title:
Extensions of Lorentzian spacetime geometry: From Finsler to Cartan and
  vice versa

abstract:
  We briefly review two recently developed extensions of the Lorentzian
geometry of spacetime and prove that they are in fact closely related. The
first is the concept of observer space, which generalizes the space of
Lorentzian observers, i.e., future unit timelike vectors, using Cartan
geometry. The second is the concept of Finsler spacetimes, which generalizes
the Lorentzian metric of general relativity to an observer-dependent Finsler
metric. We show that every Finsler spacetime possesses a well-defined observer
space that can naturally be equipped with a Cartan geometry. Conversely, we
derive conditions under which a Cartan geometry on observer space gives rise to
a Finsler spacetime. We further show that these two constructions complement
each other. We finally apply our constructions to two gravity theories,
MacDowell-Mansouri gravity on observer space and Finsler gravity, and translate
their actions from one geometry to the other.


title: The radiation belt of the Sun

abstract:
  For a given solar magnetic field, the near-Sun (phase-space) density of
cosmic ray electrons and positrons of energy above about 10GeV can be
calculated from first principles, without any assumptions about the cosmic ray
diffusion. This is because the sunlight Compton drag must be more important
than diffusion. If the solar magnetic field has an appreciable dipole
component, the electron/positron density should have a belt-like dent, perhaps
extending to several solar radii. The belt structure appears because the
quasi-bound orbits are depopulated by the sunlight Compton drag.


title: Stability of 248-254^Cf isotopes against alpha and cluster radioactivity

abstract:
  Stability of 248-254^Cf nuclei against alpha and cluster emission is studied
within our Coulomb and proximity potential model (CPPM). It is found that these
nuclei are stable against light clusters (except alpha particle) and instable
against heavy cluster emissions. For heavy cluster emissions the daughter
nuclei lead to doubly magic 208^Pb or neighbouring one. The effect of
quadrapole and hexadecapole deformations of parent nuclei, daughter nuclei and
emitted cluster on half lives are also studied. The computed alpha decay half
life values (with including quadrupole deformation {\beta}2) are in close
agreement with experimental data. Inclusion of quadrupole deformation reduces
the height and width of the barrier (increases the barrier penetrability) and
hence half life decreases.


title: Environmental CPT Violation in an Expanding Universe in String Theory

abstract:
  We consider a model of an expanding Universe in string theory that yields
`environmental' CPT violation for fermions, in the sense of different
dispersion relations for fermions and antifermions. These are induced by a
cosmological background with constant torsion provided by the Kalb-Ramond
antisymmetric tensor field (axion) of the string gravitational multiplet. This
effect induces different densities of neutrinos and antineutrinos while in
chemical equilibrium, offering new scenarios for leptogenesis and baryogenesis
even in the absence of CP violation.


title: Algebraic characterization of differential operators of Calabi-Yau type

abstract:
  We give an algebraic characterization of Picard-Fuchs operators attached to
families of Calabi-Yau manifolds with a point of maximally unipotent monodromy
and discuss possibilities for their differential Galois groups.


title: The ACS LCID Project. VIII. The short-period Cepheids of Leo A

abstract:
  We present the results of a new search for variable stars in the Local Group
dwarf galaxy Leo A, based on deep photometry from the Advanced Camera for
Surveys onboard the Hubble Space Telescope. We detected 166 bona fide variables
in our field, of which about 60 percent are new discoveries, and 33 candidate
variables. Of the confirmed variables, we found 156 Cepheids, but only 10 RR
Lyrae stars despite nearly 100 percent completeness at the magnitude of the
horizontal branch. The RR Lyrae stars include 7 fundamental and 3
first-overtone pulsators, with mean periods of 0.636 and 0.366 day,
respectively. From their position on the period-luminosity (PL) diagram and
light-curve morphology, we classify 91, 58, and 4 Cepheids as fundamental,
first-overtone, and second-overtone mode Classical Cepheids (CC), respectively,
and two as population II Cepheids. However, due to the low metallicity of Leo
A, about 90 percent of the detected Cepheids have periods shorter than 1.5
days. Comparison with theoretical models indicate that some of the fainter
stars classified as CC could be Anomalous Cepheids. We estimate the distance to
Leo A using the tip of the RGB (TRGB) and various methods based on the
photometric and pulsational properties of the Cepheids and RR Lyrae stars. The
distances obtained with the TRGB and RR Lyrae stars agree well with each other
while that from the Cepheid PL relations is somewhat larger, which may indicate
a mild metallicity effect on the luminosity of the short-period Cepheids. Due
to its very low metallicity, Leo A thus serves as a valuable calibrator of the
metallicity dependencies of the variable star luminosities.


title:
ALMA detection of the rotating molecular disk wind from the young star
  HD 163296

abstract:
  Disk winds have been postulated as a mechanism for angular momentum release
in protostellar systems for decades. HD 163296 is a Herbig Ae star surrounded
by a disk and has been shown to host a series of HH knots (HH 409) with bow
shocks associated with the farthest knots. Here we present ALMA Science
Verification data of CO J=2-1 and J=3-2 emission which are spatially coincident
with the blue shifted jet of HH knots, and offset from the disk by -18.6 km/s.
The emission has a double corkscrew morphology and extends more than 10" from
the disk with embedded emission clumps coincident with jet knots. We interpret
this double corkscrew as emission from material in a molecular disk wind, and
that the compact emission near the jet knots is being heated by the jet which
is moving at much higher velocities. We show that the J=3-2 emission is likely
heavily filtered by the interferometer, but the J=2-1 emission suffers less due
to the larger beam and measurable angular scales. Excitation analysis suggests
temperatures exceeding 900 K in these compact features, with the wind mass,
momentum and energy being of order 10^{-5} M_sun, 10^{-4} M_sun km/s and
10^{40} erg respectively. The high mass loss rate suggests that this star is
dispersing the disk faster than it is funneling mass onto the star.


title: New Regions in the NMSSM with a 125 GeV Higgs

abstract:
  It is pointed out that mixing effects in the CP-even scalar sector of the
NMSSM can give 6-8 GeV correction to the SM-like Higgs mass in moderate or
large $\tan\beta$ regions with a small value of the singlet-higgs-higgs
superfields coupling $\lambda\sim\mathcal{O}(0.1)$. This effect comes mainly
from the mixing of the SM-like Higgs with lighter singlet. In the same
parameter range, the mixing of the heavy doublet Higgs with the singlet may
strongly modify the couplings of the singlet-like and the 125 GeV scalars.
Firstly, the LEP bounds on a light singlet can be evaded for a large range of
its masses. Secondly, the decay rates of both scalars can show a variety of
interesting patterns, depending on the lightest scalar mass. In particular, a
striking signature of this mechanism can be a light scalar with strongly
suppressed (enhanced) branching ratios to $b\bar{b}$ ($gg$, $c\bar{c}$,
$\gamma\gamma$) as compared to the SM Higgs with the same mass. The
$\gamma\gamma$ decay channel is particularly promising for the search of such a
scalar at the LHC. The 125 GeV scalar can, thus, be accommodated with
substantially smaller than in the MSSM radiative corrections from the stop
loops (and consequently, with lighter stops) also for moderate or large
$\tan\beta$, with the mixing effects replacing the standard NMSSM mechanism of
increasing the tree level Higgs mass in the low $\tan\beta$ and large $\lambda$
regime, and with clear experimental signatures of such a mechanism.


title: Simple strategies for Banach-Mazur games and fairly correct systems

abstract:
  In 2006, Varacca and V\"olzer proved that on finite graphs, omega-regular
large sets coincide with omega-regular sets of probability 1, by using the
existence of positional strategies in the related Banach-Mazur games. Motivated
by this result, we try to understand relations between sets of probability 1
and various notions of simple strategies (including those introduced in a
recent paper of Gr\"adel and Lessenich). Then, we introduce a generalisation of
the classical Banach-Mazur game and in particular, a probabilistic version
whose goal is to characterise sets of probability 1 (as classical Banach-Mazur
games characterise large sets). We obtain a determinacy result for these games,
when the winning set is a countable intersection of open sets.


title:
Modeling the Line-of-Sight Integrated Emission in the Corona:
  Implications for Coronal Heating

abstract:
  One of the outstanding problems in all of space science is uncovering how the
solar corona is heated to temperatures greater than 1 MK. Though studied for
decades, one of the major difficulties in solving this problem has been
unraveling the line-of-sight (LOS) effects in the observations. The corona is
optically thin, so a single pixel measures counts from an indeterminate number
(perhaps tens of thousands) of independently heated flux tubes, all along that
pixel's LOS. In this paper we model the emission in individual pixels imaging
the active region corona in the Extreme Ultraviolet. If LOS effects are not
properly taken into account, erroneous conclusions regarding both coronal
heating and coronal dynamics may be reached. We model the corona as a LOS
integration of many thousands of completely independently heated flux tubes. We
demonstrate that despite the superposition of randomly heated flux tubes,
nanoflares leave distinct signatures in light curves observed with
multi-wavelength and high time cadence data, such as those data taken with the
Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. These
signatures are readily detected with the time-lag analysis technique of Viall &
Klimchuk (2012). Steady coronal heating leaves a different and equally distinct
signature that is also revealed by the technique.


title: Higher-Order Gauss-Bonnet Cosmology

abstract:
  We study cosmological models derived from higher-order Gauss-Bonnet gravity
$F(R,G)$ by using the Lagrange multiplier approach without assuming the
presence of additional fields with the exception of standard perfect fluid
matter. The presence of Lagrange multipliers reduces the number of allowed
solutions. We need to introduce compatibility conditions of the FRW equations,
which impose strict restrictions on the metric or require the introduction of
additional exotic matter. Several classes of $F(R,G)$ models are generated and
discussed.


title:
Comments to a series of works by V.K. Mukhomorov on the theory of a
  continuum polaron and two-center bipolaron (axially symmetrical
  quasimolecular dimer)

abstract:
  Some critical remarks are made regarding a series of works by V.K. Mukhomorov
dealing with polarons and oscillatory and rotational spectrum of a large-radius
bipolaron near a subsidiary minimum corresponding to its two-center
configuration. It is shown that V.K. Mukhomorov's conclusion that by varying
the bipolaron functional one should look for a constrained rather than absolute
minimum is erroneous. Consideration of interelectronic correlations
corresponding to a direct dependence of the wave function of the studied system
on the distance between the electrons does not break the virial theorem. In the
strong coupling limit the virial theorem holds true for both one-center and
two-center bipolaron states, the latter representing a subsidiary minimum which
arises due to a choice of an insufficiently versatile variation function.


title:
First Measurements of Spin-Dependent Double-Differential Cross Sections
  and the GDH Integrand from \vec{^3He}(\vec{\gamma},n)pp at Incident Photon
  Energies of 12.8 and 14.7 MeV

abstract:
  The first measurement of the three-body photodisintegration of
longitudinally-polarized ^3He with a circularly-polarized \gamma-ray beam was
carried out at the High Intensity \gamma-ray Source (HI\gamma S) facility
located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent
double-differential cross sections and the contributions from the three-body
photodisintegration to the ^3He GDH integrand are presented and compared with
state-of-the-art three-body calculations at the incident photon energies of
12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb
interaction between protons in three-body calculations.


title:
Joint reconstruction of galaxy clusters from gravitational lensing and
  thermal gas I. Outline of a non-parametric method

abstract:
  We present a method to estimate the lensing potential from massive galaxy
clusters for given observational X-ray data. The concepts developed and applied
in this work can easily be combined with other techniques to infer the lensing
potential, e.g. weak gravitational lensing or galaxy kinematics, to obtain an
overall best fit model for the lensing potential. After elaborating on the
physical details and assumptions the method is based on, we explain how the
numerical algorithm itself is implemented with a Richardson-Lucy algorithm as a
central part. Our reconstruction method is tested on simulated galaxy clusters
with a spherically symmetric NFW density profile filled with gas in hydrostatic
equilibrium. We describe in detail how these simulated observational data sets
are created and how they need to be fed into our algorithm. We test the
robustness of the algorithm against small parameter changes and estimate the
quality of the reconstructed lensing potentials. As it turns out we achieve a
very high degree of accuracy in reconstructing the lensing potential. The
statistical errors remain below 2.0% whereas the systematical error does not
exceed 1.0%.


title:
Characteristically simple Beauville groups, I: cartesian powers of
  alternating groups

abstract:
  A Beauville surface (of unmixed type) is a complex algebraic surface which is
the quotient of the product of two curves of genus at least 2 by a finite group
G acting freely on the product, where G preserves the two curves and their
quotients by G are isomorphic to the projective line, ramified over three
points. Such a group G is called a Beauville group. We show that if a
characteristically simple group G is a cartesian power of a finite simple
alternating group, then G is a Beauville group if and only if it has two
generators and is not isomorphic to A_5.


title: New Massive Supergravity and Auxiliary Fields

abstract:
  We construct a supersymmetric formulation of linearized New Massive Gravity
without introducing higher derivatives. Instead, we introduce
supersymmetrically a set of bosonic and fermionic auxiliary fields which, upon
elimination by their equations of motion, introduce fourth-order derivative
terms for the metric and third-order derivative terms for the gravitino. Our
construction requires an off-shell formulation of the three-dimensional
supersymmetric massive Fierz-Pauli theory. We discuss the non-linear extension
of our results.


title: Scale invariance at the onset of turbulence in Couette flow

abstract:
  Laminar-turbulent intermittency is intrinsic to the transitional regime of a
wide range of fluid flows including pipe, channel, boundary layer and Couette
flow. In the latter turbulent spots can grow and form continuous stripes, yet
in the stripe-normal direction they remain interspersed by laminar fluid. We
carry out direct numerical simulations in a long narrow domain and observe that
individual turbulent stripes are transient. In agreement with recent
observations in pipe flow we find that turbulence becomes sustained at a
distinct critical point once the spatial proliferation outweighs the inherent
decaying process. By resolving the asymptotic size distributions close to
criticality we can for the first time demonstrate scale invariance at the onset
of turbulence.


title:
On a representation of the fundamental class of an ideal due to
  Lejeune-Jalabert

abstract:
  Lejeune-Jalabert showed that the fundamental class of a Cohen-Macaulay ideal
$\mathfrak a\subset \mathcal O_0$ admits a representation as a residue,
constructed from a free resolution of $\mathfrak a$, multiplied by a certain
differential form coming from the resolution. We give an explicit description
of this differential form in the case where the free resolution is the Scarf
resolution of a generic monomial ideal. As a consequence we get a new proof and
a refinement of Lejeune-Jalabert's result in this case.


title: Dynamics of Charge Transfer in Ordered and Chaotic Nucleotide Sequences

abstract:
  Charge transfer is considered in systems composed of a donor, an acceptor and
bridge sites of (AT) nucleotide pairs. For a bridge consisting of 180 (AT)
pairs, three cases are dealt with: a uniform case, when all the nucleotides in
each strand are identical; an ordered case, when nucleotides in each DNA strand
are arranged in an orderly fashion; a chaotic case, when (AT) and (TA) pairs
are arranged randomly. It is shown that in all the cases a charge transfer from
a donor to an acceptor can take place. All other factors being equal, the
transfer is the most efficient in the uniform case, the ordered and chaotic
cases are less and the least efficient, accordingly. The results obtained are
in agreement with experimental data on long-range charge transfer in DNA.


title: Solving WCSP by Extraction of Minimal Unsatisfiable Cores

abstract:
  Usual techniques to solve WCSP are based on cost transfer operations coupled
with a branch and bound algorithm. In this paper, we focus on an approach
integrating extraction and relaxation of Minimal Unsatisfiable Cores in order
to solve this problem. We decline our approach in two ways: an incomplete,
greedy, algorithm and a complete one.


title:
Characteristically simple Beauville groups, II: low rank and sporadic
  groups

abstract:
  A Beauville surface is a rigid complex surface of general type, isogenous to
a higher product by the free action of a finite group, called a Beauville
group. Here we consider which characteristically simple groups can be Beauville
groups. We show that if G is a cartesian power of a simple group L_2(q),
L_3(q), U_3(q), Sz(2^e), R(3^e), or of a sporadic simple group, then G is a
Beauville group if and only if it has two generators and is not isomorphic to
A_5.


title: Subradiant hybrid states in the open 3D Anderson-Dicke model

abstract:
  Anderson localization is a paradigmatic coherence effect in disordered
systems, often analyzed in the absence of dissipation. Here we consider the
case of coherent dissipation, occurring for open system with coupling to a
common decay channel. This dissipation induces cooperative Dicke super- and
subradiance and an effective long range hopping, expected to destroy Anderson
localization. We are thus in presence of two competing effects, i.e
localization driven by disorder and delocalization driven by dissipative
opening. Here we demonstrate the existence of a {\it subradiant hybrid regime},
emerging from the interplay of opening and disorder, in which subradiant states
are {hybrid with both features of localized and extended states}, while
superradiant states are extended. We also provide analytical predictions for
this regime, confirmed by numerical simulations.


title:
All-electrical spin injection and detection in the Co2FeSi/GaAs hybrid
  system in the local and non-local configuration

abstract:
  We demonstrate the electrical injection and detection of spin-polarized
electrons in the Co2FeSi/GaAs hybrid system using lateral transport structures.
Spin valve signatures and characteristic Hanle curves are observed both in the
nonlocal and the local configuration. The comparatively large magnitude of the
local spin valve signal and the high signal-to-noise ratio are attributed to
the large spin polarization at the Fermi energy of Co2FeSi in the well-ordered
L21 phase.


title: A permutation approach for ranking of multivariate populations

abstract:
  The subject of this paper is to introduce a novel permutation-based
nonparametric approach for the problem of ranking several multivariate
populations with respect to both experimental and observation studies to be
referred to the most useful design such as MANOVA (multivariate independent
samples) and MRCB (multivariate randomized complete block design, i.e.
multivariate dependent samples also known as repeated measures). This topic is
not only of theoretical interest but also have a practical relevance,
especially to business and industrial research where a reliable global ranking
in terms of performance of all investigated products/prototypes is a very
natural goal. In fact, the need to define an appropriate ranking of items
(products, services, teaching courses, degree programs, and so on) is very
common in both experimental and observational studies within the areas of
business and industrial research.


title:
Universal behaviour of four-boson systems from a functional
  renormalisation group

abstract:
  We apply a functional renormalisation group to systems of four bosonic atoms
close to the unitary limit. We work with a local effective action that includes
a dynamical trimer field and we use this field to eliminate structures that do
not correspond to the Faddeev-Yakubovsky equations. In the physical limit, we
find three four-body bound states below the shallowest three-body state. The
values of the scattering lengths at which two of these states become bound are
in good agreement with exact solutions of the four-body equations and
experimental observations. The third state is extremely shallow. During the
evolution we find an infinite number of four-body states based on each
three-body state which follow a double-exponential pattern in the running
scale. None of the four-body states shows any evidence of dependence on a
four-body parameter.


title: Probability and strategy in a variation of a blackjack game

abstract:
  The subject of this paper is a variation of a blackjack game, mainly popular
in some parts of Europe where it is known as einz (in German slang: one). We
describe the rules of this game, indicate its main characteristics, give some
probabilities, suggest the strategy, and consider some typical situations.


title: Fermi-LAT data reprocessed with updated calibration constants

abstract:
  Four years into the mission, the understanding of the performance of the
Fermi Large Area Telescope (LAT) and data analysis have increased enormously
since launch. Thanks to a careful analysis of flight data, we were able to
trace back some of the most significant sources of systematic uncertainties to
using non-optimal calibration constants for some of the detectors. In this
paper we report on a major effort within the LAT Collaboration to update these
constants, to use them to reprocess the first four years of raw data, and to
investigate the improvements observed for low- and high-level analysis. The
Pass 7 reprocessed data, also known as P7REP data, are still being validated
against the original Pass~7 (P7) data by the LAT Collaboration and should be
made public, along with the corresponding instrument response functions, in the
spring of 2013.


abstract:
  A huge number of academic papers are coming out from a lot of conferences and
journals these days. In these circumstances, most researchers rely on key-based
search or browsing through proceedings of top conferences and journals to find
their related work. To ease this difficulty, we propose a Personalized Academic
Research Paper Recommendation System, which recommends related articles, for
each researcher, that may be interesting to her/him. In this paper, we first
introduce our web crawler to retrieve research papers from the web. Then, we
define similarity between two research papers based on the text similarity
between them. Finally, we propose our recommender system developed using
collaborative filtering methods. Our evaluation results demonstrate that our
system recommends good quality research papers.


title:
Classification of simple $W_n$-modules with finite-dimensional weight
  spaces

abstract:
  We classify all simple $W_n$-modules with finite-dimensional weight spaces.
Every such module is either of a highest weight type or is a quotient of a
module of tensor fields on a torus, which was conjectured by Eswara Rao. This
generalizes the classical result of Mathieu on simple weight modules for the
Virasoro algebra. In our proof of the classification we construct a functor
from the category of cuspidal $W_n$-modules to the category of $W_n$-modules
with a compatible action of the algebra of functions on a torus. We also
present a new identity for certain quadratic elements in the universal
enveloping algebra of $W_1$, which provides important information about
cuspidal $W_1$-modules.


title:
Stability Analysis of Flock and Mill rings for 2nd Order Models in
  Swarming

abstract:
  We study the linear stability of flock and mill ring solutions of two
individual based models for biological swarming. The individuals interact via a
nonlocal interaction potential that is repulsive in the short range and
attractive in the long range. We relate the instability of the flock rings with
the instability of the ring solution of the first order model. We observe that
repulsive-attractive interactions lead to new configurations for the flock
rings such as clustering and fattening formation. Finally, we numerically
explore mill patterns arising from this kind of interactions together with the
asymptotic speed of the system.


title:
Direct and inverse spectral problems for a class of non-selfadjoint band
  matrices

abstract:
  The spectral properties of a class of band matrices are investigated. The
reconstruction of matrices of this special class from given spectral data is
also studied. Necessary and sufficient conditions for that reconstruction are
found. The obtained results extend some results on the direct and inverse
spectral problems for periodic Jacobi matrices and for some non-self-adjoint
tridiagonal matrices.


title:
Boundaries for efficient use of electron vortex beams to measure
  magnetic properties

abstract:
  Development of experimental techniques for characterization of magnetic
properties at high spatial resolution is essential for progress in
miniaturization of magnetic devices, for example, in data storage media.
Inelastic scattering of electron vortex beams (EVB) was recently reported to
contain atom-specific magnetic information. We have developed a theoretical
description of inelastic scattering of EVB on crystals and performed
simulations for EVB of different diameters. We show that use of an EVB wider
than an interatomic distance does not provide any advantage over an ordinary
convergent beam without angular momentum. On the other hand, in the atomic
resolution limit, electron energy loss spectra measured by EVB are strongly
sensitive to the spin and orbital magnetic moments of studied matter, when
channeling through or very close to the atomic columns. Our results demonstrate
the boundaries for efficient use of EVB in measurement of magnetic properties.


title:
The dark side of the $\mu$: on multiple solutions to renormalisation
  group equations, and why the CMSSM is not necessarily being ruled out

abstract:
  When solving renormalisation group equations in a quantum field theory, one
often specifies the boundary conditions at multiple renormalisation scales,
such as the weak and grand-unified scales in a theory beyond the standard
model. A point in the parameter space of such a model is usually specified by
the values of couplings at these boundaries of the renormalisation group flow,
but there is no theorem guaranteeing that such a point has a unique solution to
the associated differential equations, and so there may exist multiple,
phenomenologically distinct solutions, all corresponding to the same point in
parameter space. We show that this is indeed the case in the constrained
minimal supersymmetric standard model (CMSSM), and we exhibit such solutions,
which cannot be obtained using out-of-the-box computer programs in the public
domain. Some of the multiple solutions we exhibit have CP-even lightest Higgs
mass predictions between 124 and 126 GeV. Without an exhaustive 11-dimensional
MSSM parameter scan per CMSSM parameter point to capture all of the multiple
solutions, CMSSM phenomenological analyses are incomplete.


title: Spin nematic states in antiferromagnets containing ferromagnetic bonds

abstract:
  The majority of recent works devoted to spin nematic phases deal with either
frustrated magnets or with those described by Hamiltonians with large
non-Heisenberg terms. We show in the present study that nonfrustrated
antiferromagnets (AFs) containing ferromagnetic (FM) bonds can show nematic
phases in a strong magnetic field. Among the particular spin systems discussed
are a ladder with FM rungs, two AF layers coupled ferromagnetically, a chain
containing alternating AF and FM bonds, and an AF anisotropic spin-1 chain.


title: On the Possibility of Superfast Charge Transfer in DNA

abstract:
  Numerous experiments on charge transfer in DNA yield a contradictory picture
of the transfer: on the one hand they suggest that it is a very slow process
and the charge is almost completely localized on one Watson-Crick pair, but on
the other hand they demonstrate that the charge can travel a very large
distance. To explain this contradiction we propose that superfast charge
transitions are possible between base pairs on individual DNA fragments
resulting in the establishment of a quasi-equilibrium charge distribution
during the time less than that of charge solvation. In other words, we
hypothesize these states irrespective of the nature of a mechanism responsible
for their establishment, whether it be a hopping mechanism, or a band
mechanism, or superexchange, or polaron transport, etc., leaving aside the
debates of which one is more advantageous. We discuss qualitative differences
between the charge transfer in a dry DNA and that in a solution. In a solution,
of great importance is the charge solvation which decreases the transfer rate
$10^7 - 10^8$ times as compared with a dry DNA. We consider the conditions
under which the superfast charge transfer in a DNA leading to quasi-equilibrium
distributions of polarons in a duplex is possible. Comparison of calculated
quasi-equilibrium distributions with the experiment testifies to the
possibility of superfast tunnel transitions of a hole in a DNA duplex in a
solution.


title:
Quadratic unipotent blocks in general linear, unitary and symplectic
  groups

abstract:
  An irreducible ordinary character of a finite reductive group is called
quadratic unipotent if it corresponds under Jordan decomposition to a
semisimple element $s$ in a dual group such that $s^2=1$. We prove that there
is a bijection between, on the one hand the set of quadratic unipotent
characters of $GL(n,q)$ or $U(n,q)$ for all $n \geq 0$ and on the other hand,
the set of quadratic unipotent characters of $Sp(2n,q)$ for all $n \geq 0$. We
then extend this correspondence to $\ell$-blocks for certain $\ell$ not
dividing $q$.


title:
A cross-intersection theorem for vector spaces based on semidefinite
  programming

abstract:
  Let $\mathscr{F}$ and $\mathscr{G}$ be families of $k$- and
$\ell$-dimensional subspaces, respectively, of a given $n$-dimensional vector
space over a finite field $\mathbb{F}_q$. Suppose that $x \cap y \ne 0$ for all
$x \in \mathscr{F}$ and $y \in \mathscr{G}$. By explicitly constructing optimal
feasible solutions to a semidefinite programming problem which is akin to
Lov\'{a}sz's theta function, we show that $|\mathscr{F}| |\mathscr{G}| \leq
{n-1 \brack k-1} {n-1 \brack \ell-1}$, provided that $n \geq 2k$ and $n \geq
2\ell$. The characterization of the extremal families is also established.


title: Spin nematic states in spin-1 antiferromagnets with easy-axis anisotropy

abstract:
  It is well known that spin nematic phases can appear in either frustrated
magnets or in those described by Hamiltonians with large exotic non-Heisenberg
terms like biquadratic exchange. We show in the present study that
non-frustrated spin-1 1D, 2D and 3D antiferromagnets with single-ion easy-axis
anisotropy can show nematic phases in strong magnetic field. For 1D case we
support our analytical results by numerical ones.


title: On triangles in K_r-minor free graphs

abstract:
  We study graphs where each edge adjacent to a vertex of small degree (7 and
9, respectively) belongs to many triangles (4 and 5, respectively) and show
that these graphs contain a complete graph (K_6 and K_7, respectively) as a
minor. The second case settles a problem of Nevo (Nevo, 2007). Morevover if
each edge of a graph belongs to 6 triangles then the graph contains a K_8-minor
or contains K_{2,2,2,2,2} as an induced subgraph. We then show applications of
these structural properties to stress freeness and coloration of graphs. In
particular, motivated by Hadwiger's conjecture, we prove that every K_7-minor
free graph is 8-colorable and every K_8-minor free graph is 10-colorable.


title:
Direct Measurement of Auger Electrons Emitted from a Semiconductor
  Light-Emitting Diode under Electrical Injection: Identification of the
  Dominant Mechanism for Efficiency Droop

abstract:
  We report on the unambiguous detection of Auger electrons by electron
emission spectroscopy from a cesiated InGaN/GaN light emitting diode (LED)
under electrical injection. Electron emission spectra were measured as a
function of the current injected in the device. The appearance of high energy
electron peaks simultaneously with an observed drop in electroluminescence
efficiency shows that hot carriers are being generated in the active region
(InGaN quantum wells) by an Auger process. A linear correlation was measured
between the high energy emitted electron current and the "droop current" - the
missing component of the injected current for light emission. We conclude that
the droop phenomenon in GaN LED originates from the excitation of Auger
processes.


title:
Impact of internal gravity waves on the rotation profile inside pre-main
  sequence low-mass stars

abstract:
  We study the impact of internal gravity waves (IGW), meridional circulation,
shear turbulence, and stellar contraction on the internal rotation profile and
surface velocity evolution of solar metallicity low-mass pre-main sequence
stars. We compute a grid of rotating stellar evolution models with masses
between 0.6 and 2.0Msun taking these processes into account for the transport
of angular momentum, as soon as the radiative core appears and assuming no more
disk-locking from that moment on.IGW generation along the PMS is computed
taking Reynolds-stress and buoyancy into account in the bulk of the stellar
convective envelope and convective core (when present). Redistribution of
angular momentum within the radiative layers accounts for damping of prograde
and retrograde IGW by thermal diffusivity and viscosity in corotation
resonance. Over the whole mass range considered, IGW are found to be
efficiently generated by the convective envelope and to slow down the stellar
core early on the PMS. In stars more massive than ~ 1.6Msun, IGW produced by
the convective core also contribute to angular momentum redistribution close to
the ZAMS. Overall, IGW are found to significantly change the internal rotation
profile of PMS low-mass stars.


title: Mendelian and Non-Mendelian Quadratic Operators

abstract:
  In this paper, we attempt to provide mathematical models of Mendelian and
Non-Mendelian inheritances of the bisexual population system having Fisher's
{\textbf{1:1}} principle. In our model, we always assume that distributions of
the same phenotype of female and male populations are equal. We study the
evolution of a Mendelian trait. As an application of a non-Mendelian
inheritance, we construct a quadratic stochastic operator that describes
transmission of {\textbf{ABO}} and Rh blood groups.


title: Multilevel Monte Carlo methods

abstract:
  The author's presentation of multilevel Monte Carlo path simulation at the
MCQMC 2006 conference stimulated a lot of research into multilevel Monte Carlo
methods. This paper reviews the progress since then, emphasising the
simplicity, flexibility and generality of the multilevel Monte Carlo approach.
It also offers a few original ideas and suggests areas for future research.


title:
A new method for constructing exact solutions to nonlinear delay partial
  differential equations

abstract:
  We propose a new method for constructing exact solutions to nonlinear delay
reaction--diffusion equations of the form $$ u_t=ku_{xx}+F(u,w), $$ where
$u=u(x,t)$, $w=u(x,t-\tau)$, and $\tau$ is the delay time. The method is based
on searching for solutions in the form $u=\sum^N_{n=1}\xi_n(x)\eta_n(t)$, where
the functions $\xi_n(x)$ and $\eta_n(t)$ are determined from additional
functional constraints (which are difference or functional equations) and the
original delay partial differential equation. All of the equations considered
contain one or two arbitrary functions of a single argument. We describe a
considerable number of new exact generalized separable solutions and a few more
complex solutions representing a nonlinear superposition of generalized
separable and traveling wave solutions. All solutions involve free parameters
(in some cases, infinitely many parameters) and so can be suitable for solving
certain problems and testing approximate analytical and numerical methods for
nonlinear delay PDEs. The results are extended to a wide class of nonlinear
partial differential-difference equations involving arbitrary linear
differential operators of any order with respect to the independent variables
$x$ and $t$ (in particular, this class includes the nonlinear delay
Klein--Gordon equation) as well as to some partial functional differential
equations with time-varying delay.


title:
Hot Brownian Carriers in the Langevin Picture: Application to a simple
  model for the Gunn Effect in GaAs

abstract:
  We consider a charged Brownian gas under the influence of external, static
and uniform electric and magnetic fields, immersed in a uniform bath
temperature. We obtain the solution for the associated Langevin equation, and
thereafter the evolution of the nonequilibrium temperature towards a
nonequilibrium (hot) steady state. We apply our results to a simple yet
relevant Brownian model for carrier transport in GaAs. We obtain a negative
differential conductivity regime (Gunn effect) and discuss and compare our
results with experimental results.


title: Making Math Searchable in Wikipedia

abstract:
  Wikipedia, the world largest encyclopedia contains a lot of knowledge that is
expressed as formulae exclusively. Unfortunately, this knowledge is currently
not fully accessible by intelligent information retrieval systems. This immense
body of knowledge is hidden form value-added services, such as search. In this
paper, we present our MathSearch implementation for Wikipedia that enables
users to perform a combined text and fully unlock the potential benefits.


title: The niche graphs of interval orders

abstract:
  The niche graph of a digraph $D$ is the (simple undirected) graph which has
the same vertex set as $D$ and has an edge between two distinct vertices $x$
and $y$ if and only if $N^+_D(x) \cap N^+_D(y) \neq \emptyset$ or $N^-_D(x)
\cap N^-_D(y) \neq \emptyset$, where $N^+_D(x)$ (resp. $N^-_D(x)$) is the set
of out-neighbors (resp. in-neighbors) of $x$ in $D$. A digraph $D=(V,A)$ is
called a semiorder (or a unit interval order) if there exist a real-valued
function $f:V \to \mathbb{R}$ on the set $V$ and a positive real number $\delta
\in \mathbb{R}$ such that $(x,y) \in A$ if and only if $f(x) > f(y) + \delta$.
A digraph $D=(V,A)$ is called an interval order if there exists an assignment
$J$ of a closed real interval $J(x) \subset \mathbb{R}$ to each vertex $x \in
V$ such that $(x,y) \in A$ if and only if $\min J(x) > \max J(y)$.
  S. -R. Kim and F. S. Roberts characterized the competition graphs of
semiorders and interval orders in 2002, and Y. Sano characterized the
competition-common enemy graphs of semiorders and interval orders in 2010. In
this note, we give characterizations of the niche graphs of semiorders and
interval orders.


title:
A Segmented, Enriched N-type Germanium Detector for Neutrinoless Double
  Beta-Decay Experiments

abstract:
  We present data characterizing the performance of the first segmented, N-type
Ge detector, isotopically enriched to 85% $^{76}$Ge. This detector, based on
the Ortec PT6x2 design and referred to as SEGA (Segmented, Enriched Germanium
Assembly), was developed as a possible prototype for neutrinoless double
beta-decay measurements by the {\sc Majorana} collaboration. We present some of
the general characteristics (including bias potential, efficiency, leakage
current, and integral cross-talk) for this detector in its temporary cryostat.
We also present an analysis of the resolution of the detector, and demonstrate
that for all but two segments there is at least one channel that reaches the
{\sc Majorana} resolution goal below 4 keV FWHM at 2039 keV, and all channels
are below 4.5 keV FWHM.


title:
Sloshing cold fronts in galaxy groups and their perturbing disk
  galaxies: an X-ray, Optical and Radio Case Study

abstract:
  We present a combined X-ray, optical, and radio analysis of the galaxy group
IC 1860 using the currently available Chandra and XMM data, literature
multi-object spectroscopy data and GMRT data. The Chandra and XMM imaging and
spectroscopy reveal two surface brightness discontinuities at 45 and 76 kpc
shown to be consistent with a pair of cold fronts. These features are
interpreted as due to sloshing of the central gas induced by an off-axis minor
merger with a perturber. This scenario is further supported by the presence of
a peculiar velocity of the central galaxy IC 1860 and the identification of a
possible perturber in the optically disturbed spiral galaxy IC 1859. The
identification of the perturber is consistent with the comparison with
numerical simulations of sloshing. The GMRT observation at 325 MHz shows faint,
extended radio emission contained within the inner cold front, as seen in some
galaxy clusters hosting diffuse radio mini-halos. However, unlike mini-halos,
no particle reacceleration is needed to explain the extended radio emission,
which is consistent with aged radio plasma redistributed by the sloshing. There
is strong analogy of the X-ray and optical phenomenology of the IC 1860 group
with two other groups, NGC 5044 and NGC 5846, showing cold fronts. The evidence
presented in this paper is among the strongest supporting the currently favored
model of cold-front formation in relaxed objects and establishes the group
scale as a chief environment to study this phenomenon.


title: Local Backbones

abstract:
  A backbone of a propositional CNF formula is a variable whose truth value is
the same in every truth assignment that satisfies the formula. The notion of
backbones for CNF formulas has been studied in various contexts. In this paper,
we introduce local variants of backbones, and study the computational
complexity of detecting them. In particular, we consider k-backbones, which are
backbones for sub-formulas consisting of at most k clauses, and iterative
k-backbones, which are backbones that result after repeated instantiations of
k-backbones. We determine the parameterized complexity of deciding whether a
variable is a k-backbone or an iterative k-backbone for various restricted
formula classes, including Horn, definite Horn, and Krom. We also present some
first empirical results regarding backbones for CNF-Satisfiability (SAT). The
empirical results we obtain show that a large fraction of the backbones of
structured SAT instances are local, in contrast to random instances, which
appear to have few local backbones.


title: A Mesonic Analog of the Deuteron

abstract:
  Using the LAMP model for nuclear quark structure, we calculate the binding
energy and quark structure of a $B$ meson merging with a $D$ meson. The
larger-than-nucleon masses of the two heavy quarks allow for a more reliable
application of the Born-Oppenheimer-like approximation of the LAMP. With the
absence of quark-level Pauli Exclusion Principle repulsive effects, the
appearance of a bound state is unsurprising. Our variational calculation shows
that the molecular, deuteron-like state structure changes rather abruptly, as
the separation between the two mesons decreases, at a separation of about 0.45
fm, into a four-quark bound state, although one maintaining an internal
structure rather than that of a four-quark bag. Unlike the deuteron, pion
exchange does not provide any contribution to the $\approx 150$ MeV binding.


title:
Re-determining the Galactic spiral density wave parameters from data on
  masers with trigonometric parallaxes

abstract:
  The parameters of the Galactic spiral wave are re-determined using a modified
periodogram (spectral) analysis of the galactocentric radial velocities of 58
masers with known trigonometric parallaxes, proper motions, and line-of-site
velocities. The masers span a wide range of galactocentric distances,
$3<$R$<14$ kpc, which, combined with a large scatter of position angles
$\theta$ of these objects in the Galactic plane XY, required an accurate
account of logarithmic dependence of spiral-wave perturbations on both
galactocentric distance and position angle. A periodic signal was detected
corresponding to the spiral density wave with the wavelength $\lambda=2.4 \pm
0.4$ kpc, peak velocity of wave perturbations $f_R=7.5 \pm 1.5$ km s$^{-1}$,
the phase of the Sun in the density wave $\chi_\odot=-160 \pm 15^\circ$, and
the pitch angle of $-5.5 \pm 1^\circ$.


title: Kinematics of nearby OB3 stars with interstellar CaII line distances

abstract:
  We tested the distances derived from the equivalent widths of interstellar
CaII spectral lines by Megier et al. 2009. To this end, we used a sample of
nearby 126 young OB3 stars ($r<1$ kpc) with known proper motions and
line-of-site velocities. It is shown that these stars are tightly bounded with
the Gould Belt structure. Most part of this sample (about 100 stars) show the
same kinematics as the sample of distant OB3 stars. Their galactocentric radial
velocities are in good agreement with the following spiral density wave
parameters: amplitude of radial perturbations $f_R\approx$12 km/s, wavelength
$\lambda\approx2.3$ kpc and phase of the Sun in spiral wave
$\chi_\odot\approx-90^\circ$. But we revealed 20 stars with absolutely unusual
kinematical features. Their galactocentric radial velocities show a wave,
biased on $\approx180^\circ$ with respect to the wave, found from the whole
sample. The idea of superposition of two spiral patterns seems to be probable.


title: Ambiguities in the Seiberg-Witten Map and Emergent Gravity

abstract:
  The theta expansion of the Seiberg-Witten map has ambiguities which can be
removed by a gauge transformation and/or a field redefinition. In the context
of emergent gravity such a field redefinition changes the emerging metric and
requires the presence of non-minimal gravitational couplings. It also requires
that a real scalar field becomes a scalar density and allows the introduction
of a potential. We also find that the potential can have only one term and that
a quartic interaction is not allowed. Even though the metric depends on the
ambiguity we show that the dispersion relation does not present any sign of it.
A proposal for an exact Seiberg-Witten map is used to derive the full metric
going beyond the linearized limit.


title:
Generation of Axion-Like Couplings via Quantum Corrections in a Lorentz
  Violating Background

abstract:
  Light pseudoscalars, or axion like particles (ALPs), are much studied due to
their potential relevance to the fields of particle physics, astrophysics and
cosmology. The most relevant coupling of ALPs from the viewpoint of current
experimental searches is to the photon: in this work, we study the generation
of this coupling as an effect of quantum corrections, originated from an
underlying Lorentz violating background. Most interestingly, we show that the
interaction so generated turns out to be Lorentz invariant, thus mimicking the
standard ALPs coupling to the photon that is considered in the experiments.
This consideration implies that violations of spacetime symmetries, much
studied as possible consequences of physics in very high energy scales, might
infiltrate in other realms of physics in unsuspected ways. Additionally, we
conjecture that a similar mechanism can also generate Lorentz invariant
couplings involving scalar particles and photons, playing a possible role in
the phenomenology of Higgs bosons.


title: An Introduction to Quantum Programming in Quipper

abstract:
  Quipper is a recently developed programming language for expressing quantum
computations. This paper gives a brief tutorial introduction to the language,
through a demonstration of how to make use of some of its key features. We
illustrate many of Quipper's language features by developing a few well known
examples of Quantum computation, including quantum teleportation, the quantum
Fourier transform, and a quantum circuit for addition.


title:
Inferring evolutionary histories of pathway regulation from
  transcriptional profiling data

abstract:
  One of the outstanding challenges in comparative genomics is to interpret the
evolutionary importance of regulatory variation between species. Rigorous
molecular evolution-based methods to infer evidence for natural selection from
expression data are at a premium in the field, and to date, phylogenetic
approaches have not been well-suited to address the question in the small sets
of taxa profiled in standard surveys of gene expression. We have developed a
strategy to infer evolutionary histories from expression profiles by analyzing
suites of genes of common function. In a manner conceptually similar to
molecular evolution models in which the evolutionary rates of DNA sequence at
multiple loci follow a gamma distribution, we modeled expression of the genes
of an \emph{a priori}-defined pathway with rates drawn from an inverse gamma
distribution. We then developed a fitting strategy to infer the parameters of
this distribution from expression measurements, and to identify gene groups
whose expression patterns were consistent with evolutionary constraint or rapid
evolution in particular species. Simulations confirmed the power and accuracy
of our inference method. As an experimental testbed for our approach, we
generated and analyzed transcriptional profiles of four \emph{Saccharomyces}
yeasts. The results revealed pathways with signatures of constrained and
accelerated regulatory evolution in individual yeasts and across the phylogeny,
highlighting the prevalence of pathway-level expression change during the
divergence of yeast species. We anticipate that our pathway-based phylogenetic
approach will be of broad utility in the search to understand the evolutionary
relevance of regulatory change.


title: Analysis of the two-regime method on square meshes

abstract:
  The two-regime method (TRM) has been recently developed for optimizing
stochastic reaction-diffusion simulations. It is a multiscale (hybrid)
algorithm which uses stochastic reaction-diffusion models with different levels
of detail in different parts of the computational domain. The coupling
condition on the interface between different modelling regimes of the TRM was
previously derived for one-dimensional models. In this paper, the TRM is
generalized to higher dimensional reaction-diffusion systems. Coupling Brownian
dynamics models with compartment-based models on regular (square)
two-dimensional lattices is studied in detail. In this case, the interface
between different modelling regimes contain either flat parts or right-angled
corners. Both cases are studied in the paper. For flat interfaces, it is shown
that the one-dimensional theory can be used along the line perpendicular to the
TRM interface. In the direction tangential to the interface, two choices of the
TRM parameters are presented. Their applicability depends on the compartment
size and the time step used in the molecular-based regime. The two-dimensional
generalization of the TRM is also discussed in the case of corners.


title: On-Orbit Degradation of Solar Instruments

abstract:
  We present the lessons learned about the degradation observed in several
space solar missions, based on contributions at the Workshop about On-Orbit
Degradation of Solar and Space Weather Instruments that took place at the Solar
Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on
3 May 2012. The aim of this workshop was to open discussions related to the
degradation observed in Sun-observing instruments exposed to the effects of the
space environment. This article summarizes the various lessons learned and
offers recommendations to reduce or correct expected degradation with the goal
of increasing the useful lifespan of future and ongoing space missions.


title:
Disturbances in the U.S. electric grid associated with geomagnetic
  activity

abstract:
  Large solar explosions are responsible for space weather that can impact
technological infrastructure on and around Earth. Here, we apply a
retrospective cohort exposure analysis to quantify the impacts of geomagnetic
activity on the U.S. electric power grid for the period from 1992 through 2010.
We find, with more than 3-sigma significance, that approximately 4% of the
disturbances in the U.S. power grid reported to the U.S. Department of Energy
are attributable to strong geomagnetic activity and its associated
geomagnetically induced currents.


title:
Quantum Private Information Retrieval has linear communication
  complexity

abstract:
  In Private Information Retrieval (PIR), a client queries an n-bit database in
order to retrieve an entry of her choice, while maintaining privacy of her
query value. Chor, Goldreich, Kushilevitz, and Sudan showed that, in the
information-theoretical setting, a linear amount of communication is required
for classical PIR protocols (and thus that the trivial protocol is optimal).
This linear lower bound was shown by Nayak to hold also in the quantum setting.
Here, we extend Nayak's result by considering approximate privacy, and
requiring security only against "specious" adversaries, which are, in analogy
to classical honest-but-curious adversaries, the weakest reasonable quantum
adversaries. We show that, even in this weakened scenario, Quantum Private
Information Retrieval (QPIR) requires n qubits of communication. From this
follows that Le Gall's recent QPIR protocol with sublinear communication
complexity is not information-theoretically private, against the weakest
reasonable cryptographic adversary.


title: Operator evolution for ab initio electric dipole transitions of 4He

abstract:
  A goal of nuclear theory is to make quantitative predictions of low-energy
nuclear observables starting from accurate microscopic internucleon forces. A
major element of such an effort is applying unitary transformations to soften
the nuclear Hamiltonian and hence accelerate the convergence of ab initio
calculations as a function of the model space size. The consistent simultaneous
transformation of external operators, however, has been overlooked in
applications of the theory, particularly for nonscalar transitions. We study
the evolution of the electric dipole operator in the framework of the
similarity renormalization group method and apply the renormalized matrix
elements to the calculation of the 4He total photoabsorption cross section and
electric dipole polarizability. All observables are calculated within the ab
initio no-core shell model. We find that, although seemingly small, the effects
of evolved operators on the photoabsorption cross section are comparable in
magnitude to the correction produced by including the chiral three-nucleon
force and cannot be neglected.


title: Quasitriangular Hopf algebras, braid groups and quantum entanglement

abstract:
  The aim of the paper is to provide an method to obtain representations of the
braid group through a set of quasitriangular Hopf algebras. In particular,
these algebras may be derived from group algebras of cyclic groups with
additional algebraic structures. In this context, by using the flip operator,
it is possible to construct R-matrices that can be regarded as quantum logic
gates capable of preserving quantum entanglement.


title: Low Variance at large scales of WMAP 9 year data

abstract:
  We use an optimal estimator to study the variance of the WMAP 9 CMB field at
low resolution, in both temperature and polarization. Employing realistic Monte
Carlo simulation, we find statistically significant deviations from the
$\Lambda$CDM model in several sky cuts for the temperature field. For the
considered masks in this analysis, which cover at least the 54% of the sky, the
WMAP 9 CMB sky and $\Lambda$CDM are incompatible at $ \ge 99.94%$ C.L. at large
angles ($>5^\circ$). We find instead no anomaly in polarization. As a byproduct
of our analysis, we present new, optimal estimates of the WMAP 9 CMB angular
power spectra from the WMAP 9 year data at low resolution.


title: Keepers of the Double Stars

abstract:
  Astronomers have long tracked double stars in efforts to find those that are
gravitationally-bound binaries and then to determine their orbits. Early
catalogues by the Herschels, Struves, and others began with their own
discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley
Burnham published a massive double star catalogue containing data from many
observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant
Aitken produced a much larger catalogue in 1932 and coordinated with Robert
Innes of Johannesburg, who catalogued the southern systems. Aitken maintained
and expanded Burnham's records of observations on handwritten file cards, and
eventually turned them over to the Lick Observatory, where astrometrist
Hamilton Jeffers further expanded the collection and put all the observations
on punched cards. With the aid of Frances M. "Rete" Greeby he made two
catalogues: an Index Catalogue with basic data about each star, and a complete
catalogue of observations, with one observation per punched card. He enlisted
Willem van den Bos of Johannesburg to add southern stars, and together they
published the Index Catalogue of Visual Double Stars, 1961.0. As Jeffers
approached retirement he became greatly concerned about the disposition of the
catalogues. He wanted to be replaced by another "double star man," but Lick
Director Albert E. Whitford had the new 120-inch reflector, the world's second
largest telescope, and he wanted to pursue modern astrophysics instead. Jeffers
was vociferously opposed to turning over the card files to another institution,
and especially against their coming under the control of Kaj Strand of the
United States Naval Observatory. The USNO got the files and has maintained the
records ever since, first under Charles Worley, and, since 1997, under Brian
Mason. Now called the Washington Double Star Catalog, it is online.


title:
Harmonic and Dirac oscillators in a (2+1)-dimensional noncommutative
  space

abstract:
  We study the Harmonic and Dirac Oscillator problem extended to a
three-dimensional noncom- mutative space where the noncommutativity is induced
by a shift of the dynamical variables with generators of SL(2;R) in a unitary
irreducible representation. The Hilbert space gets the structure of a direct
product with the representation space as a factor, where there exist operators
which realize the algebra of Lorentz transformations. The spectrum of these
models are considered in perturbation theory, both for small and large
noncommutativity parameters, finding no constraints between coordinates and
momenta noncom- mutativity parameters. Since the representation space of the
unitary irreducible representations SL(2;R) can be realized in terms of spaces
of square-integrable functions, we conclude that these models are equivalent to
quantum mechanical models of particles living in a space with an additional
compact dimension.
  PACS: 03.65.-w; 11.30.Cp; 02.40.Gh


title: Inertial Range Scaling in Rotations of Long Rods in Turbulence

abstract:
  We measure the rotational statistics of neutrally buoyant rods with lengths
$2.8 < l/\eta <72.9 $ in turbulence. For particles with length in the inertial
range, we derive a scaling relationship for the mean square rotation rate, $<
\dot{p}_i \dot{p}_i > \propto l^{-4/3}$ and show that measurements approach
this scaling. Deviations from the proposed scaling are explained as the effect
of dissipation range scales. The correlation time of the Lagrangian
autocorrelation of rod rotation rate scales as the turn over time of eddies of
the size of the rod. Measuring rotational dynamics of single long rods provides
a new way to access the spatial structure of the flow at different length
scales.


title: Large deviations for systems with non-uniform structure

abstract:
  We use a weak Gibbs property and a weak form of specification to derive
level-2 large deviations principles for symbolic systems equipped with a large
class of reference measures. This has applications to a broad class of symbolic
systems, including $\beta$-shifts, $S$-gap shifts, and their factors. A crucial
step in our approach is to prove a `horseshoe theorem' for these systems.


title: A SAT Approach to Clique-Width

abstract:
  Clique-width is a graph invariant that has been widely studied in
combinatorics and computer science. However, computing the clique-width of a
graph is an intricate problem, the exact clique-width is not known even for
very small graphs. We present a new method for computing the clique-width of
graphs based on an encoding to propositional satisfiability (SAT) which is then
evaluated by a SAT solver. Our encoding is based on a reformulation of
clique-width in terms of partitions that utilizes an efficient encoding of
cardinality constraints. Our SAT-based method is the first to discover the
exact clique-width of various small graphs, including famous graphs from the
literature as well as random graphs of various density. With our method we
determined the smallest graphs that require a small pre-described clique-width.


title: Biharmonic curves in Finsler spaces

abstract:
  Biharmonic curves are a generalization of geodesics, with applications in
elasticity theory and various branches of computer science. The paper proposes
a first study of biharmonic curves in spaces with Finslerian geometry, covering
the following topics: a deduction of their equations, existence of non-geodesic
biharmonic curves for some classes of Finsler spaces and specific properties.
We prove, for instance, that geodesic curvature is constant along Finslerian
biharmonic curves. Integration of the biharmonic equation is presented for two
concrete Finsler metrics.


title: Supernova interaction with dense mass loss

abstract:
  Supernovae of Type IIn (narrow line) appear to be explosions that had strong
mass loss before the event, so that the optical luminosity is powered by the
circumstellar interaction. If the mass loss region has an optical depth
$>c/v_s$, where $v_s$ is the shock velocity, the shock breakout occurs in the
mass loss region and a significant fraction of the explosion energy can be
radiated. The emission from the superluminous SN 2006gy and the normal
luminosity SN 2011ht can plausibly be attributed to shock breakout in a wind,
with SN 2011ht being a low energy event. Superluminous supernovae of Type I may
derive their luminosity from interaction with a mass loss region of limited
extent. However, the distinctive temperature increase to maximum luminosity has
not been clearly observed in Type I events. Suggested mechanisms for the strong
mass loss include pulsational pair instability, gravity-waves generated by
instabilities in late burning phases, and binary effects.


title: Screening in multilayer graphene

abstract:
  In this article we study the static polarization in ABC-stacked multilayer
graphene. Since the density of states diverges for these systems if the number
of layers exceeds three, screening effects are expected to be important. In the
random phase approximation, screening can be included through the polarization.
We derive an analytical integral expression for the polarization in both the
full-band model and an effective two-band model. Numerical evaluation of these
integrals are very time consuming in the full-band model. Hence, for
ABC-stacked trilayer graphene, we use the two-band model to calculate the low
momentum part of the polarization. The results for the two-band model are
universal, i.e. independent of doping. The high momentum part is linear and is
determined by calculating two points, such that we can determine the slope. For
ABC stacked trilayer graphene, the slope is given by three times the monolayer
value. We compare our results to previous ones in the literature and discuss
the similarities and discrepancies. Our results can be used to include
screening in ABC-stacked multilayer systems in a way that all the
characteristics of the polarization function are included. The numerical
results for the polarization of trilayer graphene are used to sketch the
screened potential.


title: Quasihomogeneous analytic affine connections on surfaces

abstract:
  We classify torsion-free real-analytic affine connections on compact oriented
real-analytic surfaces which are locally homogeneous on a nontrivial open set,
without being locally homogeneous on all of the surface. In particular, we
prove that such connections exist. This classification relies in a local result
that classifies germs of torsion-free real-analytic affine connections on a
neighborhood of the origin in the plane which are quasihomogeneous, in the
sense that they are locally homogeneous on an open set containing the origin in
its closure, but not locally homogeneous in the neighborhood of the origin.


title: Bosonic transport through a chain of quantum dots

abstract:
  The particle transport through a chain of quantum dots coupled to two bosonic
reservoirs is studied. For the case of reservoirs of non-interacting bosonic
particles, we derive an exact set of stochastic differential equations, whose
memory kernels and driving noise are characterised entirely by the properties
of the reservoirs. Going to the Markovian limit an analytically solvable case
is presented. The effect of interparticle interactions on the transient
behaviour of the system, when both reservoirs are instantaneously coupled to an
empty chain of quantum dots, is approximated by a semiclassical method, known
as the Truncated Wigner approximation. The steady-state particle flow through
the chain and the mean particle occupations are explained via the spectral
properties of the interacting system.


title:
Optimal Stochastic Strongly Convex Optimization with a Logarithmic
  Number of Projections

abstract:
  We consider stochastic strongly convex optimization with a complex inequality
constraint. This complex inequality constraint may lead to computationally
expensive projections in algorithmic iterations of the stochastic gradient
descent~(SGD) methods. To reduce the computation costs pertaining to the
projections, we propose an Epoch-Projection Stochastic Gradient
Descent~(Epro-SGD) method. The proposed Epro-SGD method consists of a sequence
of epochs; it applies SGD to an augmented objective function at each iteration
within the epoch, and then performs a projection at the end of each epoch.
Given a strongly convex optimization and for a total number of $T$ iterations,
Epro-SGD requires only $\log(T)$ projections, and meanwhile attains an optimal
convergence rate of $O(1/T)$, both in expectation and with a high probability.
To exploit the structure of the optimization problem, we propose a proximal
variant of Epro-SGD, namely Epro-ORDA, based on the optimal regularized dual
averaging method. We apply the proposed methods on real-world applications; the
empirical results demonstrate the effectiveness of our methods.


title:
Planets around stars in young nearby associations *** radial Velocity
  searches: a feasibility study, and first results

abstract:
  Stars in young nearby associations are the only targets allowing giant planet
searches at all separations in the near future, by coupling indirect techniques
such as radial velocity and deep imaging. These stars are first priorities
targets for the forthcoming planets imagers on 10-m class telescopes. Young
stars rotate more rapidly and are more active than their older counterparts.
Both effects can limit the capability to detect planets using RV. We wish to
explore the planet detection capabilities of a representative sample of stars
in close and young associations with radial velocity data and explore the
complementarity between this technique and direct imaging. We observed 26 such
targets with spectral types from A to K and ages from


title: Two-dimensional solutions for Born-Infeld fields

abstract:
  The non-linear second order Born-Infeld equation is reduced to a simpler
first order complex equation, which can be trivially solved for the coordinates
as functions of the field. Each solution is determined by the choice of a
holomorphic function subjected to boundary conditions. The explanation of the
method is accompanied by applications to Born-Infeld electrostatics,
magnetostatics and wave propagation.


title: Analysing Mood Patterns in the United Kingdom through Twitter Content

abstract:
  Social Media offer a vast amount of geo-located and time-stamped textual
content directly generated by people. This information can be analysed to
obtain insights about the general state of a large population of users and to
address scientific questions from a diversity of disciplines. In this work, we
estimate temporal patterns of mood variation through the use of emotionally
loaded words contained in Twitter messages, possibly reflecting underlying
circadian and seasonal rhythms in the mood of the users. We present a method
for computing mood scores from text using affective word taxonomies, and apply
it to millions of tweets collected in the United Kingdom during the seasons of
summer and winter. Our analysis results in the detection of strong and
statistically significant circadian patterns for all the investigated mood
types. Seasonal variation does not seem to register any important divergence in
the signals, but a periodic oscillation within a 24-hour period is identified
for each mood type. The main common characteristic for all emotions is their
mid-morning peak, however their mood score patterns differ in the evenings.


title:
Magnetic field strength distribution of magnetic bright points inferred
  from filtergrams and spectro-polarimetric data

abstract:
  Small scale magnetic fields can be observed on the Sun in G-band filtergrams
as MBPs (magnetic bright points) or identified in spectro-polarimetric
measurements due to enhanced signals of Stokes profiles. These magnetic fields
and their dynamics play a crucial role in understanding the coronal heating
problem and also in surface dynamo models. MBPs can theoretically be described
to evolve out of a patch of a solar photospheric magnetic field with values
below the equipartition field strength by the so-called convective collapse
model. After the collapse, the magnetic field of MBPs reaches a higher stable
magnetic field level. The magnetic field strength distribution of small scale
magnetic fields as seen by MBPs is inferred. Furthermore, we want to test the
model of convective collapse and the theoretically predicted stable value of
about 1300 G. We used four different data sets of high-resolution Hinode/SOT
observations that were recorded simultaneously with the broadband filter device
(G-band, Ca II-H) and the spectro-polarimeter. To derive the magnetic field
strength distribution of these small scale features, the spectropolarimeter
(SP) data sets were treated by the Merlin inversion code. The four data sets
comprise different solar surface types: active regions (a sunspot group and a
region with pores), as well as quiet Sun. In all four cases the obtained
magnetic field strength distribution of MBPs is similar and shows peaks around
1300 G. This agrees well with the theoretical prediction of the convective
collapse model. The resulting magnetic field strength distribution can be
fitted in each case by a model consisting of log-normal components. The
important parameters, such as geometrical mean value and multiplicative
standard deviation, are similar in all data sets, only the relative weighting
of the components is different.


title:
On Modeling Geometric Joint Sink Mobility with Delay-Tolerant
  Cluster-less Wireless Sensor Networks

abstract:
  Moving Sink (MS) in Wireless Sensor Networks (WSNs) has appeared as a
blessing because it collects data directly from the nodes where the concept of
relay nodes is becomes obsolete. There are, however, a few challenges to be
taken care of, like data delay tolerance and trajectory of MS which is NP-hard.
In our proposed scheme, we divide the square field in small squares. Middle
point of the partitioned area is the sojourn location of the sink, and nodes
around MS are in its transmission range, which send directly the sensed data in
a delay-tolerant fashion. Two sinks are moving simultaneously; one inside and
having four sojourn locations and other in outer trajectory having twelve
sojourn locations. Introduction of the joint mobility enhances network life and
ultimately throughput. As the MS comes under the NP-hard problem, we convert it
into a geometric problem and define it as, Geometric Sink Movement (GSM). A set
of linear programming equations has also been given in support of GSM which
prolongs network life time.


title:
Multiplicity of solutions to the Yamabe problem on collapsing Riemannian
  submersions

abstract:
  Let g_t be a family of constant scalar curvature metrics on the total space
of a Riemannian submersion obtained by shrinking the fibers of an original
metric g, so that the submersion collapses as t approaches 0 (i.e., the total
space converges to the base in the Gromov-Hausdorff sense). We prove that,
under certain conditions, there are at least 3 unit volume constant scalar
curvature metrics in the conformal class [g_t] for infinitely many t's
accumulating at 0. This holds, e.g., for homogeneous metrics g_t obtained via
Cheeger deformation of homogeneous fibrations with fibers of positive scalar
curvature.


title:
Sets of uniqueness for uniform limits of polynomials in several complex
  variables

abstract:
  We investigate the sets of uniform limits $A(\bar{B}_n)$, $A(\bar{D}^I)$ of
polynomials on the closed unit ball $\bar{B}_n$ of $\mathbb{C}^n$ and on the
cartesian product $\bar{D}^I$ where $I$ is an arbitrary set and $\bar{D}$ is
the closed unit disc in $\mathbb{C}$. We introduce the notion of set of
uniqueness for $A(\bar{D}^I)$ (respectively for $A(\bar{B}_n)$) for compact
subsets $K$ of $T^I$ (respectively of $\partial \bar{B}_n$) where $T=\partial
D$ is the unit circle. Our main result is that if $K$ has positive measure then
$K$ is a set of uniqueness. The converse does not hold. Finally, we do a
similar study when the uniform convergence is not meant with respect to the
usual Euclidean metric in $\mathbb{C}$, but with respect to the chordal metric
$\chi$ on $\mathbb{C} \cup \{\infty \}$.


title:
Correlation functions of the integrable isotropic spin-1 chain:
  algebraic expressions for arbitrary temperature

abstract:
  We derive algebraic formulas for the density matrices of finite segments of
the integrable su(2) isotropic spin-1 chain in the thermodynamic limit. We give
explicit results for the 2 and 3 site cases for arbitrary temperature T and
zero field. In the zero temperature limit the correlation functions are given
in elementary form in terms of Riemann's zeta function at even integer
arguments.


title: Numerical modeling of non-woven fiber mats

abstract:
  Numerical simulations on non-woven-fibrous, porous structures were performed
to determine material design space for energy storage device (battery and
ultracapacitor) separators.


title: An Embedded Boundary Method for Two Phase Incompressible Flow

abstract:
  We develop an embedded boundary method (EBM) to solve the two-phase
incompressible flow with piecewise constant density. The front tracking method
is used to track the interface. The fractional step methods are used to solve
the incompressible Navier-Stokes equations while the EBM is used in the
projection step to solve an elliptic interface problem for the pressure with a
jump equal to the surface tension force across the interface. Several examples
are used to verify the accuracy of the method.


title:
Extension of Pierce model to multiple transmission lines interacting
  with an electron beam

abstract:
  A possible route towards achieving high power microwave (HPM) devices is
through the use of novel slow-wave structures, represented by multiple coupled
transmission lines (MTLs), and whose behavior when coupled to electron beams
has not been sufficiently explored. We present the extension of the
one-dimensional linearized Pierce theory to MTLs coupled to a single electron
beam. We develop multiple formalisms to calculate the k-{\omega} dispersion
relation of the system and find that the existence of a growing wave solution
is always guaranteed if the electron propagation constant is larger than or
equal to the largest propagation constant of the MTL system. We verify our
findings with illustrative examples which bring to light unique properties of
the system in which growing waves were found to exist within finite bands of
the electron propagation constant and also present possible means to improve
the gain. By treating the beam-MTL interaction as distributed dependent current
generators in the MTL, we derive relations characterizing the power flux and
energy exchange between the beam and the MTLs. For the growing wave, we show
that the beam always behaves as an energy source causing power flux along the
transmission lines. The theory developed in this paper is the basis for the
possible use of degenerate band-edges in periodic MTL systems for HPM
amplifiers.


title: Dielectric mixtures: Importance and theoretical approaches

abstract:
  Physics of dielectric mixtures are presented to stimulate discussion and to
provide information on the recent advances in this topic.


title: Coronal Thick Target Hard X Ray Emissions and Radio Emissions

abstract:
  Recently a distinctive class of hard X ray (HXR) sources located in the
corona was found, which implies that the collisionally thick target model
(CTTM) applies even to the corona. We investigated whether this idea can
independently be verified by microwave radiations that have been known as the
best companion to HXRs. The study is made for the GOES M2.3 class flare
occurred on 2002 September 9 that were observed by the Reuven Ramaty High
Energy Solar Spectroscopic Imager (RHESSI) and the Owens Valley Solar Array
(OVSA). Interpreting the observed energy dependent variation of HXR source size
under the CTTM the coronal density should be as high as $5\times 10^{11}$
cm$^{-3}$ over the distance up to 12$"$. To explain the cut-off feature of
microwave spectrum at 3 GHz, we however, need density no higher than $1\times
10^{11}$ cm$^{-3}$. Additional constraints need to be placed on temperature and
magnetic field of the coronal source in order to reproduce the microwave
spectrum as a whole. Firstly, a spectral feature called the Razin suppression
requires the magnetic field in a range of 250--350 gauss along with high
viewing angles around 75$^{\rm o}$. Secondly, to avoid excess fluxes at high
frequencies due to the free-free emission that were not observed, we need a
high temperature $\geq2\times 10^7$ K. These two microwave spectral features,
Razzin suppression and free-free emissions, become more significant at regions
of high thermal plasma density and are essential for validating and for
determining additional parameters for the coronal HXR sources.


title: Upper and Lower Bounds for Weak Backdoor Set Detection

abstract:
  We obtain upper and lower bounds for running times of exponential time
algorithms for the detection of weak backdoor sets of 3CNF formulas,
considering various base classes. These results include (omitting polynomial
factors), (i) a 4.54^k algorithm to detect whether there is a weak backdoor set
of at most k variables into the class of Horn formulas; (ii) a 2.27^k algorithm
to detect whether there is a weak backdoor set of at most k variables into the
class of Krom formulas. These bounds improve an earlier known bound of 6^k. We
also prove a 2^k lower bound for these problems, subject to the Strong
Exponential Time Hypothesis.


title:
The Dynamics of Sex Ratio Evolution: From the Gene Perspective to
  Multilevel Selection

abstract:
  The new dynamical game theoretic model of sex ratio evolution emphasizes the
role of males as passive carriers of sex ratio genes. This shows inconsistency
between population genetic models of sex ratio evolution and classical
strategic models. In this work a novel technique of change of coordinates will
be applied to the new model. This will reveal new aspects of the modelled
phenomenon which cannot be shown or proven in the original formulation. The
underlying goal is to describe the dynamics of selection of particular genes in
the entire population, instead of in the same sex subpopulation, as in the
previous paper and earlier population genetics approaches. This allows for
analytical derivation of the unbiased strategic model from the model with
rigorous non-simplified genetics. In effect, an alternative system of
replicator equations is derived. It contains two subsystems: the first
describes changes in gene frequencies (this is an alternative unbiased
formalization of the Fisher-Dusing argument), whereas the second describes
changes in the sex ratios in subpopulations of carriers of genes for each
strategy. An intriguing analytical result of this work is that fitness of a
gene depends on the current sex ratio in the subpopulation of its carriers, not
on the encoded individual strategy. Thus, the argument of the gene fitness
function is not constant but is determined by the trajectory of the sex ratio
among carriers of that gene. This aspect of the modelled phenomenon cannot be
revealed by the static analysis. Dynamics of the sex ratio among gene carriers
is driven by a dynamic "tug of war" between female carriers expressing the
encoded strategic trait value and random partners of male carriers expressing
the average population strategy (a primary sex ratio). This mechanism can be
called "double level selection". Therefore, gene interest perspective leads to
multi-level selection.


title:
Engineering Ising-XY spin models in a triangular lattice via tunable
  artificial gauge fields

abstract:
  Emulation of gauge fields for ultracold atoms provides access to a class of
exotic states arising in strong magnetic fields. Here we report on the
experimental realisation of tunable staggered gauge fields in a periodically
driven triangular lattice. For maximal staggered magnetic fluxes, the doubly
degenerate superfluid ground state breaks both a discrete Z2 (Ising) symmetry
and a continuous U(1) symmetry. By measuring an Ising order parameter, we
observe a thermally driven phase transition from an ordered antiferromagnetic
to an unordered paramagnetic state and textbook-like magnetisation curves. Both
the experimental and theoretical analysis of the coherence properties of the
ultracold gas demonstrate the strong influence of the Z2 symmetry onto the
condensed phase.


title: Vortex Filament Equation for a Regular Polygon

abstract:
  In this paper, we study the evolution of the vortex filament equation (VFE),
$$\mathbf X_t = \mathbf X_s \wedge \mathbf X_{ss},$$ with $\mathbf X(s, 0)$
being a regular planar polygon. Using algebraic techniques, supported by full
numerical simulations, we give strong evidence that $\mathbf X(s, t)$ is also a
polygon at any rational time; moreover, it can be fully characterized, up to a
rigid movement, by a generalized quadratic Gau{\ss} sum.
  We also study the fractal behavior of $\mathbf X(0, t)$, relating it with the
so-called Riemann's non-differentiable function, that was proved by Jaffard to
be a multifractal.


title: Velocity requirements for causality violation

abstract:
  We re-examine the "Regge-Tolman paradox" with reference to some recent
experimental results. It is straightforward to find a formula for the velocity
v of the moving system required to produce causality violation. This formula
typically yields a velocity very close to the speed of light (for instance, v/c
> 0.97 for X-shaped microwaves), which raises some doubts about the real
physical observability of the violations. We then compute the velocity
requirement introducing a delay between the reception of the primary signal and
the emission of the secondary. It turns out that in principle for any delay it
is possible to find moving observers able to produce active causal violation.
This is mathematically due to the singularity of the Lorentz transformations
for beta to 1. For a realistic delay due to the propagation of a luminal
precursor, we find that causality violations in the reported experiments are
still more unlikely (v/c > 0.989), and even in the hypothesis that the
superluminal propagation velocity goes to infinity, the velocity requirement is
bounded by v/c > 0.62. We also prove that if two macroscopic bodies exchange
energy and momentum through superluminal signals, then the swap of signal
source and target is incompatible with the Lorentz transformations; therefore
it is not possible to distinguish between source and target, even with
reference to a definite reference frame.


title: Crack Formation in Laponite Gel under AC Fields

abstract:
  Crack formation patterns in laponite gel are known to be strongly affected by
DC electric fields. We show that AC fields produce equally remarkable patterns
in a radially symmetric set-up. The character of the pattern depends crucially
on the field strength. A significant feature observed is the bending of radial
cracks, with the curvature increasing as field strength is increased. Fields of
20 to 70 V have been applied and several features of the resulting patterns
quantified. Striations on the fracture surfaces and crack speeds are also
studied.


title: A Clustering Analysis of the Morphology of the 130 GeV Gamma-Ray Feature

abstract:
  Recent observations indicating the existence of a monochromatic gamma-ray
line with energy ~130 GeV in the Fermi-LAT data have attracted great interest
due to the possibility that the line feature stems from the annihilation of
dark matter particles. Many studies examining the robustness of the putative
line-signal have concentrated on its spectral attributes. Here, we study the
morphological features of the gamma-ray line photons, which can be used to
differentiate a putative dark matter signal from astrophysical backgrounds or
instrumental artifacts. Photons stemming from dark matter annihilation will
produce events tracing a specific morphology, with a statistical clustering
that can be calculated based on models of the dark matter density profile in
the inner Galaxy. We apply the DBSCAN clustering algorithm to Fermi gamma-ray
data, and show that we can rule out the possibility that 1 (2, 4) or fewer
point-like sources produce the observed morphology for the line photons at a
99% (95%, 90%) confidence level. Our study strongly disfavors the main
astrophysical background envisioned to produce a line feature at energies above
100 GeV: cold pulsar winds. It is highly unlikely that 4 or more such objects
have exactly the same monochromatic cosmic-ray energy needed to produce a
gamma-ray line, to within instrumental energy resolution. Furthermore, we show
that the larger photon statistics expected with Air Cherenkov Telescopes such
as H.E.S.S.-II will allow for extraordinarily stringent morphological tests of
the origin of the "line photons".


title:
The environmental dependence of the stellar mass function at z~1:
  Comparing cluster and field between the GCLASS and UltraVISTA surveys

abstract:
  We present the stellar mass functions (SMFs) of star-forming and quiescent
galaxies from observations of 10 rich clusters in the Gemini Cluster
Astrophysics Spectroscopic Survey (GCLASS) in the redshift range 0.86<z<1.34.
We compare our results with field measurements at similar redshifts using data
from a Ks-band selected catalogue of the COSMOS/UltraVISTA field. We construct
a Ks-band selected multi-colour catalogue for the clusters in 11 photometric
bands covering u-8um, and estimate photometric redshifts and stellar masses
using SED fitting techniques. To correct for interlopers in our cluster sample,
we use the deep spectroscopic component of GCLASS, which contains spectra for
1282 identified cluster and field galaxies taken with Gemini/GMOS. Both the
photometric and spectroscopic samples are sufficiently deep that we can probe
the SMF down to masses of 10^10 Msun. We distinguish between star-forming and
quiescent galaxies using the rest-frame U-V versus V-J diagram, and find that
the best-fitting Schechter parameters alpha and M* are similar within the
uncertainties for these galaxy types within the different environments.
However, there is a significant difference in the shape and normalisation of
the total SMF between the clusters and the field sample. This difference in the
total SMF is primarily a reflection of the increased fraction of quiescent
galaxies in high-density environments. We apply a simple quenching model that
includes components of mass- and environment-driven quenching, and find that in
this picture 45% of the star-forming galaxies, which normally would be forming
stars in the field, are quenched by the cluster. If galaxies in clusters and
the field quench their star formation via different mechanisms, these processes
have to conspire in such a way that the shapes of the quiescent and
star-forming SMF remain similar in these different environments.


title:
Gluino-driven Radiative Breaking, Higgs Boson Mass, Muon $\mathbf{g-2}$,
  and the Higgs Diphoton Decay in SUGRA Unification

abstract:
  We attempt to reconcile seemingly conflicting experimental results on the
Higgs boson mass, the anomalous magnetic moment of the muon, null results in
search for supersymmetry at the LHC within the 8\TeV data and results from
$B$-physics, all within the context of supersymmetric grand unified theories.
Specifically, we consider a supergravity grand unification model with
non-universal gaugino masses where we take the $\mathrm{SU}(3)_C$ gaugino field
to be much heavier than the other gaugino and sfermion fields at the
unification scale. This construction naturally leads to a large mass splitting
between the slepton and squark masses, due to the mass splitting between the
electroweak gauginos and the gluino. The heavy Higgs bosons and Higgsinos also
follow the gluino toward large masses. We carry out a Bayesian Monte Carlo
analysis of the parametric space and find that it can simultaneously explain
the large Higgs mass, and the anomalous magnetic moment of the muon, while
producing a negligible correction to the Standard Model prediction for
$\mathcal{B}r(B^0_s\to\mu^+\mu^-)$. We also find that the model leads to an
excess in the Higgs diphoton decay rate. A brief discussion of the possibility
of detection of the light particles is given. Also discussed are the
implications of the model for dark matter.


title: An Infinite Set of Ward Identities for Adiabatic Modes in Cosmology

abstract:
  We show that the correlation functions of any single-field cosmological model
with constant growing-modes are constrained by an infinite number of novel
consistency relations, which relate (N+1)-point correlation functions with a
soft-momentum scalar or tensor mode to a symmetry transformation on N-point
correlation functions of hard-momentum modes. We derive these consistency
relations from Ward identities for an infinite tower of non-linearly realized
global symmetries governing scalar and tensor perturbations. These symmetries
can be labeled by an integer n. At each order n, the consistency relations
constrain - completely for n=0,1, and partially for n>= 2 - the q^n behavior of
the soft limits. The identities at n=0 recover Maldacena's original consistency
relations for a soft scalar and tensor mode, n=1 gives the recently-discovered
conformal consistency relations, and the identities for n>= 2 are new. As a
check, we verify directly that the n=2 identity is satisfied by known
correlation functions in slow-roll inflation.


title: Diffraction in Time: An Exactly Solvable Model

abstract:
  In the recent years, mater-wave interferometry has attracted growing
attention due to its unique suitability for high-precision measurements and
study of fundamental aspects of quantum theory. Diffraction and interference of
matter waves can be observed not only at a spatial aperture (such as a screen
edge, slit, or grating), but also at a time-domain aperture (such as an
absorbing barrier, or "shutter", that is being periodically switched on and
off). The wave phenomenon of the latter type is commonly referred to as
"diffraction in time". Here, we introduce a versatile, exactly solvable model
of diffraction in time. It describes time-evolution of an arbitrary initial
quantum state in the presence of a time-dependent absorbing barrier, governed
by an arbitrary aperture function. Our results enable a quantitative
description of diffraction and interference patterns in a large variety of
setups, and may be used to devise new diffraction and interference experiments
with atoms and molecules.


title:
Holographic Gravitational Anomaly in First and Second Order
  Hydrodynamics

abstract:
  We compute, in the framework of the fluid/gravity correspondence, the
transport coefficients of a relativistic fluid affected by chiral and
gauge-gravitational anomalies, including external electromagnetic fields. The
computation is performed at first and second order in the hydrodynamical
expansion. We use a 5-dim holographic model with pure gauge and mixed
gauge-gravitational Chern-Simons terms in the action. We reproduce at first
order previous results on the anomaly induced current of a magnetic field and a
vortex in a relativistic fluid, and compute at second order the anomalous and
non anomalous transport coefficients by using a Weyl covariant formalism. We
find a dissipative and anomalous correction to the chiral magnetic conductivity
due to the time dependence of the magnetic field. We also find a new
contribution from the mixed gauge-gravitational anomaly to the shear waves
dispersion relation. The role played by the chiral and gravitational anomalies
in other transport coefficients is discussed.


title: Inexact Coordinate Descent: Complexity and Preconditioning

abstract:
  In this paper we consider the problem of minimizing a convex function using a
randomized block coordinate descent method. One of the key steps at each
iteration of the algorithm is determining the update to a block of variables.
Existing algorithms assume that in order to compute the update, a particular
subproblem is solved exactly. In his work we relax this requirement, and allow
for the subproblem to be solved inexactly, leading to an inexact block
coordinate descent method. Our approach incorporates the best known results for
exact updates as a special case. Moreover, these theoretical guarantees are
complemented by practical considerations: the use of iterative techniques to
determine the update as well as the use of preconditioning for further
acceleration.


title: A Semantics for Approximate Program Transformations

abstract:
  An approximate program transformation is a transformation that can change the
semantics of a program within a specified empirical error bound. Such
transformations have wide applications: they can decrease computation time,
power consumption, and memory usage, and can, in some cases, allow
implementations of incomputable operations. Correctness proofs of approximate
program transformations are by definition quantitative. Unfortunately, unlike
with standard program transformations, there is as of yet no modular way to
prove correctness of an approximate transformation itself. Error bounds must be
proved for each transformed program individually, and must be re-proved each
time a program is modified or a different set of approximations are applied. In
this paper, we give a semantics that enables quantitative reasoning about a
large class of approximate program transformations in a local, composable way.
Our semantics is based on a notion of distance between programs that defines
what it means for an approximate transformation to be correct up to an error
bound. The key insight is that distances between programs cannot in general be
formulated in terms of metric spaces and real numbers. Instead, our semantics
admits natural notions of distance for each type construct; for example,
numbers are used as distances for numerical data, functions are used as
distances for functional data, an polymorphic lambda-terms are used as
distances for polymorphic data. We then show how our semantics applies to two
example approximations: replacing reals with floating-point numbers, and loop
perforation.