
high-energy objects selected by positionally cross correlating the first
Fermi/LAT Catalog and the ROSAT All-Sky Survey Bright Source Catalog is
presented here. It has been found or confirmed that 25 of them are BL Lacertae
objects (BL Lacs), while the remaining two are Galactic cataclysmic variables
(CVs). This strongly suggests that the sources in the first group are
responsible for the GeV emission detected with Fermi, while the two CVs most
likely represent spurious associations. We thus find an 80% a posteriori
probability that the sources selected by matching GeV and X-ray catalogs belong
to the BL Lac class. We also show suggestions that the BL Lacs selected with
this approach are probably high-synchrotron-peaked sources and in turn good
candidates for the detection of ultra-high-energy (TeV) photons from them.


title: Dihadron Fragmentation Functions within the NJL-jet Model

abstract:
  Dihadron Fragmentation Functions (DFF) provide a vast amount of information
on the intricate details of the parton hadronization process. Moreover, they
provide a unique access to the "clean" extraction of nucleon transversity
parton distribution functions in semi inclusive deep inelastic two hadron
production process with a transversely polarised target. The NJL-jet model has
been extended for calculations of light and strange quark unpolarised DFFs to
pions, kaons and several vector mesons. This is accomplished by using the
probabilistic interpretation of the DFFs, and employing the NJL-jet
hadronization model in the Monte Carlo simulations that includes the transverse
momentum of the produced hadrons. The strong decays of the vector mesons and
the subsequent modification of the pseudoscalar meson DFFs are also considered.
The resulting pseudoscalar meson DFFs are strongly influenced by the decays of
the relevant vector mesons. This is because of the large combinatorial factors
involved in counting the number of the hadron pairs that include the decay
products. The evolution of the DFFs from the model scale to a typical
experimental scale has also been performed.


title:
The Smooth MgII gas distribution through the
  interstellar/extra-planar/halo interface

abstract:
  We report the first measurements of MgII absorption systems associated with
spectroscopically confirmed z~0.1 star-forming galaxies at projected distances
of D<6kpc. We demonstrate the data are consistent with the well known
anti-correlation between rest-frame MgII equivalent width, Wr(2796), and impact
parameter, D, represented by a single log-linear relation derived by Nielsen et
al. (MAGIICAT) that converges to ~2A at D=0kpc. Incorporating MAGIICAT, we find
that the halo gas covering fraction is unity below D~25kpc. We also report that
our D<6kpc absorbers are consistent with the Wr(2796) distributions of the
Milky Way interstellar medium (ISM) and ISM+halo. In addition, quasar
sight-lines of intermediate redshift galaxies with 6<D<25kpc have an equivalent
width distribution similar to that of the Milky Way halo, implying that beyond
~6kpc, quasar sight-lines are likely probing halo gas and not the ISM. As
inferred by the Milky Way and our new data, the gas profiles of galaxies can be
fit by a single log-linear Wr(2796)-D relation out to large scales across a
variety of gas-phase conditions and is maintained through the
halo/extra-planar/ISM interfaces, which is remarkable considering their
kinematic complexity. These low redshift, small impact parameter absorption
systems are the first steps to bridge the gap between quasar absorption-line
studies and HI observations of the CGM.


title: In the thick of it: metal-poor disc stars in RAVE

abstract:
  By selecting in the RAVE-DR4 survey the stars located between 1 and 2 kpc
above the Galactic plane, we question the consistency of the simplest
three-component model (thin disc, thick disc, halo) for the Milky Way. We
confirm that the metallicity and azimuthal velocity distribution functions of
the thick disc are not Gaussian. In particular, we find that the thick disc has
an extended metallicity tail going at least down to [M/H]=-2 dex, contributing
roughly at 3% of the entire thick disc population and having a shorter
scale-length compared to the canonical thick disc. The mean azimuthal velocity
of these metal-poor stars allows us to estimate the correlation between the
metallicity and the orbital velocity, which is an important constraint on the
formation mechanisms of the Galactic thick disc. Given our simple approach, we
find dVphi/d[M/H] ~ 50 km/s/dex, which is in a very good agreement with
previous literature values. We complete the study with a brief discussion on
the implications of the formation scenarios for the thick disc, and suggest
that given the above mentioned characteristics, a thick disc mainly formed by
radial migration mechanisms seems unlikely.


title:
Where the world stands still: turnaround as a strong test of \Lambda CDM
  cosmology

abstract:
  Our intuitive understanding of cosmic structure formation works best in
scales small enough so that bound, relaxed gravitating systems are no longer
adjusting their radius; and large enough so that space and matter follow the
average expansion of the Universe. Yet one of the most robust predictions of
$\Lambda$CDM cosmology concerns the scale that separates these limits: the
turnaround radius, which is the non-expanding shell furthest away from the
center of a bound structure. The maximum possible value of the turnaround
radius within the framework of the $\Lambda$CDM model is, for a given mass $M$,
equal to $(3GM/\Lambda c^2)^{1/3}$, with $G$ Newton's constant and $c$ the
speed of light, independently of cosmic epoch, exact nature of dark matter, or
baryonic effects. We discuss the possible use of this prediction as an
observational test for $\Lambda$CDM cosmology.


title: FeynRules 2.0 - A complete toolbox for tree-level phenomenology

abstract:
  FeynRules is a Mathematica-based package which addresses the implementation
of particle physics models, which are given in the form of a list of fields,
parameters and a Lagrangian, into high-energy physics tools. It calculates the
underlying Feynman rules and outputs them to a form appropriate for various
programs such as CalcHEP, FeynArts, MadGraph, Sherpa and Whizard. Since the
original version, many new features have been added: support for two-component
fermions, spin-3/2 and spin-2 fields, superspace notation and calculations,
automatic mass diagonalization, completely general FeynArts output, a new
universal FeynRules output interface, a new Whizard interface, automatic 1 to 2
decay width calculation, improved speed and efficiency, new guidelines for
validation and a new web-based validation package. With this feature set,
FeynRules enables models to go from theory to simulation and comparison with
experiment quickly, efficiently and accurately.


title: The Mean Star-Forming Properties of QSO Host Galaxies

abstract:
  Quasi-stellar objects (QSOs) occur in galaxies in which supermassive black
holes (SMBHs) are growing substantially through rapid accretion of gas. Many
popular models of the co-evolutionary growth of galaxies and SMBHs predict that
QSOs are also sites of substantial recent star formation, mediated by important
processes, such as major mergers, which rapidly transform the nature of
galaxies. A detailed study of the star-forming properties of QSOs is a critical
test of such models. We present a far-infrared Herschel/PACS study of the mean
star formation rate (SFR) of a sample of spectroscopically observed QSOs to z~2
from the COSMOS extragalactic survey. This is the largest sample to date of
moderately luminous AGNs studied using uniform, deep far-infrared photometry.
We study trends of the mean SFR with redshift, black hole mass, nuclear
bolometric luminosity and specific accretion rate (Eddington ratio). To
minimize systematics, we have undertaken a uniform determination of SMBH
properties, as well as an analysis of important selection effects within
spectroscopic QSO samples that influence the interpretation of SFR trends. We
find that the mean SFRs of these QSOs are consistent with those of normal
massive star-forming galaxies with a fixed scaling between SMBH and galaxy mass
at all redshifts. No strong enhancement in SFR is found even among the most
rapidly accreting systems, at odds with several co-evolutionary models.
Finally, we consider the qualitative effects on mean SFR trends from different
assumptions about the star-forming properties of QSO hosts and redshift
evolution of the SMBH-galaxy relationship. While limited currently by
uncertainties, valuable constraints on AGN-galaxy co-evolution can emerge from
our approach.


title: Delayed star formation in high-redshift stream-fed galaxies

abstract:
  We propose that star formation is delayed relative to the inflow rate in
rapidly-accreting galaxies at very high redshift (z > 2) because of the energy
conveyed by the accreting gas. Accreting gas streams provide fuel for star
formation, but they stir the disk and increase turbulence above the usual
levels compatible with gravitational instability, reducing the star formation
efficiency in the available gas. After the specific inflow rate has
sufficiently decreased - typically at z < 3 - galaxies settle in a
self-regulated regime with efficient star formation. An analytic model shows
that this interaction between infalling gas and young galaxies can
significantly delay star formation and maintain high gas fractions (>40%) down
to z = 2, in contrast to other galaxy formation models. Idealized hydrodynamic
simulations of infalling gas streams onto primordial galaxies confirm the
efficient energetic coupling at z > 2, and suggest that this effect is largely
under-resolved in existing cosmological simulations.


title: New insights into the dust formation of oxygen-rich AGB stars

abstract:
  We observed the AGB stars S Ori, GX Mon and R Cnc with the MIDI instrument at
the VLTI. We compared the data to radiative transfer models of the dust shells,
where the central stellar intensity profiles were described by dust-free
dynamic model atmospheres. We used Al2O3 and warm silicate grains. Our S Ori
and R Cnc data could be well described by an Al2O3 dust shell alone, and our GX
Mon data by a mix of an Al2O3 and a silicate shell. The best-fit parameters for
S Ori and R Cnc included photospheric angular diameters Theta(Phot) of
9.7+/-1.0mas and 12.3+/-1.0mas, optical depths tau(V)(Al2O3) of 1.5+/-0.5 and
1.35+/-0.2, and inner radii R(in) of 1.9+/-0.3R(Phot) and 2.2+/-0.3R(Phot),
respectively. Best-fit parameters for GX Mon were Theta(Phot)=8.7+/-1.3mas,
tau(V)(Al2O3)=1.9+/-0.6, R(in)(Al2O3)=2.1+/-0.3R(Phot),
tau(V)(silicate)=3.2+/-0.5, and R(in)(silicate)=4.6+/-0.2R(Phot). Our model
fits constrain the chemical composition and the inner boundary radii of the
dust shells, as well as the photospheric angular diameters. Our interferometric
results are consistent with Al2O3 grains condensing close to the stellar
surface at about 2 stellar radii, co-located with the extended atmosphere and
SiO maser emission, and warm silicate grains at larger distances of about 4--5
stellar radii. We verified that the number densities of aluminum can match that
of the best-fit Al2O3 dust shell near the inner dust radius in sufficiently
extended atmospheres, confirming that Al2O3 grains can be seed particles for
the further dust condensation. Together with literature data of the mass-loss
rates, our sample is consistent with a hypothesis that stars with low mass-loss
rates form primarily dust that preserves the spectral properties of Al2O3, and
stars with higher mass-loss rate form dust with properties of warm silicates.