title: A note on torsion length

abstract:
  We construct a 2-generator recursively presented group with infinite torsion
length. We also explore the construction in the context of solvable and
word-hyperbolic groups.


title: Local epsilon isomorphisms

abstract:
  In this paper, we prove the "local epsilon-isomorphism conjecture" of Fukaya
and Kato for a particular class of Galois modules obtained by tensoring a
Zp-lattice in a crystalline representation of the Galois group of Qp with a
representation of an abelian quotient of the Galois group with values in a
suitable p-adic local ring. This can be regarded as a local analogue of the
Iwasawa main conjecture for abelian p-adic Lie extensions of Qp, extending
earlier work of Benois and Berger for the cyclotomic extension. We show that
such an epsilon-isomorphism can be constructed using the Perrin-Riou regulator
map, or its extension to the 2-variable case due to the first and third
authors.


title: Meta-Kernelization with Structural Parameters

abstract:
  Meta-kernelization theorems are general results that provide polynomial
kernels for large classes of parameterized problems. The known
meta-kernelization theorems, in particular the results of Bodlaender et al.
(FOCS'09) and of Fomin et al. (FOCS'10), apply to optimization problems
parameterized by solution size. We present the first meta-kernelization
theorems that use a structural parameters of the input and not the solution
size. Let C be a graph class. We define the C-cover number of a graph to be a
the smallest number of modules the vertex set can be partitioned into, such
that each module induces a subgraph that belongs to the class C. We show that
each graph problem that can be expressed in Monadic Second Order (MSO) logic
has a polynomial kernel with a linear number of vertices when parameterized by
the C-cover number for any fixed class C of bounded rank-width (or
equivalently, of bounded clique-width, or bounded Boolean width). Many graph
problems such as Independent Dominating Set, c-Coloring, and c-Domatic Number
are covered by this meta-kernelization result. Our second result applies to MSO
expressible optimization problems, such as Minimum Vertex Cover, Minimum
Dominating Set, and Maximum Clique. We show that these problems admit a
polynomial annotated kernel with a linear number of vertices.


title:
Crystal-symmetry preserving Wannier states for fractional chern
  insulators

abstract:
  Recently, many numerical evidences of fractional Chern insulator, i.e. the
fractional quantum Hall states on lattices, are proposed when a Chern band is
partially filled. Some trial wavefunctions of fractional Chern insulators can
be obtained by mapping the fractional quantum Hall wavefunctions defined in the
continuum onto the lattice through the Wannier state representation (Phys. Rev.
Lett. 107, 126803 (2011)) in which the single particle Landau orbits in the
Landau levels are identified with the one dimensional Wannier states of the
Chern bands with Chern number C = 1. However, this mapping generically breaks
the lattice point group symmetry. In this paper, we discuss a general approach
of modifying the mapping to accommodate the lattice rotational symmetry. The
wavefunctions constructed through this modified mapping should serve as better
trial wavefunctions to compare with the numerics and also as the basis for
construction of lattice symmetry preserving pseudo-potential formalism for
fractional Chern insulators. The focus of this paper shall be mainly on the
$C_4$ rotational symmetry of square lattices. Similar analysis can be
straightforwardly generalized to triangular or hexagonal lattices with $C_6$
symmetry. We also generalize the discussion to the lattice symmetry of
fractional Chern insulators with high Chern number bands.


title: Poly-Omic Prediction of Complex Traits: OmicKriging

abstract:
  High-confidence prediction of complex traits such as disease risk or drug
response is an ultimate goal of personalized medicine. Although genome-wide
association studies have discovered thousands of well-replicated polymorphisms
associated with a broad spectrum of complex traits, the combined predictive
power of these associations for any given trait is generally too low to be of
clinical relevance. We propose a novel systems approach to complex trait
prediction, which leverages and integrates similarity in genetic,
transcriptomic or other omics-level data. We translate the omic similarity into
phenotypic similarity using a method called Kriging, commonly used in
geostatistics and machine learning. Our method called OmicKriging emphasizes
the use of a wide variety of systems-level data, such as those increasingly
made available by comprehensive surveys of the genome, transcriptome and
epigenome, for complex trait prediction. Furthermore, our OmicKriging framework
allows easy integration of prior information on the function of subsets of
omics-level data from heterogeneous sources without the sometimes heavy
computational burden of Bayesian approaches. Using seven disease datasets from
the Wellcome Trust Case Control Consortium (WTCCC), we show that OmicKriging
allows simple integration of sparse and highly polygenic components yielding
comparable performance at a fraction of the computing time of a recently
published Bayesian sparse linear mixed model method. Using a cellular growth
phenotype, we show that integrating mRNA and microRNA expression data
substantially increases performance over either dataset alone. We also
integrate genotype and expression data to predict change in LDL cholesterol
levels after statin treatment and show that OmicKriging performs better than
the polygenic score method. We provide an R package to implement OmicKriging.


title: Problem with critical Sobolev exponent and with weight

abstract:
  We study existence results for a problem with criticical Sobolev exponent and
with a positive weight.


title: Control of Underwater Vehicles in Inviscid Fluids. I: Irrotational Flows

abstract:
  In this paper, we investigate the controllability of an underwater vehicle
immersed in an infinite volume of an inviscid fluid whose flow is assumed to be
irrotational. Taking as control input the flow of the fluid through a part of
the boundary of the rigid body, we obtain a finite-dimensional system similar
to Kirchhoff laws in which the control input appears through both linear terms
(with time derivative) and bilinear terms. Applying Coron's return method, we
establish some local controllability results for the position and velocities of
the underwater vehicle. Examples with six, four, or only three controls inputs
are given for a vehicule with an ellipsoidal shape.


title: Carbon-enhanced metal-poor stars: the most pristine objects?

abstract:
  Carbon-enhanced metal poor stars (CEMP) form a significant proportion of the
metal-poor stars, their origin is not well understood. Three very metal-poor
C-rich turnoff stars were selected from the SDSS survey, observed with the ESO
VLT (UVES) to precisely determine the element abundances. In turnoff stars
(unlike giants) the carbon abundance has not been affected by mixing with deep
layers and is therefore easier to interpret. The analysis was performed with 1D
LTE static model atmospheres. When available, non-LTE corrections were applied
to the classical LTE abundances. The 3D effects on the CH and CN molecular
bands were computed using hydrodynamical simulations of the stellar atmosphere
(CO5BOLD) and are found to be very important. To facilitate a comparison with
previous results, only 1D abundances are used in the discussion. The abundances
(or upper limits) of the elements enable us to place these stars in different
CEMP classes. The carbon abundances confirm the existence of a plateau at A(C)=
8.25 for [Fe/H] \geq -3.4. The most metal-poor stars ([Fe/H] < -3.4) have
significantly lower carbon abundances, suggesting a lower plateau at A(C)
\approx 6.5. Detailed analyses of a larger sample of very low metallicity
carbon-rich stars are required to confirm (or refute) this possible second
plateau and specify the behavior of the CEMP stars at very low metallicity.


title: Experimental Adaptive Bayesian Tomography

abstract:
  We report an experimental realization of an adaptive quantum state tomography
protocol. Our method takes advantage of a Bayesian approach to statistical
inference and is naturally tailored for adaptive strategies. For pure states we
observe close to 1/N scaling of infidelity with overall number of registered
events, while best non-adaptive protocols allow for $1/\sqrt{N}$ scaling only.
Experiments are performed for polarization qubits, but the approach is readily
adapted to any dimension.


title: Pathways to faceting of vesicles

abstract:
  The interplay between geometry, topology and order can lead to geometric
frustration that profoundly affects the shape and structure of a curved
surface. In this commentary we show how frustration in this context can result
in the faceting of elastic vesicles. We show that, under the right conditions,
an assortment of regular and irregular polyhedral structures may be the low
energy states of elastic membranes with spherical topology. In particular, we
show how topological defects, necessarily present in any crystalline lattice
confined to spherical topology, naturally lead to the formation of icosahedra
in a homogeneous elastic vesicle. Furthermore, we show that introducing
heterogeneities in the elastic properties, or allowing for non-linear bending
response of a homogeneous system, opens non-trivial pathways to the formation
of faceted, yet non-icosahedral, structures.


title:
Quadrupole Anisotropy in Dihadron Azimuthal Correlations in Central
  $d$$+$Au Collisions at $\sqrt{s_{_{NN}}}$=200 GeV

abstract:
  The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC)
reports measurements of azimuthal dihadron correlations near midrapidity in
$d$$+$Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV. These measurements
complement recent analyses by experiments at the Large Hadron Collider (LHC)
involving central $p$$+$Pb collisions at $\sqrt{s_{_{NN}}}$=5.02 TeV, which
have indicated strong anisotropic long-range correlations in angular
distributions of hadron pairs. The origin of these anisotropies is currently
unknown. Various competing explanations include parton saturation and
hydrodynamic flow. We observe qualitatively similar, but larger, anisotropies
in $d$$+$Au collisions compared to those seen in $p$$+$Pb collisions at the
LHC. The larger extracted $v_2$ values in $d$$+$Au collisions at RHIC are
consistent with expectations from hydrodynamic calculations owing to the larger
expected initial-state eccentricity compared with that from $p$$+$Pb
collisions. When both are divided by an estimate of the initial-state
eccentricity the scaled anisotropies follow a common trend with multiplicity
that may extend to heavy ion data at RHIC and the LHC, where the anisotropies
are widely thought to arise from hydrodynamic flow.


title:
Rate Gain Region and Design Tradeoffs for Full-Duplex Wireless
  Communications

abstract:
  In this paper, we analytically study the regime in which practical
full-duplex systems can achieve larger rates than an equivalent half-duplex
systems. The key challenge in practical full-duplex systems is uncancelled
self-interference signal, which is caused by a combination of hardware and
implementation imperfections. Thus, we first present a signal model which
captures the effect of significant impairments such as oscillator phase noise,
low-noise amplifier noise figure, mixer noise, and analog-to-digital converter
quantization noise. Using the detailed signal model, we study the rate gain
region, which is defined as the region of received signal-of-interest strength
where full-duplex systems outperform half-duplex systems in terms of achievable
rate. The rate gain region is derived as a piece-wise linear approximation in
log-domain, and numerical results show that the approximation closely matches
the exact region. Our analysis shows that when phase noise dominates mixer and
quantization noise, full-duplex systems can use either active analog
cancellation or base-band digital cancellation to achieve near-identical rate
gain regions. Finally, as a design example, we numerically investigate the
full-duplex system performance and rate gain region in typical indoor
environments for practical wireless applications.


title:
The orbit of the Chelyabinsk event impactor as reconstructed from
  amateur and public footage

abstract:
  A ballistic reconstruction of a meteoroid orbit can be made if enough
information is available about its trajectory inside the atmosphere. A few
methods have been devised in the past and used in several cases to trace back
the origin of small impactors. On February 15, 2013, a medium-sized meteoroid
hit the atmosphere in the Chelyabinsk region of Russia, causing damage in
several large cities. The incident, the largest registered since the Tunguska
event, was witnessed by many thousands and recorded by hundreds of amateur and
public video recording systems. The amount and quality of the information
gathered by those systems is sufficient to attempt a reconstruction of the
trajectory of the impactor body in the atmosphere, and from this the orbit of
the body with respect to the Sun. Using amateur and public footage taken in
four different places close to the event, we have determined precisely the
properties of the entrance trajectory and the orbit of the Chelyabinsk event
impactor. We found that the object entered the atmosphere at a velocity ranging
from 16.0 to 17.4 km/s in a grazing trajectory, almost directly from the east,
with an azimuth of velocity vector of 285$^o$, and with an elevation of
15.8$^o$ with respect to the local horizon. The orbit that best fits the
observations has, at a 95% confidence level, a semi-major axis a =
1.26$\pm$0.05 AU, eccentricity e = 0.44$\pm$0.03, argument of perihelion
$\omega$=95.5$^o\pm2^o$ and longitude of ascending node $\Omega$=
326.5$^o\pm0.3^o$. Using these properties the object can be classified as
belonging to the Apollo family of asteroids. The absolute magnitude of the
meteoroid was H= 25.8, well below the threshold for its detection and
identification as a Potential Hazardous Asteroid (PHA). This result would imply
that present efforts intended to detect and characterize PHAs are incomplete.


title: Edge of Chaos and Genesis of Turbulence

abstract:
  The edge of chaos is analyzed in a spatially extended system, modeled by the
regularized long-wave equation, prior to the transition to permanent
spatiotemporal chaos. In the presence of coexisting attractors, a chaotic
saddle is born at the basin boundary due to a smooth-fractal metamorphosis. As
a control parameter is varied, the chaotic transient evolves to well-developed
transient turbulence via a cascade of fractal-fractal metamorphoses. The edge
state responsible for the edge of chaos and the genesis of turbulence is an
unstable travelling wave in the laboratory frame, corresponding to a saddle
point lying at the basin boundary in the Fourier space.


title: Gamma-ray lines in the Fermi-LAT data?

abstract:
  Gamma-ray lines are traditional smoking gun signatures for dark matter
annihilation in the Universe. In regions optimized for large signal-to-noise
ratio, we identified a signal candidate for a gamma-ray line at energies around
130 GeV with a post-trials significance of 3.2\sigma. Spectral and spatial
properties are not inconsistent with a dark matter signal. One year has passed
since the initial papers, and I give here a brief summary and an update on the
status of the 130 GeV feature in the un-reprocessed P7 gamma-ray data of the
Fermi-LAT.


title:
Holder continuity for the ring $Q$-homeomorphisms with respect to
  $p$-modulus

abstract:
  It is founded the sufficient condition of Holder continuity of the ring
$Q$-homeomorphisms in $\mathbb{R}^n, n\geq 2$ with respect to $p$-modulus at
$n-1<p<n$.


title: Mapping Image Potential States on Graphene Quantum Dots

abstract:
  Free electron like image potential states are observed in scanning tunneling
spectroscopy on graphene quantum dots on Ir(111) acting as potential wells. The
spectrum strongly depends on the size of the nanostructure as well as on the
spatial position on top, indicating lateral confinement. Analysis of the
substructure of the first state by spatial mapping of constant energy local
density of states reveals characteristic patterns of confined states. The most
pronounced state is not the ground state, but an excited state with a favorable
combination of local density of states and parallel momentum transfer in the
tunneling process. Chemical gating tunes the confining potential by changing
the local workfunction. Our experimental determination of this workfunction
allows to deduce the associated shift of the Dirac point.


title: The rigidity of some finite group actions on CAT($\kappa$) spaces

abstract:
  In this paper, we first prove the optimal lower bound for Alexandrov angle
rigidity of torsion elliptic isometries on any complete CAT($\kappa$) space,
which, when attained, leads to an embedded 2-flat in the tangent cone invariant
under the induced action of the isometry. Next, we will prove similar result
for action of symmetry groups of either a regular orthoplex, a regular
hypercube, a regular dodecahedron or a regular icosahedron on a set of points
in any complete CAT($\kappa$) space in a way corresponds to the set of vertices
of the polytope, the angle made at the circumcenter by any pair of points
corresponding to an edge is bounded below by that of the edge in the polytope.
As a result, we give a condition for the convex hull of the set of points to be
isometric to a corresponding regular polytope in a model space of constant
curvature $\kappa$.


title: Mirror-field-atom interaction: Hamiltonian diagonalization

abstract:
  We show that the interaction between a movable mirror with a quantized field
that interacts with a two-level atom may be simplified via a transformation
that involves Susskind-Glogower operators (SGO). By using this transformation
it is easy to show that we can cast the Hamiltonian, after a series of small
rotations, into an effective Hamiltonian that may be solved. We would like to
stress that the transformation in terms of SGO already simplifies enough the
Hamiltonian in the sense that, in an exact way, it "eliminates" one of the
three-subsystems, namely the quantized field.


title:
Classifying gauge anomalies through SPT orders and classifying
  gravitational anomalies through topological orders

abstract:
  In this paper, we systematically study gauge anomalies in bosonic and
fermionic weak-coupling gauge theories with gauge group G (which can be
continuous or discrete). We show a very close relation between gauge anomalies
and symmetry-protected trivial (SPT) orders [also known as symmetry-protected
topological (SPT) orders] in one-higher dimensions. Using such an idea, we
argue that, in d space-time dimensions, the gauge anomalies are described by
the elements in Free[H^{d+1}(G,R/Z)]\oplus H_\pi^{d+1}(BG,R/Z). The well known
Adler-Bell-Jackiw anomalies are classified by the free part of the group
cohomology class H^{d+1}(G,R/Z) of the gauge group G (denoted as
Free[H^{d+1}(G,\R/\Z)]). We refer other kinds of gauge anomalies beyond
Adler-Bell-Jackiw anomalies as nonABJ gauge anomalies, which include Witten
SU(2) global gauge anomaly. We introduce a notion of \pi-cohomology group,
H_\pi^{d+1}(BG,R/Z), for the classifying space BG, which is an Abelian group
and include Tor[H^{d+1}(G,R/Z)] and topological cohomology group
H^{d+1}(BG,R/Z) as subgroups. We argue that H_\pi^{d+1}(BG,R/Z) classifies the
bosonic nonABJ gauge anomalies, and partially classifies fermionic nonABJ
anomalies. Using the same approach that shows gauge anomalies to be connected
to SPT phases, we can also show that gravitational anomalies are connected to
topological orders (ie patterns of long-range entanglement) in one-higher
dimension.


title:
The complement of the closed unit ball in $\mathbb C^3$ is not
  subelliptic

abstract:
  In this short note we show that $\mathbb C^n\setminus\bar{\mathbb B^n}$ is
not subelliptic for $n \geq 3$. This is done by proving a Hartogs type
extension theorem for holomorphic vector bundles bundles.


title: Representation zeta functions of self-similar branched groups

abstract:
  We compute the number of irreducible linear representations of self-similar
branch groups, by expressing these numbers as the co\"efficients a_n of a
Dirichlet series sum a_n n^{-s}.
  We show that this Dirichlet series has a positive abscissa of convergence, is
algebraic over the ring Q[2^{-s},...,P^{-s}] for some integer P, and show that
it can be analytically continued (through root singularities) to the left
half-plane.
  We compute the abscissa of convergence and the functional equation for some
prominent examples of branch groups, such as the Grigorchuk and Gupta-Sidki
groups.


title: CFHTLenS: Mapping the Large Scale Structure with Gravitational Lensing

abstract:
  We present a quantitative analysis of the largest contiguous maps of
projected mass density obtained from gravitational lensing shear. We use data
from the 154 deg2 covered by the Canada-France-Hawaii Telescope Lensing Survey.
Our study is the first attempt to quantitatively characterize the scientific
value of lensing maps, which could serve in the future as a complementary
approach to the study of the dark universe with gravitational lensing. We show
that mass maps contain unique cosmological information beyond that of
traditional two-points statistical analysis techniques. Using a series of
numerical simulations, we first show how, reproducing the CFHTLenS observing
conditions, gravitational lensing inversion provides a reliable estimate of the
projected matter distribution of large scale structure. We validate our
analysis by quantifying the robustness of the maps with various statistical
estimators. We then apply the same process to the CFHTLenS data. We find that
the 2-points correlation function of the projected mass is consistent with the
cosmological analysis performed on the shear correlation function discussed in
the CFHTLenS companion papers. The maps also lead to a significant measurement
of the third order moment of the projected mass, which is in agreement with
analytic predictions, and to a marginal detection of the fourth order moment.
Tests for residual systematics are found to be consistent with zero for the
statistical estimators we used. A new approach for the comparison of the
reconstructed mass map to that predicted from the galaxy distribution reveals
the existence of giant voids in the dark matter maps as large as 3 degrees on
the sky. Our analysis shows that lensing mass maps can be used for new
techniques such as peak statistics and the morphological analysis of the
projected dark matter distribution.


title: On Integrating the Left-Flat Vacuum Einstein Equations

abstract:
  Considering the spin-coefficient version of the left-flat vacuum Einstein
equations, all but one of the fifty equations can be explicitly integrated via
the introduction of five spin-weight s=-2 complex potentials. The final
equation is a non-linear wave equation for the last of the potentials.
Solutions to this equation determine solutions for the entire system. Solutions
for several special cases are obtained


title:
CFHTLenS tomographic weak lensing cosmological parameter constraints:
  Mitigating the impact of intrinsic galaxy alignments

abstract:
  We present a finely-binned tomographic weak lensing analysis of the
Canada-France-Hawaii Telescope Lensing Survey, CFHTLenS, mitigating
contamination to the signal from the presence of intrinsic galaxy alignments
via the simultaneous fit of a cosmological model and an intrinsic alignment
model. CFHTLenS spans 154 square degrees in five optical bands, with accurate
shear and photometric redshifts for a galaxy sample with a median redshift of
zm =0.70. We estimate the 21 sets of cosmic shear correlation functions
associated with six redshift bins, each spanning the angular range of
1.5<theta<35 arcmin. We combine this CFHTLenS data with auxiliary cosmological
probes: the cosmic microwave background with data from WMAP7, baryon acoustic
oscillations with data from BOSS, and a prior on the Hubble constant from the
HST distance ladder. This leads to constraints on the normalisation of the
matter power spectrum sigma_8 = 0.799 +/- 0.015 and the matter density
parameter Omega_m = 0.271 +/- 0.010 for a flat Lambda CDM cosmology. For a flat
wCDM cosmology we constrain the dark energy equation of state parameter w =
-1.02 +/- 0.09. We also provide constraints for curved Lambda CDM and wCDM
cosmologies. We find the intrinsic alignment contamination to be galaxy-type
dependent with a significant intrinsic alignment signal found for early-type
galaxies, in contrast to the late-type galaxy sample for which the intrinsic
alignment signal is found to be consistent with zero.


title: Insane Anti-Membranes?

abstract:
  The backreactions of anti-branes on a variety of supergravity backgrounds
have been shown in a recent series of papers to be riled by some unexplained
flux singularities. All of the situations studied so far involve backgrounds
with (close to) AdS-asymptotics. It is the purpose of this work to study the
backreaction of anti-M2 branes on a background exhibiting a different UV
behavior: The so-called $\mathbb{A}_8$ regular solution of eleven-dimensional
supergravity that we consider has "Taub-NUT type" asymptotics. As it turns out,
some subleading infrared singularities are inevitable; they cannot be naturally
ascribed to the anti-branes backreacting on this background. Moreover, our
configuration does not involve smeared branes. This lends further credence to
the work of Bena et al. suggesting that the singularities encountered are in no
way remnants of smearing that would wash away once brane polarization is taken
into account.


title: Free dense subgroups of holomorphic automorphisms

abstract:
  We show the existence of free dense subgroups, generated by 2 elements, in
the holomorphic shear and overshear group of complex-Euklidean space and extend
this result to the group of holomorphic automorphisms of Stein manifolds with
Density Property, provided there exists a generalized translation. The
conjugation operator associated to this generalized translation is hypercyclic
on the topological space of holomorphic automorphisms.


title: Little flavor: A model of weak-scale flavor physics

abstract:
  We describe a model of quarks which identifies the large global symmetries of
little Higgs models with the global flavor symmetries that arise in a
deconstruction of the extra-dimensional 'topological insulator' model of
flavor. The nonlinearly realized symmetries of little Higgs theories play a
critical role in determining the flavor structure of fermion masses and mixing.
All flavor physics occurs at the few TeV scale in this model, yet flavor
changing neutral currents arising from the new physics are naturally smaller
than those generated radiatively in the standard model, without having to
invoke minimal flavor violation.


title: Higgs At Last

abstract:
  We update the experimental constraints on the parameters of the Higgs
effective Lagrangian. We combine the most recent LHC Higgs data in all
available search channels with electroweak precision observables from SLC,
LEP-1, LEP-2, and the Tevatron. Overall, the data are perfectly consistent with
the 126 GeV particle being the Standard Model Higgs boson. The Higgs coupling
to W and Z bosons relative to the Standard Model one is constrained in the
range [0.98,1.09] at 95% confidence level, independently of the values of other
Higgs couplings. Higher-order Higgs couplings to electroweak gauge bosons are
also well constrained by a combination of LHC Higgs data and electroweak
precision tests.


title:
The strange close binary V405 And: the influence of different dynamos on
  the components

abstract:
  V405 And is a fast-rotating (P=0.465d) grazing eclipsing binary with two
active components. Using multicolor photometric monitoring and radial velocity
measurements, we find that the primary and the secondary components have masses
of 0.49 and 0.21 solar masses, meaning that the primary probably possesses a
radiative core and a convective envelope, while the secondary is fully
convective. The radius of the low-mass component fits well the theoretical
mass-radius relation. However, the radius of the primary is significantly
larger than the predicted value, in fact, the discrepancy is far the highest
from the four similar objects known.


title:
Slipher's redshifts as support for de Sitter's model and the discovery
  of the dynamic universe

abstract:
  Of the first two relativistiv world models, only the one by de Sitter
predicted redshifted spectra from far away astronomical objects. Slipher's
redshifts therefore seemed to arbitrate against Einstein's model which made no
such predictions. Both models were trying to describe a static universe.
However, Lemaitre found that de Sitter's construct resulted in a spatially
inhomogeneous universe. He then opted for a model that correspondes to
Einstein's closed, curved universe but allowed the radius of curvature to
change with time. Slipher's redshifts suggested to him that the universe is
dynamic and expanding. We also discuss the respective merits of Friedman and
Lemaitre in revealing the dynamic nature of the universe.


title:
About $K^o, \bar K^o$ meson oscillations at strangeness violation by
  weak interactions without and with taking into account meson decays

abstract:
  This work considers $K^0, \bar K^0$ meson mixings and oscillations via
$K^0_1, K^0_2$ meson states at strangeness violation by weak interactions in
two cases - without and with taking into account $K^0_1, K^0_2$ meson decays.
In the first case the oscillation theory correctly describes $K^o, \bar K^o \to
K^o, \bar K^o$ transition processes. In the second case, when we take into
account meson decays, the oscillation theory cannot correctly describe this
process at long distances since mainly $K^o_2$ mesons remain at long distances
therefore the condition for oscillations is absent. So, at long distances in
this process only long living $K^0_2$ mesons are present but not $K^o, \bar
K^o$ mesons.


title:
Self-energy anomaly of an electric pointlike dipole in three-dimensional
  static spacetimes

abstract:
  We calculate the self-energy anomaly of a pointlike electric dipole located
in a static $(2+1)$-dimensional curved spacetime. The energy functional for
this problem is invariant under an infinite-dimensional (gauge) group of
transformations parameterized by one scalar function of two variables. We
demonstrate that the problem of the calculation of the self-energy anomaly for
a pointlike dipole can be reduced to the calculation of quantum fluctuations of
an effective two-dimensional Euclidean quantum field theory. We reduced the
problem in question to the calculation of the conformal anomaly of an effective
scalar field in two dimensions and obtained an explicit expression for the
self-energy anomaly of an electric dipole in an asymptotically flat, regular
$(2+1)$-dimensional spacetime which may have electrically neutral
black-hole-like metrics with regular Killing horizon.


title:
The vast thin plane of M31 co-rotating dwarfs: an additional fossil
  signature of the M31 merger and of its considerable impact in the whole Local
  Group

abstract:
  The recent discovery by Ibata et al. (2013) of a vast thin disk of satellites
(VTDS) around M31 offers a new challenge for the understanding of the Local
Group properties. This comes in addition to the unexpected proximity of the
Magellanic Clouds (MCs) to the Milky Way (MW), and to another vast polar
structure (VPOS), which is almost perpendicular to our Galaxy disk. We find
that the VTDS plane is coinciding with several stellar, tidally-induced streams
in the outskirts of M31, and, that its velocity distribution is consistent with
that of the Giant Stream (GS). This is suggestive of a common physical
mechanism, likely linked to merger tidal interactions, knowing that a similar
argument may apply to the VPOS at the MW location. Furthermore, the VTDS is
pointing towards the MW, being almost perpendicular to the MW disk, as the VPOS
is.
  We compare these properties to the modelling of M31 as an ancient, gas-rich
major merger, which has been successfully used to predict the M31 substructures
and the GS origin. We find that without fine tuning, the induced tidal tails
are lying in the VTDS plane, providing a single and common origin for many
stellar streams and for the vast stellar structures surrounding both the MW and
M31. The model also reproduces quite accurately positions and velocities of the
VTDS dSphs. Our conjecture leads to a novel interpretation of the Local Group
past history, as a gigantic tidal tail due to the M31 ancient merger is
expected to send material towards the MW, including the MCs. Such a link
between M31 and the MW is expected to be quite exceptional, though it may be in
qualitative agreement with the reported rareness of MW-MCs systems in nearby
galaxies.


title:
PS1-12sk is a Peculiar Supernova From a He-rich Progenitor System in a
  Brightest Cluster Galaxy Environment

abstract:
  We report on our discovery and observations of the Pan-STARRS1 supernova (SN)
PS1-12sk, a transient with properties that indicate atypical star formation in
its host galaxy cluster or pose a challenge to popular progenitor system models
for this class of explosion. The optical spectra of PS1-12sk classify it as a
Type Ibn SN (c.f. SN 2006jc), dominated by intermediate-width (3x10^3 km/s) and
time variable He I emission. Our multi-wavelength monitoring establishes the
rise time dt = 9-23 days and shows an NUV-NIR SED with temperature > 17x10^3 K
and a peak rise magnitude of Mz = -18.9 mag. SN Ibn spectroscopic properties
are commonly interpreted as the signature of a massive star (17 - 100 M_sun)
explosion within a He-enriched circumstellar medium. However, unlike previous
Type Ibn supernovae, PS1-12sk is associated with an elliptical brightest
cluster galaxy, CGCG 208-042 (z = 0.054) in cluster RXC J0844.9+4258. The
expected probability of an event like PS1-12sk in such environments is low
given the measured infrequency of core-collapse SNe in red sequence galaxies
compounded by the low volumetric rate of SN Ibn. Furthermore, we find no
evidence of star formation at the explosion site to sensitive limits (Sigma
Halpha < 2x10^-3 M_sun/yr/kpc^2). We therefore discuss white dwarf binary
systems as a possible progenitor channel for SNe Ibn. We conclude that PS1-12sk
represents either a fortuitous and statistically unlikely discovery, evidence
for a top-heavy IMF in galaxy cluster cooling flow filaments, or the first clue
suggesting an alternate progenitor channel for Type Ibn SNe.


title: The X-ray Properties of Optically Selected Clusters of Galaxies

abstract:
  We present the results of Chandra and Suzaku X-ray observations of nine
moderate-redshift (0.16 < z < 0.42) clusters discovered via the Red-sequence
Cluster Survey (RCS). Surface brightness profiles are fitted to beta models,
gas masses are determined, integrated spectra are extracted within R2500, and
X-ray temperatures and luminosities are inferred. The Lx-Tx relationship
expected from self-similar evolution is tested by comparing this sample to our
previous X-ray investigation of nine high-redshift (0.6 < z < 1.0) optically
selected clusters. We find that optically selected clusters are systematically
less luminous than X-ray selected clusters of similar X-ray temperature at both
moderate and high-z. We are unable to constrain evolution in the Lx-Tx relation
with these data, but find it consistent with no evolution, within relatively
large uncertainties. To investigate selection effects, we compare the X-ray
properties of our sample to those of clusters in the representative X-ray
selected REXCESS sample, also determined within R2500. We find that while RCS
cluster X-ray properties span the entire range of those of massive clusters
selected by other methods, their average X-ray properties are most similar to
those of dynamically disturbed X-ray selected clusters. This similarity
suggests that the true cluster distribution might contain a higher fraction of
disturbed objects than are typically detected in X-ray selected surveys.


title: R Coronae Borealis Stars in M31 from the Palomar Transient Factory

abstract:
  We report the discovery of R Coronae Borealis (RCB) stars in the Andromeda
galaxy (M31) using the Palomar Transient Factory (PTF). RCB stars are rare
hydrogen-deficient, carbon-rich supergiant variables, most likely the merger
products of two white dwarfs. These new RCBs, including two confirmed ones and
two candidates, are the first to be found beyond the Milky Way and the
Magellanic Clouds. All of M31 RCBs showed >1.5 mag irregular declines over
timescales of weeks to months. Due to the limiting magnitude of our data
(R~21-22 mag), these RCB stars have R~19.5 to 20.5 mag at maximum light,
corresponding to M_R= -4 to -5, making them some of the most luminous RCBs
known. Spectra of two objects show that they are warm RCBs, similar to the
Milky Way RCBs RY Sgr and V854 Cen. We consider these results, derived from a
pilot study of M31 variables, as an important proof-of-concept for the study of
rare bright variables in nearby galaxies with the PTF or other synoptic
surveys.


title:
A force beyond the Standard Model - Status of the quest for hidden
  photons

abstract:
  In this note we discuss the search for new gauge forces beyond the Standard
Model. In particular we give an overview for the simplest case of a new U(1),
kinetically mixed with the Standard Model photon (hypercharge boson), a
so-called hidden photon (also known as dark photon, heavy photon or A').


title:
Natural Higgs-flavor-democracy solution of the mu problem of
  supersymmetry and the QCD axion

abstract:
  We show that the hierarchically small mu term in supersymmetric theories is a
consequence of two identical pairs of Higgs doublets taking a democratic form
for their mass matrix. We briefly discuss the discrete symmetry S2xS2 toward
the democratic mass matrix. Then, we show that there results an approximate
Peccei-Quinn symmetry and hence the value mu is related to the axion decay
constant.


title: Saturation of the MRI in Strongly Radiation Dominated Accretion Disks

abstract:
  The saturation level of the magneto-rotational instability (MRI) in a
strongly radiation dominated accretion disk is studied using a new Godunov
radiation MHD code in the unstratified shearing box approximation. Since
vertical gravity is neglected in this work, our focus is on how the MRI
saturates in the optically thick mid-plane of the disk. We confirm that
turbulence generated by the MRI is very compressible in the radiation dominated
regime, as found by previous calculations using the flux-limited diffusion
approximation. We also find little difference in the saturation properties in
calculations that use a larger horizontal domain (up to four times the vertical
scale height in the radial direction). However, in strongly radiation pressure
dominated disks (one in which the radiation energy density reaches 1% of the
rest mass energy density of the gas), we find Maxwell stress from the MRI
turbulence is larger than the value produced when radiation pressure is
replaced with the same amount of gas pressure. At the same time, the ratio
between Maxwell stress and Reynolds stress is increased by almost a factor of 8
compared with the gas pressure dominated case. We suggest that this effect is
caused by radiation drag, which acts like bulk viscosity and changes the
effective magnetic Prandtl number of the fluid. Radiation viscosity
significantly exceeds both the microscopic plasma viscosity and resistivity,
ensuring that radiation dominated systems occupy the high magnetic Prandtl
number regime. Nevertheless, we find radiative shear viscosity is negligible
compared to the Maxwell and Reynolds stress in the flow. This may have
important implications for the structure of radiation dominated accretion
disks.


title:
The VVV-SkZ pipeline: an automatic PSF-fitting photometric pipeline for
  the VVV survey

abstract:
  We present the VVV-SkZ_pipeline, a DAOPHOT-based photometric pipeline,
created to perform PSF-fitting photometry of "VISTA Variables in the V\'ia
L\'actea" (VVV) ESO Public Survey data. The pipeline replaces the user avoiding
repetitive interaction in all the operations, retaining all of the benefits of
the power and accuracy of the DAOPHOT suite. The pipeline provides an
astrometrized photometric catalog reliable up to more than 2 magnitudes
brighter than the saturation limit, where other techniques fail. It also
produces deeper and more accurate photometry. These achievements allow the
VVV-SkZ_pipeline to produce data well anchored to the selected standard
photometric system and analyze important phenomena (i.e. TRGB, RGB slope, HB
morphology, RR Lyrae), that other methods are not able to manage.


title:
Magnetic field diagnostics and spatio-temporal variability of the solar
  transition region

abstract:
  Magnetic field diagnostics of the transition region from the chromosphere to
the corona faces us with the problem that one has to apply extreme UV
spectro-polarimetry. While for coronal diagnostic techniques already exist
through infrared coronagraphy above the limb and radio observations on the
disk, for the transition region one has to investigate extreme UV observations.
However, so far the success of such observations has been limited, but there
are various projects to get spectro-polarimetric data in the extreme UV in the
near future. Therefore it is timely to study the polarimetric signals we can
expect for such observations through realistic forward modeling.
  We employ a 3D MHD forward model of the solar corona and synthesize the
Stokes I and Stokes V profiles of C IV 1548 A. A signal well above 0.001 in
Stokes V can be expected, even when integrating for several minutes in order to
reach the required signal-to-noise ratio, despite the fact that the intensity
in the model is rapidly changing (just as in observations). Often this
variability of the intensity is used as an argument against transition region
magnetic diagnostics which requires exposure times of minutes. However, the
magnetic field is evolving much slower than the intensity, and thus when
integrating in time the degree of (circular) polarization remains rather
constant. Our study shows the feasibility to measure the transition region
magnetic field, if a polarimetric accuracy on the order of 0.001 can be
reached, which we can expect from planned instrumentation.


title:
Possible relevance of quantum spacetime for neutrino-telescope data
  analyses

abstract:
  One of the primary goals of neutrino telescopes, such as IceCube, is the
discovery of neutrinos emitted by gamma-ray bursts (GRBs). Another source of
interest in the results obtained by these telescopes is their possible use for
tests of the applicability of Einstein's Special Relativity to neutrinos,
particularly with respect to modifications that lead to Lorentz invariance
violation that have been conjectured by some models of quantum space-time. We
examine here the fascinating scenario in which these two aspects of
neutrino-telescope physics require a combined analysis. We discuss how
neutrinos that one would not associate to a GRB, when assuming a classical
spacetime picture, may well be GRB neutrinos if the possibility that Lorentz
invariance is broken at very high energies is taken into account. As an
illustrative example we examine three IceCube high energy neutrinos that
arrived hours before GRBs (but from the same direction) and we find that the
available, IceCube data, while inconclusive, is compatible with a scenario in
which one or two of these neutrinos were GRB neutrinos and their earlier
arrival reflects Lorentz invariance violation.
  We outline how future analyses of neutrino data should be done in order to
systematically test this possibility.


title: Forensic Analysis of Phone Call Networks

abstract:
  In the context of preventing and fighting crime, the analysis of mobile phone
traffic, among actors of a criminal network, is helpful in order to reconstruct
illegal activities on the base of the relationships connecting those specific
individuals. Thus, forensic analysts and investigators require new advanced
tools and techniques which allow them to manage these data in a meaningful and
efficient way. In this paper we present LogAnalysis, a tool we developed to
provide visual data representation and filtering, statistical analysis features
and the possibility of a temporal analysis of mobile phone activities. Its
adoption may help in unveiling the structure of a criminal network and the
roles and dynamics of communications among its components. By using
LogAnalysis, forensic investigators could deeply understand hierarchies within
criminal organizations, for example discovering central members that provide
connections among different sub-groups, etc. Moreover, by analyzing the
temporal evolution of the contacts among individuals, or by focusing on
specific time windows they could acquire additional insights on the data they
are analyzing. Finally, we put into evidence how the adoption of LogAnalysis
may be crucial to solve real cases, providing as example a number of case
studies inspired by real forensic investigations led by one of the authors.


title: Discovering general multidimensional associations

abstract:
  When two variables are related by a known function, the coefficient of
determination (denoted $R^2$) measures the proportion of the total variance in
the observations that is explained by that function. This quantifies the
strength of the relationship between variables by describing what proportion of
the variance is signal as opposed to noise. For linear relationships, this is
equal to the square of the correlation coefficient, $\rho$. When the parametric
form of the relationship is unknown, however, it is unclear how to estimate the
proportion of explained variance equitably - assigning similar values to
equally noisy relationships. Here we demonstrate how to directly estimate a
generalized $R^2$ when the form of the relationship is unknown, and we question
the performance of the Maximal Information Coefficient (MIC) - a recently
proposed information theoretic measure of dependence. We show that our approach
behaves equitably, has more power than MIC to detect association between
variables, and converges faster with increasing sample size. Most importantly,
our approach generalizes to higher dimensions, which allows us to estimate the
strength of multivariate relationships ($Y$ against $A,B, ...$) and to measure
association while controlling for covariates ($Y$ against $X$ controlling for
$C$).


title: Watersheds on edge or node weighted graphs "par l'exemple"

abstract:
  Watersheds have been defined both for node and edge weighted graphs. We show
that they are identical: for each edge (resp.\ node) weighted graph exists a
node (resp. edge) weighted graph with the same minima and catchment basin.


title:
An Imprint of Molecular Cloud Magnetization in the Morphology of the
  Dust Polarized Emission

abstract:
  We describe a morphological imprint of magnetization found when considering
the relative orientation of the magnetic field direction with respect to the
density structures in simulated turbulent molecular clouds. This imprint was
found using the Histogram of Relative Orientations (HRO): a new technique that
utilizes the gradient to characterize the directionality of density and column
density structures on multiple scales. We present results of the HRO analysis
in three models of molecular clouds in which the initial magnetic field
strength is varied, but an identical initial turbulent velocity field is
introduced, which subsequently decays. The HRO analysis was applied to the
simulated data cubes and mock-observations of the simulations produced by
integrating the data cube along particular lines of sight. In the 3D analysis
we describe the relative orientation of the magnetic field $\mathbf{B}$ with
respect to the density structures, showing that: 1.The magnetic field shows a
preferential orientation parallel to most of the density structures in the
three simulated cubes. 2.The relative orientation changes from parallel to
perpendicular in regions with density over a critical density $n_{T}$ in the
highest magnetization case. 3.The change of relative orientation is largest for
the highest magnetization and decreases in lower magnetization cases. This
change in the relative orientation is also present in the projected maps. In
conjunction with simulations HROs can be used to establish a link between the
observed morphology in polarization maps and the physics included in
simulations of molecular clouds.


title: Grid Movies

abstract:
  We present a grid diagram analogue of Carter, Rieger and Saito's smooth movie
theorem. Specifically, we give definitions for grid movies, grid movie
isotopies and present a definition of grid planar isotopy as a particular
subset of the grid diagram moves: stabilization, destabilization and
commutation. We show that grid planar isotopy classes are in 1-1 correspondence
with smooth planar isotopy classes by using a new planar grid algorithm that
takes a smooth knot diagram to a grid diagram. We then present generalizations
of both the smooth and grid movie theorems that apply to surfaces with
boundary.


title: All Complete Intersection Calabi-Yau Four-Folds

abstract:
  We present an exhaustive, constructive, classification of the Calabi-Yau
four-folds which can be described as complete intersections in products of
projective spaces. A comprehensive list of 921,497 configuration matrices which
represent all topologically distinct types of complete intersection Calabi-Yau
four-folds is provided and can be downloaded at
http://www-thphys.physics.ox.ac.uk/projects/CalabiYau/Cicy4folds/index.html .
The manifolds have non-negative Euler characteristics in the range 0 - 2610.
This data set will be of use in a wide range of physical and mathematical
applications. Nearly all of these four-folds are elliptically fibered and are
thus of interest for F-theory model building.


title:
The Thousand Star Magnitudes in the Catalogues of Ptolemy, Al Sufi, and
  Tycho Are All Corrected For Atmospheric Extinction

abstract:
  Three pre-telescopic star catalogues contain about a thousand star magnitudes
each (with magnitudes 1, 2, 3, 4, 5, and 6), with these reported brightnesses
as the original basis for what has become the modern magnitude scale. These
catalogues are those of Ptolemy (c. 137, from Alexandria at a latitude of
31.2), Al Sufi (c. 960, from Isfahan at a latitude of 32.6), and Tycho Brahe
(c. 1590, from the island of Hven at a latitude of 55.9). Previously, extensive
work has been made on the positions of the catalogued stars, but only scant
attention has been paid to the magnitudes as reported. These magnitudes will be
affected by a variety of processes, including the dimming of the light by our
Earth's atmosphere (atmospheric extinction), the quantization of the
brightnesses into magnitude bins, and copying or influence from prior
catalogues. This paper provides a detailed examination of these effects.
Indeed, I find all three catalogues to report magnitudes that have near-zero
extinction effects, so the old observers in some way extinction corrected their
observations.


title:
Magnetic properties of the double perovskites LaPbMSbO6 (M = Mn, Co and
  Ni)

abstract:
  New double perovskites LaPbMSbO6, where M2+ = Mn2+, Co2+, and Ni2+, were
synthesized as polycrystals by an aqueous synthetic route at temperatures below
1000 oC. All samples are monoclinic, space group P21/n, as obtained from
Rietveld analysis of X-ray powder diffraction patterns. The distribution of M2+
and Sb5+ among the two octahedral sites have 3% of disorder for M2+ = Ni2+,
whereas for M2+ = Mn2+ and Co2+ less disorder is found. The three samples have
an antiferromagnetic transition, due to the antiferromagnetic coupling between
M2+ through super-superexchange paths M2+ - O2- - Sb5+ - O2- - M2+. Transition
temperatures are low: 8, 10 and 17 K for Mn2+, Co2+, and Ni2+ respectively, as
a consequence of the relatively long distances between the magnetic ions M2+.
Besides, for LaPbMnSbO6 a small transition at 45 K was found, with
ferrimagnetic characteristics, possibly as a consequence of a small disorder
between Mn2+ and Sb5+. This disorder would give additional and shorter
interaction paths: superexchange Mn2+ - O2- - Mn2+.


title: The Noncommutative Topology of Anti-Self-Dual Gauge Fields

abstract:
  Through techniques afforded by $C^*$-algebras and Hilbert modules, we study
the topology of spaces which parametrize families of instanton gauge fields on
noncommutative Euclidean four-spheres $S^4_\sigma$. By deforming the ADHM
construction of instantons on the classical sphere $S^4$, we obtain families of
instantons on the quantum sphere which are naturally parametrized by
noncommutative topological spaces. Using the internal gauge theory of
$S^4_\sigma$ determined by the inner automorphisms of its function algebra, we
find that one may always recover a classical parameter space by making a
suitable choice of internal gauge.


title:
The connection between polarization calculus and four-dimensional
  rotations

abstract:
  We review the well-known polarization optics matrix methods, i.e., Jones and
Stokes-Mueller calculus, and show how they can be formulated in terms of
four-dimensional (4d) rotations of the four independent electromagnetic field
quadratures. Since 4d rotations is a richer description than the conventional
Jones and Stokes-Mueller calculi, having six rather than four degrees of
freedom (DOF), we propose an extension of those calculi to handle all six DOF.
  For the Stokes-Mueller analysis, this leads to a novel and potentially useful
extension that accounts for the absolute phase of the optical field, and which
can be valuable in the areas where the optical phase is of interest, e.g.
interferometry or coherent communications. As examples of the usefulness we use
the formalism to explain the Pancharatnam phase by parallel transport, and
shows its connection with the Berry phase.
  In addition we show that the two extra DOF in the 4d description represents
unphysical transformations, forbidden for propagating photons, since they will
not obey the fundamental quantum mechanical boson commutation relations.


title:
The population of M-type supergiants in the starburst cluster Stephenson
  2

abstract:
  The open cluster Stephenson 2 contains the largest collection of red
supergiants known in the Galaxy, and at present is the second most massive
young cluster known in the Milky Way. We have obtained multi-epoch,
intermediate-resolution spectra around the CaII triplet for more than 30 red
supergiants in Stephenson~2 and its surroundings. We find a clear separation
between a majority of RSGs having spectral types M0-M2 and the brightest
members in the NIR, which have very late spectral types and show strong
evidence for heavy mass loss. The distribution of spectral types is similar to
that of RSGs in other clusters, such as NGC 7419, or associations, like Per
OB1. The cluster data strongly support the idea that heavy mass loss and maser
emission is preferentially associated with late-M spectral types, suggesting
that they represent an evolutionary phase.


title:
The Generalized Fibonacci and Lucas Solutions of The Pell Equations
  x^2-(a^2b^2-b)y^2=N and x^2-(a^2b^2-2b)y^2=N

abstract:
  In this study, we find continued fraction expansion of sqrt(d) when
d=a^2b^2-b and d=a^2b^2-2b where a and b are positive integers. We consider the
integer solutions of the Pell equations x^2-(a^2b^2-b)y^2=N and
x^2-(a^2b^2-2b)y^2=N when N is {+-1,+-4}. We formulate the n-th solution
(x_{n},y_{n}) by using the continued fraction expansion. We also formulate the
n-th solution (x_{n},y_{n}) in terms of generalized Fibonacci and Lucas
sequences.


title: Simultaneous Spin-Charge Relaxation in Double Quantum Dots

abstract:
  We investigate phonon-induced spin and charge relaxation mediated by
spin-orbit and hyperfine interactions for a single electron confined within a
double quantum dot. A simple toy model incorporating both direct decay to the
ground state of the double dot and indirect decay via an intermediate excited
state yields an electron spin relaxation rate that varies non-monotonically
with the detuning between the dots. We confirm this model with experiments
performed on a GaAs double dot, demonstrating that the relaxation rate exhibits
the expected detuning dependence and can be electrically tuned over several
orders of magnitude. Our analysis suggests that spin-orbit mediated relaxation
via phonons serves as the dominant mechanism through which the double-dot
electron spin-flip rate varies with detuning.


title: On Finding Lekkerkerker-Boland Subgraphs

abstract:
  Lekkerkerker and Boland characterized the minimal forbidden induced subgraphs
for the class of interval graphs. We give a linear-time algorithm to find one
in any graph that is not an interval graph. Tucker characterized the minimal
forbidden submatrices of matrices that do not have the consecutive-ones
property. We give a linear-time algorithm to find one in any matrix that does
not have the consecutive-ones property.


title:
H\"older continuity of pluricomplex Green function and Markov brothers'
  inequality

abstract:
  Let V_E be the pluricomplex Green function associated to a compact subset E
of C^N. The well known H\"older Continuity Property of E means that there exist
constants B > 0, 0< c =< 1 such that V_E(z) =< B dist(z,E)^c. The main result
of this paper says that this condition is equivalent to a Vladimir Markov type
inequality, i.e. || D^\alpha P ||_E =< M^{|\alpha |} (deg P)^{m|\alpha|}
(|\alpha |!)^{1-m} ||P||_E, where m,M>0 are independent of the polynomial P of
N variables. We give some applications of this equivalence and we present its
generalization related to a notion of a fit majorant. Moreover, as a
consequence of the main result we obtain a criterion for the H\"older
Continuity Property in several complex variables of the type of Siciak's
L-regularity criterion.


title: On the problem of classifying simple compact quantum groups

abstract:
  We review the notion of simple compact quantum groups and examples, and
discuss the problem of construction and classification of simple compact
quantum groups. Several new quantum groups constructed by Banica, Curran and
Speicher since the author's first paper on simple quantum groups are shown to
be simple using results of Raum and Weber.


title:
Classification of topological insulators and superconductors in the
  presence of reflection symmetry

abstract:
  We discuss a topological classification of insulators and superconductors in
the presence of both (non-spatial) discrete symmetries in the Altland-Zirnbauer
classification and spatial reflection symmetry in any spatial dimensions. By
using the structure of bulk Dirac Hamiltonians of minimal matrix dimensions and
explicit constructions of topological invariants, we provide the complete
classification, which still has the same dimensional periodicities with the
original Altland-Zirnbauer classification. The classification of
reflection-symmetry-protected topological insulators and superconductors
depends crucially on the way reflection symmetry operation is realized. When a
boundary is introduced, which is reflected into itself, these non-trivial
topological insulators and superconductors support gapless modes localized at
the boundary.


title:
Coherent molecule formation in anharmonic potentials near
  confinement-induced resonances

abstract:
  We perform a theoretical and experimental study of a system of two ultracold
atoms with tunable interaction in an elongated trapping potential. We show that
the coupling of center-of-mass and relative motion due to an anharmonicity of
the trapping potential leads to a coherent coupling of a state of an unbound
atom pair and a molecule with a center of mass excitation. By performing the
experiment with exactly two particles we exclude three-body losses and can
therefore directly observe coherent molecule formation. We find quantitative
agreement between our theory of inelastic confinement-induced resonances and
the experimental results. This shows that the effects of center-of-mass to
relative motion coupling can have a significant impact on the physics of
quasi-1D quantum systems.


title:
The Polonnaruwa meteorite: oxygen isotope, crystalline and biological
  composition

abstract:
  Results of X-Ray Diffraction (XRD) analysis, Triple Oxygen Isotope analysis
and Scanning Electron Microscopic (SEM) studies are presented for stone
fragments recovered from the North Central Province of Sri Lanka following a
witnessed fireball event on 29 December 2012. The existence of numerous
nitrogen depleted highly carbonaceous fossilized biological structures fused
into the rock matrix is inconsistent with recent terrestrial contamination.
Oxygen isotope results compare well with those of CI and CI-like chondrites but
are inconsistent with the fulgurite hypothesis.


title:
Transient Gamma-ray Emission from Cygnus X-3 Detected by AGILE: Leptonic
  and Hadronic Emission Models

abstract:
  The AGILE satellite detected several episodes of transient gamma-ray emission
from Cygnus X-3. Cross-correlating the AGILE light curve with both X-ray and
radio monitoring data, we found that the main events of gamma-ray activity were
detected while the system was in soft spectral X-ray states, that coincide with
local and often sharp minima of the hard X-ray flux, a few days before intense
radio outbursts. This repetitive temporal coincidence between the gamma-ray
transient emission and spectral state changes of the source turns out to be the
spectral signature of high-energy activity from this microquasar. The gamma-ray
differential spectrum of Cygnus X-3 (100 MeV - 3 GeV), which was obtained by
averaging the data collected by AGILE during the gamma-ray events, is
consistent with a power law of photon index {\alpha} = 2.0 +/- 0.2. Finally, we
examined leptonic and hadronic emission models for the gamma-ray activity and
found that both scenarios are valid. In particular, in the leptonic model -
based on inverse Compton scatterings of mildly relativistic electrons on soft
photons from both the Wolf-Rayet companion star and the accretion disk - the
emitting particles may also contribute to the overall hard X-ray spectrum,
possibly explaining the hard non-thermal power-law tail seen during special
soft X-ray states in Cygnus X-3.


title:
Random Subdictionaries and Coherence Conditions for Sparse Signal
  Recovery

abstract:
  The most frequently used condition for sampling matrices employed in
compressive sampling is the restricted isometry (RIP) property of the matrix
when restricted to sparse signals. At the same time, imposing this condition
makes it difficult to find explicit matrices that support recovery of signals
from sketches of the optimal (smallest possible)dimension. A number of attempts
have been made to relax or replace the RIP property in sparse recovery
algorithms. We focus on the relaxation under which the near-isometry property
holds for most rather than for all submatrices of the sampling matrix, known as
statistical RIP or StRIP condition. We show that sampling matrices of
dimensions $m\times N$ with maximum coherence $\mu=O((k\log^3 N)^{-1/4})$ and
mean square coherence $\bar \mu^2=O(1/(k\log N))$ support stable recovery of
$k$-sparse signals using Basis Pursuit. These assumptions are satisfied in many
examples. As a result, we are able to construct sampling matrices that support
recovery with low error for sparsity $k$ higher than $\sqrt m,$ which exceeds
the range of parameters of the known classes of RIP matrices.


title:
Blind Adaptive Beamforming Based on Constrained Constant Modulus RLS
  Algorithm for Smart Antennas

abstract:
  In this paper, we study the performance of blind adaptive beamforming
algorithms for smart antennas in realistic environments. A constrained constant
modulus (CCM) design criterion is described and used for deriving a recursive
least squares (RLS) type optimization algorithm. Furthermore, two kinds of
scenarios are considered in the paper for analyzing its performance.
Simulations are performed to compare the performance of the proposed method to
other well-known methods for blind adaptive beamforming. Results indicate that
the proposed method has a significant faster convergence rate, better
robustness to changeable environments and better tracking capability.


title: Revisiting the Nystrom Method for Improved Large-Scale Machine Learning

abstract:
  We reconsider randomized algorithms for the low-rank approximation of
symmetric positive semi-definite (SPSD) matrices such as Laplacian and kernel
matrices that arise in data analysis and machine learning applications. Our
main results consist of an empirical evaluation of the performance quality and
running time of sampling and projection methods on a diverse suite of SPSD
matrices. Our results highlight complementary aspects of sampling versus
projection methods; they characterize the effects of common data preprocessing
steps on the performance of these algorithms; and they point to important
differences between uniform sampling and nonuniform sampling methods based on
leverage scores. In addition, our empirical results illustrate that existing
theory is so weak that it does not provide even a qualitative guide to
practice. Thus, we complement our empirical results with a suite of worst-case
theoretical bounds for both random sampling and random projection methods.
These bounds are qualitatively superior to existing bounds---e.g. improved
additive-error bounds for spectral and Frobenius norm error and relative-error
bounds for trace norm error---and they point to future directions to make these
algorithms useful in even larger-scale machine learning applications.


title: The Herbig Ae SB2 System HD 104237

abstract:
  The double-lined spectroscopic binary HD 104237 (DX Cha) is part of a complex
system of some half-dozen nearby young stars. We report a significant change
from an orbit for the SB2 system derived from 1999-2000 observations. We obtain
abundances from the primary and secondary spectra. The abundance analysis uses
both detailed spectral synthesis and determinations based on equivalent widths
of weak absorption lines with W(lambda) typically < 25 mA. Abundances are
derived for 25 elements in the primary, and 17 elements in the secondary. Apart
from lithium and zirconium, abundances do not depart significantly from solar.
Lithium may be marginally enhanced with respect to the meteoritic value in the
primary. It somewhat depleted in the secondary. The emission-line spectrum is
typical of Herbig Ae stars. We compare and contrast the spectra of the HD
104237 primary and two other Herbig Ae stars with low v.sin(i), HD 101412 and
HD 190073.


title: Two solar flares that became X-ray plasma ejections

abstract:
  Solar flares and X-ray plasma ejections (XPEs) occur simultaneously but
usually are separated spatially. We present two exceptional events observed by
{\sl Yohkoh} in 2001 October 2 (event 1) and 2000 October 16 (event 2), in
which features of flares and XPEs are mixed. Namely, the soft and hard X-ray
images show intense sources of emission that move dynamically. Both events
occurred inside broad active regions showing complicated multi-level structure
reaching up to 200 Mm high. Both events show also similar four-stages
evolution: (1) a fast rise of a system of loops, (2) sudden changes in their
emission distribution, (3) a reconfiguration leading to liberation of large
amounts of plasma, (4) a small, static loop as the final remnant. Nevertheless,
the events are probably caused by different physical processes: emerging
magnetic flux plus reconnection (event 1) and reconnection plus ballooning
instability (event 2). Different is also the final destination of the ejected
plasma: in the event 1 overlying magnetic fields stop the ejection, in the
event 2 the ejection destabilizes the overall magnetic structure and forms a
coronal mass ejection (CME).


title:
Plastic response by dislocation glide in solid helium under dc strain
  rate loading

abstract:
  We develop a model for the gliding of dislocations and plasticity in solid
He-4. This model takes into account the Peierls barrier, multiplication and
interaction of dislocations, as well as classical thermally and mechanically
activated processes leading to dislocation glide. We specifically examine the
dc stress-strain curve and how it is affected by temperature, strain rate, and
dislocation density. As a function of temperature and shear strain, we observe
plastic deformation and discuss how this may be related to the experimental
observation of elastic anomalies in solid hcp He-4 that have been discussed in
connection with the possibility of supersolidity or giant plasticity. Our
theory gives several predictions for the dc stress strain curves, for example,
the yield point and the change in the work-hardening rate and plastic
dissipation peak, that can be compared directly to constant strain rate
experiments and thus provide bounds on model parameters.


title:
Integrable Discretisations for a Class of Nonlinear Schrodinger
  Equations on Grassmann Algebras

abstract:
  Integrable discretisations for a class of coupled (super) nonlinear
Schrodinger (NLS) type of equations are presented. The class corresponds to a
Lax operator with entries in a Grassmann algebra. Elementary Darboux
transformations are constructed. As a result, Grassmann generalisations of the
Toda lattice and the NLS dressing chain are obtained. The compatibility
(Bianchi commutativity) of these Darboux transformations leads to integrable
Grassmann generalisations of the difference Toda and NLS equations. The
resulting systems will have discrete Lax representations provided by the set of
two consistent elementary Darboux transformations. For the two discrete systems
obtained, initial value and initialboundary problems are formulated.


title:
Homogenization of the Oscillating Dirichlet Boundary Condition in
  General Domains

abstract:
  We prove the homogenization of the Dirichlet problem for fully nonlinear
elliptic operators with periodic oscillation in the operator and of the
boundary condition for a general class of smooth bounded domains. This extends
the previous results of Barles and Mironescu in half spaces. We show that
homogenization holds despite a possible lack of continuity in the homogenized
boundary data. The proof is based on a comparison principle with partial
Dirichlet boundary data which is of independent interest.


title: Simulating the Fermi sky: new results after 4 years in orbit

abstract:
  Detailed simulations of the gamma-ray sky played an important role before the
launch of Fermi. Pre-launch simulation campaigns aided the development of new
analysis tools and the assessment of the expected Fermi-LAT science
performance. After four years of the Fermi mission in orbit, improved sky
simulations can still be very useful to support the activities of Fermi, to
refine our understanding of the scientific performance and to explore potential
new science cases. We have used the LAT observations collected so far to
develop new, highly-detailed simulations of the sky as seen by LAT. These
simulations include the isotropic and Galactic diffuse emission, as well as the
list of point and extended sources detected by the LAT. Furthermore, our sky
simulations account for transient and variable sources, including Gamma Ray
Bursts, pulsars and flaring blazars. We report on the latest developments of
this new sky simulation work, describing its potential benefits for improving
the science of Fermi today and in the near future.


title: Euler's constant: Euler's work and modern developments

abstract:
  This paper has two parts. The first part surveys Euler's work on the constant
gamma=0.57721... bearing his name, together with some of his related work on
the gamma function, values of the zeta function and divergent series. The
second part describes various mathematical developments involving Euler's
constant, as well as another constant, the Euler-Gompertz constant. These
developments include connections with arithmetic functions and the Riemann
hypothesis, and with sieve methods, random permutations and random matrix
products. It includes recent results on Diophantine approximation and
transcendence related to Euler's constant.


title:
Chebyshev constants, transfinite diameter, and computation on complex
  algebraic curves

abstract:
  Notions of directional Chebyshev constant and transfinite diameter have
recently been studied on certain algebraic curves in $\mathbb{C}^2$. The theory
is extended here to curves in $\mathbb{C}^N$ for arbitrary $N$. The results are
analogous but require more methods from computational algebraic geometry.


title: On the Minimum Distance of Generalized Spatially Coupled LDPC Codes

abstract:
  Families of generalized spatially-coupled low-density parity-check (GSC-LDPC)
code ensembles can be formed by terminating protograph-based generalized LDPC
convolutional (GLDPCC) codes. It has previously been shown that ensembles of
GSC-LDPC codes constructed from a protograph have better iterative decoding
thresholds than their block code counterparts, and that, for large termination
lengths, their thresholds coincide with the maximum a-posteriori (MAP) decoding
threshold of the underlying generalized LDPC block code ensemble. Here we show
that, in addition to their excellent iterative decoding thresholds, ensembles
of GSC-LDPC codes are asymptotically good and have large minimum distance
growth rates.


title: A Cyclic Douglas-Rachford Iteration Scheme

abstract:
  In this paper we present two Douglas-Rachford inspired iteration schemes
which can be applied directly to N-set convex feasibility problems in Hilbert
space. Our main results are weak convergence of the methods to a point whose
nearest point projections onto each of the N sets coincide. For affine
subspaces, convergence is in norm. Initial results from numerical experiments,
comparing our methods to the classical (product-space) Douglas-Rachford scheme,
are promising.


title: Apolarity for determinants and permanents of generic symmetric matrices

abstract:
  We show that the apolar ideal to the determinant of a generic symmetric
matrix is generated in degree two, and the apolar ideal to the permanent of a
generic symmetric matrix is generated in degrees two and three. In each case we
specify the generators of the apolar ideal. As a consequence, using a result of
K. Ranestad and F. O. Schreyer we give lower bounds to the cactus rank and rank
of each of these polynomials. We compare these bounds with those obtained by J.
Landsberg and Z. Teitler.


title: Far-Infrared Properties of Type 1 Quasars

abstract:
  We use the Spitzer Space Telescope Enhanced Imaging Products (SEIP) and the
Spitzer Archival Far-InfraRed Extragalactic Survey (SAFIRES) to study the
spectral energy distributions of spectroscopically confirmed type 1 quasars
selected from the Sloan Digital Sky Survey (SDSS). By combining the Spitzer and
SDSS data with the 2-Micron All Sky Survey (2MASS) we are able to construct a
statistically robust rest-frame 0.1-100 micron type 1 quasar template. We find
the quasar population is well-described by a single power-law SED at
wavelengths less than 20 microns, in good agreement with previous work.
However, at longer wavelengths we find a significant excess in infrared
luminosity above an extrapolated power-law, along with signifiant
object-to-object dispersion in the SED. The mean excess reaches a maximum of
0.8 dex at rest-frame wavelengths near 100 microns.


title: A note on Ribaucour transformations in Lie sphere geometry

abstract:
  Following Burstall and Hertrich-Jeromin we study the Ribaucour transformation
of Legendre submanifolds in Lie sphere geometry. We give an explicit
parametrization of the resulted Legendre submanifold $\hat{F}$ of a Ribaucour
transformation, via a single real function $\tau$ which represents the regular
Ribaucour sphere congruence $s$ enveloped by the original Legendre submanifold
$F$.


title: A Gibbons-Penrose inequality for surfaces in Schwarzschild spacetime

abstract:
  We propose a geometric inequality for two-dimensional spacelike surfaces in
the Schwarzschild spacetime. This inequality implies the Penrose inequality for
collapsing dust shells in general relativity, as proposed by Penrose and
Gibbons. We prove that the inequality holds in several important cases.


title: Landau-Zener transitions in the presence of harmonic noise

abstract:
  We study the influence of off-diagonal harmonic noise on transitions in a
Landau-Zener model. We demonstrate that the harmonic noise can change the
transition probabilities substantially and that its impact depends strongly on
the characteristic frequency of the noise. In the underdamped regime of the
noise process, its effect is compared with the one of a deterministic
sinusoidally oscillating function. While altering the properties of the noise
process allows one to engineer the transitions probabilities, driving the
system with a deterministic sinusoidal function can result in larger and more
controlled changes of the transition probability. This may be relevant for
realistic implementations of our model with Bose-Einstein condensates in
noise-driven optical lattices.


title: Coronae of relatively hyperbolic groups and coarse cohomologies

abstract:
  We construct a corona of a relatively hyperbolic group by blowing-up all
parabolic points of its Bowditch boundary. We relate the $K$-homology of the
corona with the $K$-theory of the Roe algebra, via the coarse assembly map. We
also establish a dual theory, that is, we relate the $K$-theory of the corona
with the $K$-theory of the reduced stable Higson corona via the coarse
co-assembly map. For that purpose, we formulate generalized coarse cohomology
theories. As an application, we give an explicit computation of the $K$-theory
of the Roe-algebra and that of the reduced stable Higson corona of the
fundamental groups of closed 3-dimensional manifolds and of pinched negatively
curved complete Riemannian manifolds with finite volume.


title:
Determination of the Genus of Surfaces from the Spectrum of
  Schr\"odinger Operators attached to height functions. (An inverse spectral
  problem for surfaces)

abstract:
  Using results on inverse spectral problems, in particular the so-called new
wave invariants attached to a classical equilibrium, we show that it is
possible to determine the Morse index of height functions. For compact
Riemannian surfaces $M\subset \mathbb{R}^3$ this imply that we can retrieve the
topology (via the genus).
  Our results are independent from the choice of a metric on $M$ and can be
obtained from the choice of a 'generic' height-function. For surfaces of genus
zero, diffeomorphic to a 2-sphere, the method allows to detect the convexity,
or the local convexity of the surface.
  Keywords : Micro-local analysis; Schr\"odinger operators; Inverse spectral
problems.


title: Switching of a Quantum Dot Spin Valve by Single Molecule Magnets

abstract:
  We explore theoretically the spin transport in nanostructures consisting of a
gold quantum dot bridging nonmagnetic electrodes and two Mn12-Ph single
molecule magnets (SMMs) that are thiol-bonded to the dot but are not in direct
contact with the electrodes. We find that reversal of the magnetic moment of
either SMM by the application of a magnetic field leads to a large change in
the resistance of the dot, i.e., a strong spin valve effect. We show that this
phenomenon arises from a novel physical principle: The spin-dependent molecular
orbitals that extend over the dot and both SMMs change drastically when the
magnetic moment of either SMM is reversed, resulting in a large change in the
conduction via those orbitals. The same physics may also be responsible for the
spin valve phenomena discovered recently in carbon nanotube quantum dots with
rare earth SMMs by Urdampilleta, Klyatskaya, Cleuziou, Ruben and Wernsdorfer
[Nature Mater. 10, 502506 (2011)]


title:
Estimation of soil moisture in paddy field using Artificial Neural
  Networks

abstract:
  In paddy field, monitoring soil moisture is required for irrigation
scheduling and water resource allocation, management and planning. The current
study proposes an Artificial Neural Networks (ANN) model to estimate soil
moisture in paddy field with limited meteorological data. Dynamic of ANN model
was adopted to estimate soil moisture with the inputs of reference
evapotranspiration (ETo) and precipitation. ETo was firstly estimated using the
maximum, average and minimum values of air temperature as the inputs of model.
The models were performed under different weather conditions between the two
paddy cultivation periods. Training process of model was carried out using the
observation data in the first period, while validation process was conducted
based on the observation data in the second period. Dynamic of ANN model
estimated soil moisture with R2 values of 0.80 and 0.73 for training and
validation processes, respectively, indicated that tight linear correlations
between observed and estimated values of soil moisture were observed. Thus, the
ANN model reliably estimates soil moisture with limited meteorological data.


title: Speaking Plant Approach for Automatic Fertigation System in Greenhouse

abstract:
  Nowadays, many vegetables are grown insidegreenhouses in which environment is
controlled and nutrition can be supplied through water supply using electrical
pump, namely fertigation. Dosage of nutrition in water for many vegetable
plants are also known so that by controllingwater supply all the needsfor the
plants to grow are available. Furthermore, water supply can be controlled using
electrical pump which is activated according to theplants conditionin relation
with water supply. In order to supply water and nutrition in the right amount
and time, plants condition can be observed using a CCD camera attached to image
processing facilitiesto develop a speaking plant approach. In this study,
plants development during their growing periodare observedusing image
processing. Three populationsof tomato plants, with less, enough, and exceeded
nutrition in water,are captured using a CCD camera every three days, and the
images were analyzed using a developed computer program for the heightof
plants. The results showed that the development of the plants can be monitored
using this method. After that, the responseof plant growth in the same
condition was monitored, and the responsewas used as input for the fertigation
system to turn electrical pump automatically on and off, so the fertigation
system could maintain the growth of the plants.


title:
On Isodual Cyclic Codes over Finite Fields and Finite Chain Rings:
  Monomial Equivalence

abstract:
  This paper present the construction cyclic isodual codes over finite fields
and finite chain rings. These codes are monomially equivalent to their dual.
Conditions are given for the existence of cyclic isodual codes. In addition,
the concept of duadic codes over finite fields is extended to finite chain
rings. Several constructions of isodual cyclic codes and self-dual codes are
given.


title: Asymptotics of a cubic sine kernel determinant

abstract:
  We study the one parameter family of Fredholm determinants $\det(I-\gamma
K_{\textnormal{csin}}),\gamma\in\mathbb{R}$ of an integrable Fredholm operator
$K_{\textnormal{csin}}$ acting on the interval $(-s,s)$ whose kernel is a cubic
generalization of the sine kernel which appears in random matrix theory. This
Fredholm determinant appears in the description of the Fermi distribution of
semiclassical non-equilibrium Fermi states in condensed matter physics as well
as in random matrix theory. Using the Riemann-Hilbert method, we calculate the
large $s$-asymptotics of $\det(I-\gamma K_{\textnormal{csin}})$ for all values
of the real parameter $\gamma$.

categories: nlin.SI cond-mat.quant-gas math-ph math.MP


title:
An Efficient Dynamic Programming Algorithm for the Generalized LCS
  Problem with Multiple Substring Exclusion Constrains

abstract:
  In this paper, we consider a generalized longest common subsequence problem
with multiple substring exclusion constrains. For the two input sequences $X$
and $Y$ of lengths $n$ and $m$, and a set of $d$ constrains $P=\{P_1,...,P_d\}$
of total length $r$, the problem is to find a common subsequence $Z$ of $X$ and
$Y$ excluding each of constrain string in $P$ as a substring and the length of
$Z$ is maximized. The problem was declared to be NP-hard\cite{1}, but we
finally found that this is not true. A new dynamic programming solution for
this problem is presented in this paper. The correctness of the new algorithm
is proved. The time complexity of our algorithm is $O(nmr)$.


title: Magnetic response of mesoscopic rings: a quantum size effect

abstract:
  We analytically study the magnetic response of persistent current (PC) in
normally non-interacting mesoscopic rings of bimodal potential with nearest
neighboring interactions (t) and alternating site energies. It is shown that a
ring of perimeter (N) and width (M) generally shows weak diamagnetic, breaking
the even-odd rule of electron filling. Especially, a maximal paramagnetic
current in primary F0/2 period is predicted at N=(2p+1)(M+1) with odd M and
integer p, while a maximal diamagnetic F0/2- current obtained at
N=(2p+1)(M+1)+/-1 with even M. The current amplitudes depend strongly on both N
and M, varied by at least 1~2 orders of magnitude, exhibiting a remarkable
quantum size effect. A current limit of paramagnetic harmonics is expected at
N=2p(M+1), independent of the sizes of N and M, in favor of experiment
observation. A new mechanism of magnetic response is proposed that an electron
circling the ring shall pass successively each channel within one flux quantum,
accumulating an additional phase on each inter-channel transition, which leads
to the paramagnetic-diamagnetic transition and period halving. The results
unify and unveil the contradictions in PC between theory and experiments,
validating quantum mechanics at mesoscopic scale.


title:
Morphologies of low-redshift AGN host galaxies: what role does AGN
  luminosity play?

abstract:
  Mergers of galaxies have been suspected to be a major trigger of AGN activity
for many years. However, when compared to carefully matched control samples,
AGN host galaxies often show no enhanced signs of interaction. A common
explanation for this lack of observed association between AGN and mergers has
often been that while mergers are of importance for triggering AGN, they only
dominate at the very high luminosity end of the AGN population. In this study,
we compare the morphologies of AGN hosts to a carefully matched control sample
and particularly study the role of AGN luminosity. We find no enhanced merger
rates in AGN hosts and also find no trend for stronger signs of disturbance at
higher AGN luminosities. While this study does not cover very high luminosity
AGN, we can exclude a strong connection between AGN and mergers over a wide
range of AGN luminosities and therefore for a large part of the AGN population.


title:
Host galaxies of double-peaked [OIII] emitting AGN: binary AGN or
  mergers?

abstract:
  Mergers are suspected to be reliable triggers of both starformation and AGN
activity. However, the exact timing of this process remains poorly understood.
Here, we present deep imaging and long slit spectroscopy data of a sample of
four double-peaked [OIII] emitting AGN. These sources are often believed to
host binary AGN, or at least be currently undergoing major mergers. The sample
presented here either have previous IFU and high resolution imaging data that
show double-nuclei in the IR as well as kinematicly and spatially distinct line
emitting regions. Two sources have detections of double point sources in either
the X-ray or radio. The sources studied are therefore likely binary AGN. The
AGN in this sample are luminous, radio-quiet and at low redshift. The $u/r/z$
imaging data show host galaxies in a wide range of merger stages, with the
majority (3/4) showing tidal tails or complex kinematics and morphologies
clearly indicating a recent merger. One source however -hosting a double X-ray
source- shows quiescent morphologies with no clear signs of interaction from
imaging data. The spectroscopy in this case reveals a gas disk counter-rotating
with respect to the stellar component. Spectroscopy of the other sources reveal
disturbed kinematics further confirming their status as ongoing mergers. Our
data show that AGN triggering in mergers may happen over a wide time span and
that sinking of black holes to the center of a merged system might take
considerable time in some cases. A detailed analysis will be published in an
upcoming paper. Further studies of AGN in merging galaxies will show how the
hosts of those AGN differ from normal mergers without AGN activity.


title: HST and Optical Data on SDSSJ0804+5103 (EZ Lyn) One Year after Outburst

abstract:
  We present an ultraviolet spectrum and light curve of the short orbital
period cataclysmic variable EZ Lyn obtained with the Cosmic Origins
Spectrograph on the Hubble Space Telescope 14 months after its dwarf nova
outburst, along with ground-based optical photometry. The UV spectrum can be
fit with a 13,100K, log g=8 white dwarf using 0.5 solar composition, while fits
to the individual lines are consistent with solar abundance for Si and Al, but
only 0.3 solar for C. The Discrete Fourier Transforms of the UV and optical
light curves at 14 months following outburst show a prominent period at 256
sec. This is the same period reported by Pavlenko in optical data obtained 7
months and one year after outburst, indicating its long term stability over
several months, but this period is not evident in the pre-outburst data and is
much shorter than the 12.6 min period that was seen in observations obtained
during an interval from 8 months to 2.5 years after the 2006 outburst. In some
respects, the long and short periods are similar to the behavior seen in GW Lib
after its outburst but the detailed explanation for the appearance and
disappearance of these periods and their relation to non-radial pulsation modes
remain to be explored with theoretical models.


title:
A logarithmically completely monotonic function involving the ratio of
  gamma functions

abstract:
  In the paper, the authors concisely survey and review some functions
involving the gamma function and its various ratios, simply state their
logarithmically complete monotonicity and related results, and find necessary
and sufficient conditions for a new function involving the ratio of two gamma
functions and originating from the coding gain to be logarithmically completely
monotonic.


title:
Equivalent Notions of Normal Quantum Subgroups, Compact Quantum Groups
  with Properties F and FD, and Other Applications

abstract:
  The notion of normal quantum subgroup introduced in algebraic context by
Parshall and Wang when applied to compact quantum groups is shown to be
equivalent to the notion of normal quantum subgroup introduced by the author.
As applications, a quantum analog of the third fundamental isomorphism theorem
for groups is obtained, which is used along with the equivalence theorem to
obtain results on structure of quantum groups with property F and quantum
groups with property FD. Other results on normal quantum subgroups for tensor
products, free products and crossed products are also proved.


title: A $q$-Queens Problem. I. General Theory

abstract:
  By means of the Ehrhart theory of inside-out polytopes we establish a general
counting theory for nonattacking placements of chess pieces with unbounded
straight-line moves, such as the queen, on a polygonal convex board. The number
of ways to place $q$ identical nonattacking pieces on a board of variable size
$n$ but fixed shape is given by a quasipolynomial function of $n$, of degree
$2q$, whose coefficients are polynomials in $q$. The number of combinatorially
distinct types of nonattacking configuration is the evaluation of our
quasipolynomial at $n=-1$. The quasipolynomial has an exact formula that
depends on a matroid of weighted graphs, which is in turn determined by
incidence properties of lines in the real affine plane. We study the
highest-degree coefficients and also the period of the quasipolynomial, which
is needed if the quasipolynomial is to be interpolated from data, and which is
bounded by some function, not well understood, of the board and the piece's
move directions.
  In subsequent parts we specialize to the square board and then to subsets of
the queen's moves, and we prove exact formulas (most but not all already known
empirically) for small numbers of queens, bishops, and nightriders.
  Each part concludes with open questions, both specialized and broad.


title: A Simple Algorithm for Global Value Numbering

abstract:
  Global Value Numbering(GVN) is a method for detecting redundant computations
in programs. Here, we introduce the problem of Global Value Numbering in its
original form, as conceived by Kildall(1973), and present an algorithm which is
a simpler variant of Kildall's. The algorithm uses the concept of value
expression - an abstraction of a set of expressions - enabling a representation
of the equivalence information which is compact and simple to manipulate.


title: New Constraints on Anisotropic Rotation of CMB Polarization

abstract:
  The coupling of a scalar field to electromagnetic field via the Chern-Simons
term will rotate the polarization directions of the cosmic microwave background
radiation. The rotation angle which relies on the distribution of the scalar
field on the CMB sky is direction dependent. Such anisotropies will give rise
to new distortions to the power spectra of CMB polarization and it can be used
to probe the detailed physics of the scalar field. In this paper we use the
updated observational data to constrain the anisotropic rotation angle in a
model independent way. We find that the dominant effect of the anisotropic
rotation on CMB comes from its variance and it is constrained tightly by the
current data.


title: An Overview of Wireless Local Area Network (WLAN)

abstract:
  Wireless Communication is an application of science and technology that has
come to be vital for modern existence. From the early radio and telephone to
current devices such as mobile phones and laptops, accessing the global network
has become the most essential and indispensable part of our lifestyle. Wireless
communication is an ever developing field, and the future holds many
possibilities in this area. One expectation for the future in this field is
that, the devices can be developed to support communication with higher data
rates and more security. Research in this area suggests that a dominant means
of supporting such communication capabilities will be through the use of
Wireless LANs. As the deployment of Wireless LAN increases well around the
globe, it is increasingly important for us to understand different technologies
and to select the most appropriate one.
  This paper provides a detailed study of the available wireless LAN
technologies and the concerned issues, will give a brief description of what
wireless LANs are, the need of Wireless LAN, History of wireless LAN,
advantages of Wireless Networks, with summarizing the related work on WLAN in
academic area, Wireless LAN technologies, some risks attacks against wireless
technologies, suggesting some recommendations to protect wireless LAN network
from attack, Finally we propose some research issues should be focused on in
the future.


title: Real-time On and Off Road GPS Tracking

abstract:
  This document describes a GPS-based tracking model for position and velocity
states on and off of a road network and it enables parallel, online learning of
state-dependent parameters, such as GPS error, acceleration error, and road
transition probabilities. More specifically, the conditionally linear tracking
model of Ulmke and Koch (2006) is adapted to the Particle Learning framework of
H. F. Lopes, et. al. (2011), which provides a foundation for further
hierarchical Bayesian extensions. The filter is shown to perform well on a real
city road network while sufficiently estimating on and off road transition
probabilities. The model in this paper is also backed by an open-source Java
project.


title: Entanglement entropy from the holographic stress tensor

abstract:
  We consider entanglement entropy in the context of gauge/gravity duality for
conformal field theories in even dimensions. The holographic prescription due
to Ryu and Takayanagi (RT) leads to an equation describing how the entangling
surface extends into the bulk geometry. We show that setting to zero the
time-time component of the Brown-York stress tensor evaluated on the
co-dimension one entangling surface, leads to the same equation. By considering
a spherical entangling surface as an example, we observe that Euclidean action
methods in AdS/CFT will lead to the RT area functional arising as a counterterm
needed to regularize the stress tensor. We present arguments leading to a
justification for the minimal area prescription.


title:
Unitarity of Maxwell theory on curved spacetimes in the covariant
  formalism

abstract:
  Quantum field theory in curved spacetime may be defined either through a
manifestly unitary canonical approach or via the manifestly covariant path
integral formalism. For gauge theories, these two approaches have produced
conflicting results, leading to the question of whether the canonical approach
is covariant, and whether the path integral approach is unitary. We show the
unitarity of the covariant U(1) Maxwell theory, defined via the Wick rotation
of a Euclidean path integral. We begin by gauge-fixing the path integral,
taking care with zero modes, large gauge transformations, and nontrivial
bundles. We find an extra geometric factor in the partition function that has
been overlooked in previous work, coming from the zero mode of the gauge
symmetry, which affects the entropy and stress-energy tensor. With this extra
factor, the covariant calculation agrees with the canonical result for
ultrastatic manifolds, and in D = 2. Finally, we argue that if there exists a
unitary (but not necessarily covariant) canonical formulation, then the
covariant formulation must also be unitary, even if the two approaches
disagree.