title: The Discovery of Quasars and its Aftermath

abstract:
  Although the extragalactic nature of quasars was discussed as early as 1960,
it was rejected largely because of preconceived ideas about what appeared to be
an unrealistically high radio and optical luminosity. Following the 1962
occultations of the strong radio source 3C 273 at Parkes, and the subsequent
identification with an apparent stellar object, Maarten Schmidt recognized that
the relatively simple hydrogen line Balmer series spectrum implied a redshift
of 0.16 Successive radio and optical measurements quickly led to the
identification of other quasars with increasingly large redshifts and the
general, although for some decades not universal, acceptance of quasars as
being by far the most distant and the most luminous objects in the Universe.
Curiously, 3C 273, which is one of the strongest extragalactic sources in the
sky, was first cataloged in 1959 and the magnitude 13 optical counterpart was
observed at least as early as 1887. Since 1960, much fainter optical
counterparts were being routinely identified using accurate radio
interferometer positions, measured primarily at the Caltech Owens Valley Radio
Observatory. However, 3C 273 eluded identification until the series of lunar
occultation observations led by Cyril Hazard, although inexplicably there was
an earlier mis-identification with a faint galaxy located about an arc minute
away from the true position. Ironically, due to calculation error, the
occultation position used by Schmidt to determine the redshift of 3C 273 was in
error by 14 arcseconds, and a good occultation position was not derived until
after Schmidt had obtained his 200 inch spectrum.


title: Dynamical probing of a topological phase of bosons in one dimension

abstract:
  We study the linear response to time-dependent probes of a symmetry-protected
topological phase of bosons in one-dimension, the Haldane insulator (HI). This
phase is separated from the ordinary Mott insulator (MI) and density-wave (DW)
phases by continuous transitions, whose field theoretical description is here
reviewed. Using this technique, we compute the absorption spectrum to two types
of periodic perturbations and relate the findings to the nature of the critical
excitations at the transition between the different phases. The HI-MI phase
transition is topological and the critical excitations possess trivial quantum
numbers: they correspond to particles and holes at zero momentum. Our findings
are corroborated by a non-local mean-field approach, which allows us to
directly relate the predicted spectrum to the known microscopic theory.


title: A Secure And High Capacity Image Steganography Technique

abstract:
  Steganography is the science of invisible communication. The purpose of
Steganography is to maintain secret communication between two parties. The
secret information can be concealed in content such as image, audio, or video.
This paper provides a novel image steganography technique to hide multiple
secret images and keys in color cover image using Integer Wavelet Transform
(IWT). There is no visual difference between the stego image and the cover
image. The extracted secret images are also similar to the original secret
images. Very good PSNR (Peak Signal to Noise Ratio) values are obtained for
both stego and extracted secret images. The results are compared with the
results of other techniques, where single image is hidden and it is found that
the proposed technique is simple and gives better PSNR values than others.


title:
Interaction of Independent Single Photons based on Integrated Nonlinear
  Optics

abstract:
  Photons are ideal carriers of quantum information, as they can be easily
created and can travel long distances without being affected by decoherence.
For this reason, they are well suited for quantum communication. However, the
interaction between single photons is negligible under most circumstances.
Realising such an interaction is not only fundamentally fascinating but holds
great potential for emerging technologies. It has recently been shown that even
weak optical nonlinearities between single photons can be used to perform
important quantum communication tasks more efficiently than methods based on
linear optics, which have fundamental limitations. Nonlinear optical effects at
single photon levels in atomic media have been studied and demonstrated but
these are neither flexible nor compatible with quantum communication as they
impose restrictions on photons' wavelengths and bandwidths. Here we use a high
efficiency nonlinear waveguide to observe the sum-frequency generation between
a single photon and a single-photon level coherent state from two independent
sources. The use of an integrated, room-temperature device and telecom
wavelengths makes this approach to photon-photon interaction well adapted to
long distance quantum communication, moving quantum nonlinear optics one step
further towards complex quantum networks and future applications such as device
independent quantum key distribution.


title:
In-situ electron-beam lithography of deterministic single-quantum-dot
  mesa-structures using low-temperature cathodoluminescence spectroscopy

abstract:
  We report on the deterministic fabrication of sub-um mesa structures
containing single quantum dots by in-situ electron-beam lithography. The
fabrication method is based on a two-step lithography process using a
low-temperature cathodoluminescence (CL) spectroscopy setup. In the first step
the position and spectral features of single InGaAs quantum dots (QDs) are
detected by CL. Then circular sub-um mesa-structures are exactly defined by
high-resolution electron-beam lithography and subsequent etching in the second
step. CL spectroscopy and micro-photoluminscence spectroscopy demonstrate the
high optical quality of the single-QD mesa-structures with emission linewidths
below 15 ueV and g(2)(0) = 0.04. Our lithography method allows for an alignment
precision better than 100 nm which paves the way for a fully-deterministic
device technology using in-situ CL lithography.


title: Generation of quantum discord between ionic qubits via noisy processes

abstract:
  Quantum systems in mixed states can be unentangled and yet still correlated
in a way that is not possible for classical systems. These correlations can be
quantified by the quantum discord and might provide a resource for certain
mixed-state quantum information processing tasks. Here we report on the
generation of discordant states of two trapped atomic ions via Markovian
decoherence processes. While entanglement is strictly non-increasing under such
operations, discord can be generated in various forms. Firstly we show that,
starting from two classically correlated qubits, it is possible to generate
discord by applying decoherence to just one of them. Secondly, even when
starting with completely uncorrelated systems, we show that discord can be
generated via classically correlated decoherence processes. Finally, the Werner
states are created. The generated states can be used as a resource state for
quantum information transmission and could be readily extended to more ions.


title:
Intrinsic rotation driven by non-Maxwellian equilibria in tokamak
  plasmas

abstract:
  The effect of small deviations from a Maxwellian equilibrium on turbulent
momentum transport in tokamak plasmas is considered. These non-Maxwellian
features, arising from diamagnetic effects, introduce a strong dependence of
the radial flux of co-current toroidal angular momentum on collisionality: As
the plasma goes from nearly collisionless to weakly collisional, the flux
reverses direction from radially inward to outward. This indicates a
collisionality-dependent transition from peaked to hollow rotation profiles,
consistent with experimental observations of intrinsic rotation.


title: Towards the Little Bang Standard Model

abstract:
  I review recent progress in developing a complete dynamical model for the
evolution of the Little Bang fireballs created in relativistic heavy-ion
collisions, and using the model to extract the transport properties and initial
density fluctuations of the liquid quark-gluon plasma state of matter of which
makes up these Little Bangs during the first half of their lives.


title:
Convergence of the least squares shadowing method for computing
  derivative of ergodic averages

abstract:
  For a parameterized hyperbolic system $u_{i+1} = f(u_i,s)$, the derivative of
an ergodic average $\ < J\ > = \underset{n\rightarrow\infty}{\lim} \frac1n
\sum_1^n J(u_i,s)$ to the parameter $s$ can be computed via the least squares
sensitivity method. This method solves a constrained least squares problem and
computes an approximation to the desired derivative $d\ < J\ > \over ds$ from
the solution. This paper proves that as the size of the least squares problem
approaches infinity, the computed approximation converges to the true
derivative.


title: Triply heavy baryon mass estimated within pNRQCD

abstract:
  Potential-NRQCD offers an effective-theory based approach to heavy-quark
physics. While meson Q-anti_Q computations are tractable in pure
alpha_s-perturbation theory, more complex many-body quark systems transcend it.
A possibility inherited from nuclear physics is to employ the perturbative
static potentials in a numerical diagonalization, eventually obtaining the
exact lowest eigenvalue in each channel for a given-order perturbative
potential. The power counting is manifest in the potential instead of the
spectrum. The NNLO-potential for the 3-body problem is already available, so we
have addressed triply-heavy baryons in this initial work with a computer-aided
2-parameter variational treatment.


title: Integrating influenza antigenic dynamics with molecular evolution

abstract:
  Influenza viruses undergo continual antigenic evolution allowing mutant
viruses to evade host immunity acquired to previous virus strains. Antigenic
phenotype is often assessed through pairwise measurement of cross-reactivity
between influenza strains using the hemagglutination inhibition (HI) assay.
Here, we extend previous approaches to antigenic cartography, and
simultaneously characterize antigenic and genetic evolution by modeling the
diffusion of antigenic phenotype over a shared virus phylogeny. Using HI data
from influenza lineages A/H3N2, A/H1N1, B/Victoria and B/Yamagata, we determine
patterns of antigenic drift across viral lineages, showing that A/H3N2 evolves
faster and in a more punctuated fashion than other influenza lineages. We also
show that year-to-year antigenic drift appears to drive incidence patterns
within each influenza lineage. This work makes possible substantial future
advances in investigating the dynamics of influenza and other
antigenically-variable pathogens by providing a model that intimately combines
molecular and antigenic evolution.


title: A phenomenological multiband Eliashberg model for LiFeAs

abstract:
  The phenomenology of LiFeAs superconductor can be explained in the framework
of a four-band s$\pm$-wave Eliashberg theory. We have examined the experimental
data available in literature and we have found out that it is possible to
reproduce the experimental critical temperature, the gap values and the upper
critical magnetic field within an effective model in moderate strong-coupling
regime that must include both an intraband term $\lambda_{11}\sim0.9$ and an
interband spin-fluctuations ($\lambda_{tot}^{sf}\sim1.5$) coupling. The
presence of a non negligible intraband coupling can be a fictitious effect of
the violation of Migdal's Theorem.


title: Identification of discontinuities in plasma plume evolution

abstract:
  The ejection of material during laser ablation gives rise to the development
of discontinuities in the ambient gas. Several of these discontinuities are
observed and characterized, including externally and internally propagating
shock waves, contact surface, and the ionization front. Qualitative
experimental observations and analysis of these discontinuities is presented.
Results from shadowgraphy enabled determination of an irradiance threshold
between two different ablation mechanisms, and determination of several stages
of plasma plume evolution. Consideration of the refractive index as a dynamic
sum of the contributions from gas and electrons led to separate identification
of ionization front from the contact surface. Furthermore, ionization front was
observed to lead the shock wave at the earlier stage of the ablation.


title: Aloha Games with Spatial Reuse

abstract:
  Aloha games study the transmission probabilities of a group of
non-cooperative users which share a channel to transmit via the slotted Aloha
protocol. This paper extends the Aloha games to spatial reuse scenarios, and
studies the system equilibrium and performance. Specifically, fixed point
theory and order theory are used to prove the existence of a least fixed point
as the unique Nash equilibrium (NE) of the game and the optimal choice of all
players. The Krasovskii's method is used to construct a Lyapunov function and
obtain the conditions to examine the stability of the NE. Simulations show that
the theories derived are applicable to large-scale distributed systems of
complicated network topologies. An empirical relationship between the network
connectivity and the achievable total throughput is finally obtained through
simulations.


title:
The electromagnetic fields and the radiation of a spatio-temporally
  varying electric current loop

abstract:
  The electric and magnetic fields of a spatio-temporally varying electric
current loop are calculated using the Jefimenko equations. The radiation and
the nonradiation parts of the electromagnetic fields are derived in the
framework of Maxwell's theory of electromagnetic fields. In this way, a new,
exact, analytical solution of the Maxwell equation is found.


title:
How to determine the branch points of correlation functions in Euclidean
  space

abstract:
  Two-point correlators represented by either perturbative or non-perturbative
integral equations in Euclidean space are considered. In general, it is
difficult to determine the analytic structure of arbitrary correlators
analytically. When relying on numerical methods to evaluate the analytic
structure, exact predictions of, e.g., branch point locations (i.e., the
multi-particle threshold) provide a useful check. These branch point locations
can be derived by Cutkosky's cut rules. However, originally they were derived
in Minkowski space for propagators with real masses and are thus not directly
applicable in Euclidean space and for propagators of a more general form.
Following similar considerations that led Karplus et al., Landau and Cutkosky
more than 50 years ago to the mass summation formula that became known as
Cutkosky's cut rules, we show how the position of branch points can be derived
analytically in Euclidean space from propagators of very general form.


title: Enhancement of spin propagation due to interlayer exciton condensation

abstract:
  We show that an interlayer exciton condensate doped into a strongly
correlated Mott insulator exhibits a remarkable enhancement of the bandwidth of
the magnetic excitations (triplons). This triplon is visible in the dynamical
magnetic susceptibility and can be measured using resonant inelastic X-ray
scattering. The bandwidth of the triplon scales with the exciton superfluid
density, but only in the limit of strong correlations. As such the triplon
bandwidth acts as a probe of exciton-spin interactions in the condensate.


title:
Controlling the Interactions between Soft Colloids via Surface
  Adsorption

abstract:
  By employing monomer-resolved computer simulations and analytical
considerations based on polymer scaling theory, we analyze the conformations
and interactions of multiarm star polymers strongly adsorbed on a smooth,
two-dimensional plane. We find a stronger stretching of the arms as well as a
stronger repulsive, effective interaction than in the three dimensional case.
In particular, the star size scales with the number of arms $f$ as $\sim
f^{1/4}$ and the effective interaction as $\sim f^{2}$, as opposed to $\sim
f^{1/5}$ and $\sim f^{3/2}$, respectively, in three dimensions. Our results
demonstrate the dramatic effect that geometric confinement can have on the
effective interactions and the subsequent correlations of soft colloids in
general, for which the conformation can be altered as a result of geometrical
constraints imposed on them.


title: Equivariant operational Chow rings of T-linear schemes

abstract:
  We study $T$-linear schemes, a class of objects that includes spherical and
Schubert varieties. We provide a localization theorem for the equivariant Chow
cohomology of these schemes that does not depend on resolution of
singularities. Furthermore, we give an explicit presentation of the equivariant
Chow cohomology of possibly singular complete spherical varieties admitting a
smooth equivariant envelope (e.g. group embeddings).


title: Network connectivity through small openings

abstract:
  Network connectivity is usually addressed for convex domains where a direct
line of sight exists between any two transmitting/receiving nodes. Here, we
develop a general theory for the network connectivity properties across a small
opening, rendering the domain essentially non-convex. Our analytic approach can
go only so far as we encounter what is referred to in statistical physics as
quenched disorder making the problem non-trivial. We confirm our theory through
computer simulations, obtain leading order approximations and discuss possible
extensions and applications.


title: Schwarzschild solution as a result of thermodynamics

abstract:
  We obtain the Schwarzschild solution from thermodynamic considerations using
the assumptions of a quasi local mass form (the Misner-Sharp mass) and
geometric surface gravity in a spherically symmetric spacetime. The deduction
is extended to other cases such as the de Sitter, anti-de Sitter,
Reissner-Nordstr\"om and higher dimensional spacetimes. This paper demonstrates
the simple hypotheses to obtain these known spherically symmetric solutions via
thermodynamics, where essentially the Misner-Sharp mass is the mass for an
adiabatic system.

categories: gr-qc astro-ph.CO hep-th math-ph math.MP


title: Super-Inflation, Non-Singular Bounce, and Low Multipoles

abstract:
  In this paper we present a simple argument that shows a non-singular bouncing
cosmology naturally yields an era of super-inflation which can precede the
phase of normal potential driven inflation. One of the consequences of a
super-inflation phase is that it might be able to account for suppressing the
low multipole in the amplitude of the cosmic microwave background radiation. We
are able to constrain the number of e-folds of super-inflation from the current
Planck data to be roughly 3 e-folds in a model independent way.


title:
Spin Gap and the Nature of the 4d3 Magnetic Ground State in the
  Frustrated FCC Antiferromagnet Ba2YRuO6

abstract:
  The geometrically frustrated double perovskite Ba2YRuO6 has magnetic 4d3 Ru5+
ions decorating an undistorted face-centered cubic (FCC) lattice. This material
has been previously reported to exhibit commensurate long-range
antiferromagnetic order below T_N = 36K, a factor f = 15 times lower than its
Curie-Weiss temperature Theta_CW = -522 K, and purported short-range order to
T* = 47K. We report new time-of-flight neutron spectroscopy of Ba2YRuO6 which
shows the development of a 5 meV spin gap in the vicinity of the [100] magnetic
ordering wavevector below T_N = 36K, with the transition to long-range order
occurring at T* = 47K. We also report spin waves extending to 14 meV, a
surprisingly small bandwidth in light of the large Theta_CW. We compare the
spin gap and bandwidth to relevant neutron studies of the isostructural 4d1
material Ba2YMoO6,and discuss the results in the framework of relatively strong
spin-orbit coupling expected in 4d magnetic systems.


title: A note on a sumset in $\mathbb{Z}_{2k}$

abstract:
  Let $A$ and $B$ be additive sets of $\mathbb{Z}_{2k}$, where $A$ has
cardinality $k$ and $B=v.\complement A$ with $v\in\mathbb{Z}_{2k}^{\times}$. In
this note some bounds for the cardinality of $A+B$ are obtained, using four
different approaches. We also prove that in a special case the bound is not
sharp and we can recover the whole group as a sumset.


title: Decoupling Can Revive Minimal Supersymmetric SU(5)

abstract:
  We revisit proton decay via the color-triplet Higgs multiplets in the minimal
supersymmetric grand unified model with heavy sfermions. Although the model has
been believed to be excluded due to the too short lifetime of proton, we have
found that it is possible to evade the experimental constraints on the proton
decay rate if the supersymmetric particles have masses much heavier than the
electroweak scale. With such heavy sfermions, the 126GeV Higgs boson is
naturally explained, while they do not spoil the gauge coupling unification and
the existence of dark matter candidates. Since the resultant proton lifetime
lies in the regions which may be reached in the future experiments, proton
decay searches may give us a chance to verify the scenario as well as the
supersymmetric grand unified models.


title: The mode-locking transition of random lasers

abstract:
  The discovery of the spontaneous mode-locking of lasers, i.e., the
synchronous oscillation of electromagnetic modes in a cavity, has been a
milestone of photonics allowing the realization of oscillators delivering
ultra-short pulses. This process is so far known to occur only in standard
ordered lasers with meter size length and only in the presence of a specific
device (the saturable absorber). Here we demonstrate that mode-locking can
spontaneously arise also in random lasers composed by micronsized laser
resonances dwelling in intrinsically disordered, self-assembled clusters of
nanometer-sized particles. Moreover by engineering a novel mode-selective
pumping mechanism we show that it is possible to continuously drive the system
from a configuration in which the various excited electromagnetic modes
oscillate in the form of several, weakly interacting, resonances to a
collective strongly interacting regime. By realizing the smallest mode-locking
device ever fabricated, we open the way to novel generation of miniaturized and
all-optically controlled light sources.


title: Algorithms for Cut Problems on Trees

abstract:
  We study the {\sc multicut on trees} and the {\sc generalized multiway Cut on
trees} problems. For the {\sc multicut on trees} problem, we present a
parameterized algorithm that runs in time $O^{*}(\rho^k)$, where $\rho =
\sqrt{\sqrt{2} + 1} \approx 1.555$ is the positive root of the polynomial
$x^4-2x^2-1$. This improves the current-best algorithm of Chen et al. that runs
in time $O^{*}(1.619^k)$. For the {\sc generalized multiway cut on trees}
problem, we show that this problem is solvable in polynomial time if the number
of terminal sets is fixed; this answers an open question posed in a recent
paper by Liu and Zhang. By reducing the {\sc generalized multiway cut on trees}
problem to the {\sc multicut on trees} problem, our results give a
parameterized algorithm that solves the {\sc generalized multiway cut on trees}
problem in time $O^{*}(\rho^k)$, where $\rho = \sqrt{\sqrt{2} + 1} \approx
1.555$ time.


title: Active subnanometer spectral control of a random laser

abstract:
  We demonstrate an experimental technique that allows to achieve a robust
control on the emission spectrum of a micro random laser and to select
individual modes with sub-nanometer resolution. The presented approach relies
on an optimization protocol of the spatial profile of the pump beam. Here we
demonstrate not only the possibility to increase the emission at a wavelength,
but also that we can isolate an individual peak suppressing unwanted
contributions form other modes.


title:
A numerical evaluation of vacuum polarization tensor in constant
  external magnetic fields

abstract:
  Hattori-Itakura have recently derived the full Landau-level summation form
for the photon vacuum polarization tensor in constant external magnetic fields
at the one-loop level. The Landau-level summation form is essential when the
photon momentum exceeds the threshold of the pair creation of charged particles
in a magnetic field stronger than the squared mass of the charged particle. The
tensor has three different form factors depending on the tensor direction with
respect to the external magnetic field. The renormalization is nontrivial
because these form factors are expressed in terms of double or triple summation
forms. We give a numerical UV subtraction method which can be applied to
numerically evaluate the form factors in constant external magnetic fields. We
numerically investigate the photon vacuum polarization tensor in the form of
the Landau-level summation and estimate the systematic errors coming from
truncation of the Landau-level summation in a parameter region realized in
heavy ion collision experiments. We find that the error is practically
controllable at an $O(10^{-2})$ level for electrons and muons in strong
magnetic fields expected in heavy ion collisions in the experimentally feasible
kinematic parameter regions.


title: Bispectrum for non-Gaussian homogenous and isotropic field on the plane

abstract:
  The object of this paper is to characterize the third order moments
(cumulants) and bispectra of a homogeneous isotropic field defined on a plane.
We establish a one to one correspondence between the third order cumulants and
the bispectra of such a process in terms of Bessel functions.


title:
Mechanical signaling via nonlinear wavefront propagation in a
  mechanically-excitable medium

abstract:
  Models that invoke nonlinear wavefront propagation in a chemically excitable
medium are rife in the biological literature. Indeed, the idea that wavefront
propagation can serve as a signaling mechanism has often been invoked to
explain synchronization of developmental processes. In this paper we suggest a
new kind of signaling based not on diffusion of a chemical species but on the
propagation of mechanical stress. We construct a theoretical approach to
describe mechanical signaling as a nonlinear wavefront propagation problem and
study its dependence on key variables such as the effective elasticity and
damping of the medium.


title:
Efficient One-Way Secret-Key Agreement and Private Channel Coding via
  Polarization

abstract:
  We introduce explicit schemes based on the polarization phenomenon for the
tasks of one-way secret key agreement from common randomness and private
channel coding. For the former task, we show how to use common randomness and
insecure one-way communication to obtain a strongly secure key such that the
key construction has a complexity essentially linear in the blocklength and the
rate at which the key is produced is optimal, i.e., equal to the one-way
secret-key rate. For the latter task, we present a private channel coding
scheme that achieves the secrecy capacity using the condition of strong secrecy
and whose encoding and decoding complexity are again essentially linear in the
blocklength.


title:
Correlator expansion approach to stationary states of weakly coupled
  cavity arrays

abstract:
  We introduce a method for calculating the stationary state of a translation
invariant array of weakly coupled cavities in the presence of dissipation and
coherent as well as incoherent drives. Instead of computing the full density
matrix our method directly calculates the correlation functions which are
relevant for obtaining all local quantities of interest. It considers an
expansion of the correlation functions and their equations of motion in powers
of the photon tunneling rate between adjacent cavities, leading to an exact
second order solution for any number of cavities. Our method provides a
controllable approximation for weak tunneling rates applicable to the strongly
correlated regime that is dominated by nonlinearities in the cavities and thus
of high interest.


title:
Monte-Carlo study of the semimetal-insulator phase transition in
  monolayer graphene with realistic inter-electron interaction potential

abstract:
  We report on the results of the first-principle numerical study of
spontaneous breaking of chiral (sublattice) symmetry in suspended monolayer
graphene due to electrostatic interaction, which takes into account the
screening of Coulomb potential by electrons on $\sigma$-orbitals. In contrast
to the results of previous numerical simulations with unscreened potential, we
find that suspended graphene is in the conducting phase with unbroken chiral
symmetry. This finding is in agreement with recent experimental results by the
Manchester group \cite{Elias et al, 2011}. Further, by artificially increasing
the interaction strength we demonstrate that suspended graphene is quite close
to the phase transition associated with spontaneous chiral symmetry breaking,
which suggests that fluctuations of chirality and nonperturbative effects might
still be quite important.


title:
Electric Field Tuning of the Surface Band Structure of Topological
  Insulator Sb2Te3 Thin Films

abstract:
  We measured the response of the surface state spectrum of epitaxial Sb2Te3
thin films to applied gate electric fields by low temperature scanning
tunneling microscopy. The gate dependent shift of the Fermi level and the
screening effect from bulk carriers vary as a function of film thickness. We
observed a gap opening at the Dirac point for films thinner than four quintuple
layers, due to the coupling of the top and bottom surfaces. Moreover, the top
surface state band gap of the three quintuple layer films was found to be
tunable by back gate, indicating the possibility of observing a topological
phase transition in this system. Our results are well explained by an effective
model of 3D topological insulator thin films with structure inversion
asymmetry, indicating that three quintuple layer Sb2Te3 films are topologically
nontrivial and belong to the quantum spin Hall insulator class.


title: Orderable Contact Structures on Liouville-fillable Contact Manifolds

abstract:
  We study the existence of positive loops of contactomorphisms on a
Liouville-fillable contact manifold $(\Sigma,\xi=\ker(\alpha))$. Previous
results show that a large class of Liouville-fillable contact manifolds admit
contractible positive loops. In contrast, we show that for any
Liouville-fillable $(\Sigma,\alpha)$ with $\dim(\Sigma) \geq 7$, there exists a
Liouville-fillable contact structure $\xi'$ on $\Sigma$ which admits no
positive loop at all. Further, $\xi'$ can be chosen to agree with $\xi$ on the
complement of a Darboux ball.


title:
Cooperative localization by dual foot-mounted inertial sensors and
  inter-agent ranging

abstract:
  The implementation challenges of cooperative localization by dual
foot-mounted inertial sensors and inter-agent ranging are discussed and work on
the subject is reviewed. System architecture and sensor fusion are identified
as key challenges. A partially decentralized system architecture based on
step-wise inertial navigation and step-wise dead reckoning is presented. This
architecture is argued to reduce the computational cost and required
communication bandwidth by around two orders of magnitude while only giving
negligible information loss in comparison with a naive centralized
implementation. This makes a joint global state estimation feasible for up to a
platoon-sized group of agents. Furthermore, robust and low-cost sensor fusion
for the considered setup, based on state space transformation and
marginalization, is presented. The transformation and marginalization are used
to give the necessary flexibility for presented sampling based updates for the
inter-agent ranging and ranging free fusion of the two feet of an individual
agent. Finally, characteristics of the suggested implementation are
demonstrated with simulations and a real-time system implementation.


title:
The ultra-deep XMM survey in the CDFS: X-ray spectroscopy of heavily
  obscured AGN

abstract:
  We present selected results on the X-ray spectroscopy of distant, obscured
AGN as obtained with the ultra-deep (~3 Ms) XMM-Newton survey in the Chandra
Deep Field South (CDF-S). One of the primary goals of the project is to
characterize the X-ray spectral properties of heavily obscured and
Compton-thick AGN over the range of redshifts and luminosities that are
relevant in terms of their contribution to the X-ray background. The ultra-deep
exposure, coupled with the XMM detector's spectral throughput, allowed us to
accumulate X-ray spectra for more than 100 AGN to investigate the absorption
distribution up to z~4.


title:
The cosmic X-ray background: abundance and evolution of hidden black
  holes

abstract:
  The growth of supermassive black holes across cosmic time leaves a radiative
imprint recorded in the X-ray background (XRB). The XRB spectral shape suggests
that a large population of distant, hidden nuclei must exist, which are now
being revealed at higher and higher redshifts by the deepest surveys performed
by Chandra and XMM.
  Our current understanding of the XRB emission in terms of AGN population
synthesis models is here reviewed, and the evolutionary path of nuclear
accretion and obscuration, as emerging from the major X-ray surveys, is
investigated. The role of galaxy merging versus secular processes in triggering
nuclear activity is also discussed in the framework of recent galaxy/black hole
co-evolutionary scenarios. Finally, the limits of current instrumentation in
the detection of the most obscured and distant black holes are discussed and
some possible directions to overcome these limits are presented.


title: Sets Represented as the Length-n Factors of a Word

abstract:
  In this paper we consider the following problems: how many different subsets
of Sigma^n can occur as set of all length-n factors of a finite word? If a
subset is representable, how long a word do we need to represent it? How many
such subsets are represented by words of length t? For the first problem, we
give upper and lower bounds of the form alpha^(2^n) in the binary case. For the
second problem, we give a weak upper bound and some experimental data. For the
third problem, we give a closed-form formula in the case where n <= t < 2n.
Algorithmic variants of these problems have previously been studied under the
name "shortest common superstring".


title: Chaos on the conveyor belt

abstract:
  The dynamics of a spring-block train placed on a moving conveyor belt is
investigated both by simple experiments and computer simulations. The first
block is connected by spring to an external static point, and due to the
dragging effect of the belt the blocks undergo complex stick-slip dynamics. A
qualitative agreement with the experimental results can only be achieved by
taking into account the spatial inhomogeneity of the friction force on the
belt's surface, modeled as noise. As a function of the velocity of the conveyor
belt and the noise strength, the system exhibits complex, self-organized
critical, sometimes chaotic dynamics and phase transition-like behavior. Noise
induced chaos and intermittency is also observed. Simulations suggest that the
maximum complexity of the dynamical states is achieved for a relatively small
number of blocks, around five.

categories: nlin.CD physics.class-ph physics.comp-ph physics.pop-ph


title:
A Huygens principle for diffusion and anomalous diffusion in spatially
  extended systems

abstract:
  We present a universal view on diffusive behaviour in chaotic spatially
extended systems for anisotropic and isotropic media. For anisotropic systems,
strong chaos leads to diffusive behaviour (Brownian motion with drift) and weak
chaos leads to superdiffusive behaviour (L\'evy processes with drift). For
isotropic systems, the drift term vanishes and strong chaos again leads to
Brownian motion. We establish the existence of a nonlinear Huygens principle
for weakly chaotic systems in isotropic media whereby the dynamics behaves
diffusively in even space dimension and exhibits superdiffusive behaviour in
odd space dimensions.


title: Transition from Majorana to Weyl fermions and anapole moments

abstract:
  The apparent splitting of zero-bias conductance peaks, apparently observed in
recent experiments concerning Majorana fermions in nanowires coupled to
superconductors, can be interpreted as a manifestation of a transition in the
structure from (massive) Majorana to (massless) Weyl fermions. A modification
of the experiments in order to test such phenomenon is proposed by making
recourse to the only possible electromagnetic interaction allowed to (massive)
Majorana particles and mediated by their anapole moment. In suitably designed
heterostructures with toroidal symmetry, the additional anapole interaction
manifests itself in the lowering of the critical magnetic field required for
the appearance of the zero-bias peak, a shift that can be directly measured and
thus reveal the presence of Majorana (rather than Weyl) fermions. Anapole
interactions, though not previously considered, may also be a powerful method
to control the dynamics of Majorana fermions, and then to manipulate the qubit
state in quantum computation

categories: cond-mat.mes-hall cond-mat.supr-con hep-ph quant-ph


title: Exploring the Higgs sector of a most natural NMSSM

abstract:
  The Next to Minimal Supersymmetric Standard Model (NMSSM) with a
Higgs-singlet coupling {\lambda} close to unity, moderate tan {\beta} and stop
masses below 1 TeV minimizes the fine tuning of the electroweak scale, making
possible that the lightest new particles, except perhaps for the LSP, be part
of the extended Higgs system. We show how the measurements of the couplings of
the 126 GeV Higgs boson constrain the region of the physical parameters of a
generic NMSSM most relevant to this context. In the same region of parameter
space we determine the cross section for the production of a heavier CP-even
scalar together with its total width and its most relevant branching ratios.
For comparison we show the same analysis for the MSSM. We also comment on how a
coupling {\lambda} ~ 1 can be compatible with gauge coupling unification.


title: On topological changes in the Delaunay triangulation of moving points

abstract:
  Let $P$ be a collection of $n$ points moving along pseudo-algebraic
trajectories in the plane. One of the hardest open problems in combinatorial
and computational geometry is to obtain a nearly quadratic upper bound, or at
least a subcubic bound, on the maximum number of discrete changes that the
Delaunay triangulation $\DT(P)$ of $P$ experiences during the motion of the
points of $P$.
  In this paper we obtain an upper bound of $O(n^{2+\eps})$, for any $\eps>0$,
under the assumptions that (i) any four points can be co-circular at most
twice, and (ii) either no triple of points can be collinear more than twice, or
no ordered triple of points can be collinear more than once.


title: Efficient phase-tunable Josephson thermal rectifier

abstract:
  Josephson tunnel junctions are proposed as efficient phase-tunable thermal
rectifiers. The latter exploit the strong temperature dependence of the
superconducting density of states and phase-dependence of heat currents flowing
through Josephson junctions to operate. Remarkably, large heat rectification
coefficients up to 800% can potentially be achieved using conventional
materials and standard fabrication methods. In addition, these devices allow
for the in-situ fine tuning of the thermal rectification magnitude and
direction.


title: Bayesian analysis of matrix data with rstiefel

abstract:
  We illustrate the use of the R-package "rstiefel" for matrix-variate data
analysis in the context of two examples. The first example considers estimation
of a reduced-rank mean matrix in the presence of normally distributed noise.
The second example considers the modeling of a social network of friendships
among teenagers. Bayesian estimation for these models requires the ability to
simulate from the matrix-variate von Mises-Fisher distributions and the
matrix-variate Bingham distributions on the Stiefel manifold.


title: The Recomputation Manifesto

abstract:
  Replication of scientific experiments is critical to the advance of science.
Unfortunately, the discipline of Computer Science has never treated replication
seriously, even though computers are very good at doing the same thing over and
over again. Not only are experiments rarely replicated, they are rarely even
replicable in a meaningful way. Scientists are being encouraged to make their
source code available, but this is only a small step. Even in the happy event
that source code can be built and run successfully, running code is a long way
away from being able to replicate the experiment that code was used for. I
propose that the discipline of Computer Science must embrace replication of
experiments as standard practice. I propose that the only credible technique to
make experiments truly replicable is to provide copies of virtual machines in
which the experiments are validated to run. I propose that tools and
repositories should be made available to make this happen. I propose to be one
of those who makes it happen.


title:
Self-assembly of colloidal polymers via depletion-mediated lock and key
  binding

abstract:
  We study the depletion-induced self-assembly of indented colloids. Using
state-of-the-art Monte Carlo simulation techniques that treat the depletant
particles explicitly, we demonstrate that colloids assemble by a lock-and-key
mechanism, leading to colloidal polymerization. The morphology of the chains
that are formed depends sensitively on the size of the colloidal indentation,
with smaller values additionally permitting chain branching. In contrast to the
case of spheres with attractive patches, Wertheim's thermodynamic perturbation
theory fails to provide a fully quantitative description of the polymerization
transition. We trace this failure to a neglect of packing effects and we
introduce a modified theory that accounts better for the shape of the colloids,
yielding improved agreement with simulation.


title:
Comment on "Bayesian Nonparametric Inference - Why and How" by Mueller
  and Mitra

abstract:
  Due to their great flexibility, nonparametric Bayes methods have proven to be
a valuable tool for discovering complicated patterns in data. The term
"nonparametric Bayes" suggests that these methods inherit model-free operating
characteristics of classical nonparametric methods, as well as coherent
uncertainty assessments provided by Bayesian procedures. However, as the
authors say in the conclusion to their article, nonparametric Bayesian methods
may be more aptly described as "massively parametric." Furthermore, I argue
that many of the default nonparametric Bayes procedures are only Bayesian in
the weakest sense of the term, and cannot be assumed to provide honest
assessments of uncertainty merely because they carry the Bayesian label.
However useful such procedures may be, we should be cautious about advertising
default nonparametric Bayes procedures as either being "assumption free" or
providing descriptions of our uncertainty. If we want our nonparametric Bayes
procedures to have a Bayesian interpretation, we should modify default NP Bayes
methods to accommodate real prior information, or at the very least, carefully
evaluate the effects of hyperparameters on posterior quantities of interest.


title: An Efficient Polynomial Interior-Point Algorithm for Linear Programming

abstract:
  For interior-point algorithms in linear programming, it is well-known that
the selection of the centering parameter is crucial for proving polynomility in
theory and for efficiency in practice. However, the selection of the centering
parameter is usually by heuristics and separate from the selection of the
line-search step size. The heuristics are quite different while developing
practically efficient algorithms, such as MPC, and theoretically efficient
algorithms, such as short-step path-following algorithm. This introduces a
dilemma that some algorithms with the best-known polynomial bound are least
efficient in practice, and some most efficient algorithms may not be
polynomial. In this paper, we propose a systematic way to optimally select the
centering parameter and line-search step size at the same time, and we show
that the algorithm based on this strategy has the best-known polynomial bound
and may be very efficient in computation for real problems.


title:
Measurement of spin observables in the quasi-free np-> {pp}_s pi-
  reaction at 353 MeV

abstract:
  The transverse spin correlations A_{x,x} and A_{y,y} have been measured in
the pol{d} pol{p} -> p_spec {pp}_s pi- reaction at COSY-ANKE at 353 MeV per
nucleon. Here {pp}_s denotes a proton-proton pair with low excitation energy,
which is dominantly in the 1S0 state. By measuring three protons in the final
state it was possible to extract events where there was a spectator proton
p_spec so that the reaction could be interpreted in terms of quasi-free pol{n}
pol{p} -> {pp}_s pi-. The proton analyzing power in this reaction was also
deduced from this data set by averaging over the polarization of the deuteron
beam. The values of A_y^p were shown to be consistent with a refined analysis
of our earlier results obtained with a polarized proton incident on a deuterium
target. Taking these data in combination with our earlier measurements of the
differential cross sections and analyzing powers in the pol{p} p -> {pp}_s pi^0
reaction, a more robust partial wave decomposition was achieved. Three
different acceptable solutions were found and the only way of resolving this
ambiguity without further theoretical input would be through a measurement of
the mixed spin-correlation parameter A_{x,z}.


title:
Asymmetric dark matter annihilation as a test of non-standard
  cosmologies

abstract:
  We show that the relic abundance of the minority component of asymmetric dark
matter can be very sensitive to the expansion rate of the Universe and the
temperature of transition between a non-standard pre-Big Bang Nucleosynthesis
cosmological phase and the standard radiation dominated phase, if chemical
decoupling happens before this transition. In particular, because the
annihilation cross section of asymmetric dark matter is typically larger than
that of symmetric dark matter in the standard cosmology, the decrease in relic
density of the minority component in non-standard cosmologies with respect to
the majority component may be compensated by the increase in annihilation cross
section, so that the annihilation rate at present of asymmetric dark matter,
contrary to general belief, could be larger than that of symmetric dark matter
in the standard cosmology.


title:
Geometry-driven collapses for converting a Cech complex into a
  triangulation of a nicely triangulable shape

abstract:
  Given a set of points that sample a shape, the Rips complex of the data
points is often used in machine-learning to provide an approximation of the
shape easily-computed. It has been proved recently that the Rips complex
captures the homotopy type of the shape assuming the vertices of the complex
meet some mild sampling conditions. Unfortunately, the Rips complex is
generally high-dimensional. To remedy this problem, it is tempting to simplify
it through a sequence of collapses. Ideally, we would like to end up with a
triangulation of the shape. Experiments suggest that, as we simplify the
complex by iteratively collapsing faces, it should indeed be possible to avoid
entering a dead end such as the famous Bing's house with two rooms. This paper
provides a theoretical justification for this empirical observation.
  We demonstrate that the Rips complex of a point-cloud (for a well-chosen
scale parameter) can always be turned into a simplicial complex homeomorphic to
the shape by a sequence of collapses, assuming the shape is nicely triangulable
and well-sampled (two concepts we will explain in the paper). To establish our
result, we rely on a recent work which gives conditions under which the Rips
complex can be converted into a Cech complex by a sequence of collapses. We
proceed in two phases. Starting from the Cech complex, we first produce a
sequence of collapses that arrives to the Cech complex, restricted by the
shape. We then apply a sequence of collapses that transforms the result into
the nerve of some robust covering of the shape.


title:
A path-based approach to random walks on networks characterizes how
  proteins evolve new function

abstract:
  We develop a path-based approach to continuous-time random walks on networks
with arbitrarily weighted edges. We describe an efficient numerical algorithm
for calculating statistical properties of the stochastic path ensemble. After
demonstrating our approach on two reaction rate problems, we present a
biophysical model that describes how proteins evolve new functions while
maintaining thermodynamic stability. We use our methodology to characterize
dynamics of evolutionary adaptation, reproducing several key features observed
in directed evolution experiments. We find that proteins generally fall into
two qualitatively different regimes of adaptation depending on their binding
and folding energetics.


title:
A properness result for degenerate Quadratic and Symplectic Bundles on a
  smooth projective curve

abstract:
  Let $(V,q)$ be a vector bundle on a smooth projective curve $X$ together with
a quadratic form $q: \mathrm{Sym}^2(V) \ra \mathcal{O}_X$ (respectively
symplectic form $q: \Lambda^2V \ra \mathcal{O}_X$). Fixing the degeneracy locus
of the quadratic form induced on $V/\ker(q)$, we construct a coarse moduli of
such objects. Further, we prove semi-stable reduction theorem for equivalence
classes of such objects. In particular, the case when degeneracies of $q$ are
higher than one is that of principal interest. We also provide a proof of
properness of polystable orthogonal bundles without appealing to Bruhat-Tits
theory in any characteristic.


title:
New method for determining the light travel time in static, spherically
  symmetric spacetimes. Calculation of the terms of order $G^3$

abstract:
  A new iterative method for calculating the travel time of a photon as a
function of the spatial positions of the emitter and the receiver in the field
of a static, spherically symmetric body is presented. The components of the
metric are assumed to be expressible in power series in $m/r$, with $m$ being
half the Schwarzschild radius of the central body and $r$ a radial coordinate.
The procedure exclusively works for a light ray which may be described as a
perturbation in powers of $G$ of a Minkowskian null geodesic, with $G$ being
the Newtonian gravitational constant. It is shown that the expansion of the
travel time of a photon along such a ray only involves elementary integrals
whatever the order of approximation. An expansion of the impact parameter in
power series of $G$ is also obtained. The method is applied to explicitly
calculate the perturbation expansions of the light travel time and the impact
parameter up to the third order. The full expressions yielding the terms of
order $G^3$ are new. The expression of the travel time confirms the existence
of a third-order enhanced term when the emitter and the receiver are in
conjunction relative to the central body. This term is shown to be necessary
for determining the post-Newtonian parameter $\gamma$ at a level of accuracy of
$10^{-8}$ with light rays grazing the Sun.


title: On cotangent manifolds, complex structures and generalized geometry

abstract:
  We develop various properties of symmetric generalized complex structures (in
connection with their holomorphic space and B-field transformations), which are
analogous to the well-known results of Gualtieri on skew-symmetric generalized
complex structures. Given a symmetric or skew-symmetric generalized complex
structure \mathcal J and a connection D on a manifold M, we construct an almost
complex structure J^{\mathcal J,D} on the cotangent manifold T^{*}M and we
study its integrability. For \mathcal J skew-symmetric, we relate the Courant
integrability of \mathcal J with the integrability of J^{\mathcal J, D}. We
consider in detail the case when M=G is a Lie group and \mathcal J , D are
left-invariant. We also show that our approach generalizes various well-known
results from special complex geometry.


title: Metaspin and dirishonic dark matter

abstract:
  The antisymmetry requirement of rishon bound state wave functions suggests a
new rishon quantum number called M spin. From M spin conservation and the
Nussinov-Weingarten-Witten theorem we predict the existence of a stable
pseudoscalar dirishonic meson, called zeta, that is lighter than the lightest
neutrino. Its mass is estimated as m(zeta) = 10^{-9} eV. This particle could
make up the major part of cold dark matter in the Universe.


title:
First-principle interaction potentials for metastable He($^3$S) and
  Ne($^3$P) with closed-shell molecules. Application to Penning-Ionizing
  systems

abstract:
  We present new interaction potential curves, calculated from first-principle,
for the He$(^3$S)$...$H$_2$ and He$(^3$S)$...$Ar systems, relevant in Penning's
ionization experiments. Two different approaches were applied: supermolecular
using coupled cluster theory (CC) and perturbational within symmetry-adapted
perturbation theory (SAPT). Both methods gave consistent results and the
potentials were used to determine the positions of shape resonances in low
collision energy scattering regime. We found a good agreement with the most
recent scattering experiment of Henson {\em et al.} [Science {\bf 338}, 234
(2012)].
  In addition, we investigated two other dimers, composed of metastable Ne and
ground state He and Ar atoms. For the Ne$(^3$P)$...$He system a good agreement
between CC and SAPT approaches was obtained. The Ne$(^3$P)$...$Ar dimer was
described only with SAPT, as CC gave divergent results. Ne$^*$ systems exhibit
extremely small electronic orbital angular momentum anisotropy of the
potentials. We attribute this effect to the screening of the open 2$p$ shell by
the singly occupied 3$s$ shell.


title: Gersten-Witt Complex of Hirzebruch Surfaces

abstract: Gersten-Witt cohomologies of Hirzebruch surfaces are computed.


title: A version of H\"ormander's theorem in 2-smooth Banach spaces

abstract:
  We consider a stochastic evolution equation in a 2-smooth Banach space with a
densely and continuously embedded Hilbert subspace. We prove that under
H\"ormander's bracket condition, the image measure of the solution law under
any finite-rank bounded linear operator is absolutely continuous with respect
to the Lebesgue measure. To obtain this result, we apply methods of the
Malliavin calculus.


title: Enhancement of H -> gamma gamma in SU(5) model with 45_H plet

abstract:
  We show that the low energy effective model derived from SU(5) with 45-plet
Higgs can account for the recently reported enhanced diphoton decay rate of the
Standard Model (SM)-like Higgs with mass about 125 GeV. This model extends the
SM by an extra Higgs doublet and color-octet scalar doublet. We show that the
charged octet scalars are not severely constrained by flavor changing neutral
current and can be light. However, the K^0-\bar{K}^0 mixing implies that the
neutral octet-scalar mass should be larger than 400 GeV for \tan\beta ~ O(1).
The role of charged octet scalar in the loop of Higgs decay into diphoton is
investigated . We point out that the most significant impact of this model on
the diphoton decay width comes from the suppression of top-quark coupling with
SM-like Higgs or even flipping its sign that leads to important enhancement in
\Gamma(h -> gamma gamma). We also study the implications of the neutral
octet-scalar contributions to the gluon fusion Higgs production cross section
in alleviating the apparent tension between enhancement of diphoton decay rate
and suppression of \sigma(gg -> h).


title:
Unveiling and exemplifying the unitary equivalence of discrete time
  quantum walk models

abstract:
  The two major discrete time formulations for quantum walks, coined and
scattering, are unitarily equivalent for arbitrary position dependent
transition amplitudes and any topology (PRA {\bf 80}, 052301 (2009)). Although
the proof explicit describes the mapping obtention, its high technicality may
hinder relevant physical aspects involved in the equivalence. Discussing
concrete examples -- the most general constructions for the line, square and
honeycomb lattices -- here we unveil the similarities and differences of these
two versions of quantum walks. We moreover show how to derive the dynamics of
one from the other by means of proper projections. We perform calculations for
different probability amplitudes like, Hadamard, Grover, Discrete Fourier
Transform and the uncommon in the area (but interesting) Discrete Hartley
Transform, comparing the evolutions. Our study illustrates the models
interplay, an important issue for implementations and applications of such
systems.


title: Identifiability of a Coalescent-based Population Tree Model

abstract:
  Identifiability of evolutionary tree models has been a recent topic of
discussion and some models have been shown to be non-identifiable. A
coalescent-based rooted population tree model, originally proposed by Nielsen
et al. 1998 [2], has been used by many authors in the last few years and is a
simple tool to accurately model the changes in allele frequencies in the tree.
However, the identifiability of this model has never been proven. Here we prove
this model to be identifiable by showing that the model parameters can be
expressed as functions of the probability distributions of subsamples. This a
step toward proving the consistency of the maximum likelihood estimator of the
population tree based on this model.


title:
Investigation of wall bounded flows using SPH and the unified
  semi-analytical wall boundary conditions

abstract:
  The semi-analytical wall boundary conditions present a mathematically
rigorous framework to prescribe the influence of solid walls in SPH for fluid
flows. In this paper they are investigated with respect to the skew-adjoint
property which implies exact energy conservation. It will be shown that this
property holds only in the limit of the continuous SPH approximation, whereas
in the discrete SPH formulation it is only approximately true, leading to
numerical noise. This noise, interpreted as form of "turbulence", is treated
using an additional volume diffusion term in the continuity equation which we
show is equivalent to an approximate Riemann solver. Subsequently two
extensions to the boundary conditions are presented. The first dealing with a
variable driving force when imposing a volume flux in a periodic flow and the
second showing a generalization of the wall boundary condition to Robin type
and arbitrary-order interpolation. Two modifications for free-surface flows are
presented for the volume diffusion term as well as the wall boundary condition.
In order to validate the theoretical constructs numerical experiments are
performed showing that the present volume flux term yields results with an
error 5 orders of magnitude smaller then previous methods while the Robin
boundary conditions are imposed correctly with an error depending on the order
of the approximation. Furthermore, the proposed modifications for free-surface
flows improve the behaviour at the intersection of free surface and wall as
well as prevent free-surface detachment when using the volume diffusion term.
Finally, this paper is concluded by a simulation of a dam break over a wedge
demonstrating the improvements proposed in this paper.


title:
Bifurcation, mode coupling and noise in a nonlinear multimode
  superconducting RF resonator

abstract:
  The addition of nonlinearity to an harmonic resonator provides a route to
complex dynamical behaviour of resonant modes, including coupling between them.
We present a superconducting device that makes use of the nonlinearity of
Josephson junctions to introduce a controlled, tunable, nonlinear inductance to
a thin film coplanar waveguide resonator. Considering the device as a potential
quantum optical component in the microwave regime, we create a sensitive
bifurcation amplifier and then demonstrate spectroscopy of other resonant modes
via the intermode coupling. We find that the sensitivity of the device
approaches within a factor two quantitative agreement with a quantum model by
Dykman, but is limited by a noise that has its source(s) on-chip.


title: Origin of emergent algebras

abstract:
  This is an expository article concerning the last section "Why is the tangent
space a group?" (section 8) of the article by A. Bellaiche, The tangent space
in sub-riemannian geometry, from the viewpoint of emergent algebras.


title:
Coherent and incoherent processes responsible for various
  characteristics of nonlinear magneto-optical signals in rubidium atoms

abstract:
  We present the results of an investigation of the different physical
processes that influence the shape of the nonlinear magneto-optical signals
both at small magnetic field values (~ 100 mG) and at large magnetic field
values (several tens of Gauss). We used a theoretical model that provided an
accurate description of experimental signals for a wide range of experimental
parameters. By turning various effects "on" or "off" inside this model, we
investigated the origin of different features of the measured signals. We
confirmed that the narrowest structures, with widths on the order of 100 mG,
are related mostly to coherences among ground-state magnetic sublevels. The
shape of the curves at other scales could be explained by taking into account
the different velocity groups of atoms that come into and out of resonance with
the exciting laser field. Coherent effects in the excited state can also play a
role, although they mostly affect the polarization components of the
fluorescence. The results of theoretical calculations are compared with
experimental measurements of laser induced fluorescence from the D2 line of
atomic rubidium as a function of magnetic field.


title:
Registration of reactor neutrinos with the highly segmented plastic
  scintillator detector DANSSino

abstract:
  DANSSino is a simplified pilot version of a solid-state detector of reactor
antineutrino (it is being created within the DANSS project and will be
installed close to an industrial nuclear power reactor). Numerous tests
performed under a 3 GW(th) reactor of the Kalinin NPP at a distance of 11 m
from the core demonstrate operability of the chosen design and reveal the main
sources of the background. In spite of its small size (20x20x100 ccm), the
pilot detector turned out to be quite sensitive to reactor neutrinos, detecting
about 70 IBD events per day with the signal-to-background ratio about unity.


title:
Comment on `Vacuum Rabi Splitting in a Semiconductor Circuit QED System'
  by Toida et al., Phys. Rev. Lett. 110, 066802 - Published 6 February 2013

abstract:
  Toida et al. claim in their recent article [Phys. Rev. Lett. 110, 066802
(2013)] that they `report a direct observation of vacuum Rabi splitting in a
GaAs/AlGaAs double quantum dot (DQD) based charge qubit coupled with a
superconducting coplanar waveguide (CPW) resonator'. In this comment, we
challenge the main claims made in their paper and show that their results: a)
do not provide any evidence of vacuum Rabi oscillations and b) do not provide
any direct evidence of vacuum Rabi splitting.


title:
Integral field spectroscopy of M1-67. A Wolf-Rayet nebula with LBVN
  appearance

abstract:
  This work aims to disentangle the morphological, kinematic, and chemical
components of the nebula M1-67 to shed light on its process of formation around
the central Wolf-Rayet (WR) star WR124. We have carried out integral field
spectroscopy observations over two regions of M1-67, covering most of the
nebula in the optical range. Maps of electron density, line ratios, and radial
velocity were created to perform a detailed analysis of the two-dimensional
structure. We studied the physical and chemical properties by means of
integrated spectra selected over the whole nebula. Photoionization models were
performed to confirm the empirical chemical results theoretically. In addition,
we analysed infrared spectroscopic data and the MIPS 24micron image of M1-67
from Spitzer. We find that the ionized gas of M1-67 is condensed in knots
aligned in a preferred axis along the NE-SW direction, like a bipolar
structure. Both electron density and radial velocity decrease in this direction
when moving away from the central star. From the derived electron temperature,
Te~8200 K, we have estimated chemical abundances, obtaining that nitrogen
appears strongly enriched and oxygen depleted. From the last two results, we
infer that this bipolarity is the consequence of an ejection of an evolved
stage of WR124 with material processed in the CNO cycle. The infrared study has
revealed that the bipolar axis is composed of ionized gas with a low ionization
degree that is well mixed with warm dust and of a spherical bubble surrounding
the ejection at 24micron. Taking the evolution of a 60 Mo star and the temporal
scale of the bipolar ejection into account, we propose that the observed gas
was ejected during an eruption in the luminous blue variable. The star has
entered the WR phase recently without apparent signs of interaction between
WR-winds and interstellar material.


title: Specialisations and Algebraically Closed Fields

abstract:
  We study the theory specialisations in algebraic geometry from a model
theoretic viewpoint. In particular we investigate universality and maximality
of specialisations in algebraic geometry.


title: A planetary nervous system for social mining and collective awareness

abstract:
  We present a research roadmap of a Planetary Nervous System (PNS), capable of
sensing and mining the digital breadcrumbs of human activities and unveiling
the knowledge hidden in the big data for addressing the big questions about
social complexity. We envision the PNS as a globally distributed,
self-organizing, techno-social system for answering analytical questions about
the status of world-wide society, based on three pillars: social sensing,
social mining, and the idea of trust networks and privacy-aware social mining.
We discuss the ingredients of a science and a technology necessary to build the
PNS upon the three mentioned pillars, beyond the limitations of their
respective state-of-art. Social sensing is aimed at developing better methods
for harvesting the big data from the techno-social ecosystem and make them
available for mining, learning and analysis at a properly high abstraction
level.Social mining is the problem of discovering patterns and models of human
behaviour from the sensed data across the various social dimensions by data
mining, machine learning and social network analysis. Trusted networks and
privacy-aware social mining is aimed at creating a new deal around the
questions of privacy and data ownership empowering individual persons with full
awareness and control on own personal data, so that users may allow access and
use of their data for their own good and the common good. The PNS will provide
a goal-oriented knowledge discovery framework, made of technology and people,
able to configure itself to the aim of answering questions about the pulse of
global society. Given an analytical request, the PNS activates a process
composed by a variety of interconnected tasks exploiting the social sensing and
mining methods within the transparent ecosystem provided by the trusted
network.


title: Line Defects in Molybdenum Disulfide Layers

abstract:
  Layered molecular materials and especially MoS2 are already accepted as
promising candidates for nanoelectronics. In contrast to the bulk material, the
observed electron mobility in single-layer MoS2 is unexpectedly low. Here we
reveal the occurrence of intrinsic defects in MoS2 layers, known as inversion
domains, where the layer changes its direction through a line defect. The line
defects are observed experimentally by atomic resolution TEM. The structures
were modeled and the stability and electronic properties of the defects were
calculated using quantum-mechanical calculations based on the
Density-Functional Tight-Binding method. The results of these calculations
indicate the occurrence of new states within the band gap of the semiconducting
MoS2. The most stable non-stoichiometric defect structures are observed
experimentally, one of which contains metallic Mo-Mo bonds and another one
bridging S atoms.


title: Multiple Isotope Magneto Optical Trap from a single diode laser

abstract:
  We present a Dual Isotope Magneto Optical Trap produced using a single diode
laser. We generate all the optical frequencies needed for trapping both species
using a fiber intensity modulator. All the optical frequencies are amplified
simultaneously using a tapered amplifier. The independent control of each
frequency is on the RF side rather than on the optical side. This introduces an
enormous simplification for laser cooling applications that often require an
acousto-optic modulator for each laser beam. Frequency changing capabilities
are limited by the modulator bandwidth (10 GHz). Traps for more isotopes can be
simply added by including additional RF frequencies to the modulator.


title:
Calculation of quantum discord and entanglement measures using the
  random mutations optimization algorithm

abstract:
  The simple and universal global optimization method based on simplified
multipopulation genetic algorithm is presented. The method is applied to
quantum information problems. It is compared to the genetic algorithm on
standard test functions, and also tested on the calculation of quantum discord
and minimal entanglement entropy, which is an entanglement measure for pure
multipartite states.


title: Pearls Are Self-Organized Natural Ratchets

abstract:
  Pearls, the most flawless and highly prized of them, are perhaps the most
perfectly spherical macroscopic bodies in the biological world. How are they so
round? Why are other pearls solids of revolution (off-round, drop, ringed), and
yet others have no symmetry (baroque)? We find that with a spherical pearl the
growth fronts of nacre are spirals and target patterns distributed across its
surface, and this is true for a baroque pearl, too, but that in pearls with
rotational symmetry spirals and target patterns are found only in the vicinity
of the poles; elsewhere the growth fronts are arrayed in ratchet fashion around
the equator. We demonstrate that pearl rotation is a self-organized phenomenon
caused and sustained by physical forces from the growth fronts, and that
rotating pearls are a - perhaps unique - example of a natural ratchet.


title:
Using ISS Telescopes for Electromagnetic Follow-up of Gravitational Wave
  Detections of NS-NS and NS-BH Mergers

abstract:
  The International Space Station offers a unique platform for rapid and
inexpensive deployment of space telescopes. A scientific opportunity of great
potential later this decade is the use of telescopes for the electromagnetic
follow-up of ground-based gravitational wave detections of neutron star and
black hole mergers. We describe this possibility for OpTIIX, an ISS technology
demonstration of a 1.5 m diffraction limited optical telescope assembled in
space, and ISS-Lobster, a wide-field imaging X-ray telescope now under study as
a potential NASA mission. Both telescopes will be mounted on pointing
platforms, allowing rapid positioning to the source of a gravitational wave
event. Electromagnetic follow-up rates of several per year appear likely,
offering a wealth of complementary science on the mergers of black holes and
neutron stars.


title: Silicon detector results from the first five-tower run of CDMS II

abstract:
  We report results of a search for Weakly Interacting Massive Particles
(WIMPs) with the Si detectors of the CDMS II experiment. This report describes
a blind analysis of the first data taken with CDMS II's full complement of
detectors in 2006-2007; results from this exposure using the Ge detectors have
already been presented. We observed no candidate WIMP-scattering events in an
exposure of 55.9 kg-days before analysis cuts, with an expected background of
~1.1 events. The exposure of this analysis is equivalent to 10.3 kg-days over a
recoil energy range of 7-100 keV for an ideal Si detector and a WIMP mass of 10
GeV/c2. These data set an upper limit of 1.7x10-41 cm2 on the WIMP-nucleon
spin-independent cross section of a 10 GeV/c2 WIMP. These data exclude
parameter space for spin-independent WIMP-nucleon elastic scattering that is
relevant to recent searches for low-mass WIMPs.


title: Multistate nested canalizing functions

abstract:
  The concept of a nested canalizing Boolean function has been studied over the
course of the last decade in the context of understanding the regulatory logic
of molecular interaction networks, such as gene regulatory networks. Such
functions appear preferentially in published models of such networks. Recently,
this concept has been generalized to include multi-state functions, and a
recursive formula has been derived for their number, as a function of the
number of variables. This paper carries out a detailed analysis of the class of
nested canalizing functions over an arbitrary finite field. Furthermore, the
paper generalizes the concept further, and derives a closed formula for the
number of such generalized functions. The paper also derives a closed formula
for the number of equivalence classes under permutation of variables. This is
motivated by the fact that two nested canalizing functions that differ by a
permutation of the variables share many important properties with each other.
The paper contributes to the effort of identifying a class of functions over
finite fields that are of interest in biology and also have interesting
mathematical properties.


title: Advice-Efficient Prediction with Expert Advice

abstract:
  Advice-efficient prediction with expert advice (in analogy to label-efficient
prediction) is a variant of prediction with expert advice game, where on each
round of the game we are allowed to ask for advice of a limited number $M$ out
of $N$ experts. This setting is especially interesting when asking for advice
of every expert on every round is expensive. We present an algorithm for
advice-efficient prediction with expert advice that achieves
$O(\sqrt{\frac{N}{M}T\ln N})$ regret on $T$ rounds of the game.


title:
Universal fault-tolerant quantum computation with only transversal gates
  and error correction

abstract:
  Transversal implementations of encoded unitary gates are highly desirable for
fault-tolerant quantum computation. Though transversal gates alone cannot be
computationally universal, they can be combined with specially distilled
resource states in order to achieve universality. We show that "triorthogonal"
stabilizer codes, introduced for state distillation by Bravyi and Haah [Phys.
Rev. A 86 052329 (2012)], admit transversal implementation of the
controlled-controlled-Z gate. We then construct a universal set of
fault-tolerant gates without state distillation by using only transversal
controlled-controlled-Z, transversal Hadamard, and fault-tolerant error
correction. We also adapt the distillation procedure of Bravyi and Haah to
Toffoli gates, improving on existing Toffoli distillation schemes.


title: Weak and cyclic amenability for Fourier algebras of connected Lie groups

abstract:
  Using techniques of non-abelian harmonic analysis, we construct an explicit,
non-zero cyclic derivation on the Fourier algebra of the real $ax+b$ group. In
particular this provides the first proof that this algebra is not weakly
amenable. Using the structure theory of Lie groups, we deduce that the Fourier
algebras of connected, semisimple Lie groups also support non-zero, cyclic
derivations and are likewise not weakly amenable. Our results complement
earlier work of Johnson (JLMS, 1994), Plymen (unpublished note) and
Forrest--Samei--Spronk (IUMJ 2009). As an additional illustration of our
techniques, we construct an explicit, non-zero cyclic derivation on the Fourier
algebra of the reduced Heisenberg group, providing the first example of a
connected nilpotent group whose Fourier algebra is not weakly amenable.


title:
All order $\alpha'$ higher derivative corrections to non-BPS branes of
  type IIB Super string theory

abstract:
  By dealing with the evaluation of string theory correlators of $<V_C V_T
V_{\bar\Psi} V_\Psi>$, the complete and closed form of the amplitude of two
fermion fields, one tachyon and one closed string Ramond-Ramond field in type
IIB superstring theory is found. Specifically by comparing infinite tachyon
poles in field theory amplitude with infinite tachyon poles of the S-matrix of
string amplitude (for $p+1=n$ case), all the infinite higher derivative
corrections of two tachyons and two fermions (in type IIB) to all orders of
$\alpha'$ have been discovered. Using these new couplings, we are able to
produce infinite $t'+s'+u$-channel tachyon poles of string theory in field
theory. Due to internal degrees of freedom of fermions and tachyon (Chan-Paton
factors) we comment that, neither there should be single $s,t-$channel fermion
(tachyon pole) nor their infinite poles.
  Due to internal CP factor we also discover that there is no coupling between
two closed string Ramond-Ramond (RR) field and one tachyon in type II super
string theory.
  Taking into account the fact that the kinetic terms of fermions, gauge,
scalar fields and tachyons do not obtain any higher derivative corrections, and
due to their CP factors, string theory amplitude dictates us there should not
be any double poles in the amplitude of one RR, two fermions and one tachyon.


title:
Determination of z~0.8 neutral hydrogen fluctuations using the 21 cm
  intensity mapping auto-correlation

abstract:
  The large-scale distribution of neutral hydrogen in the Universe will be
luminous through its 21 cm emission. Here, for the first time, we use the
auto-power spectrum of 21 cm intensity fluctuations to constrain neutral
hydrogen fluctuations at z~0.8. Our data were acquired with the Green Bank
Telescope and span the redshift range 0.6 < z < 1 over two fields totalling ~41
deg. sq. and 190 h of radio integration time. The dominant synchrotron
foregrounds exceed the signal by ~10^3, but have fewer degrees of freedom and
can be removed efficiently. Even in the presence of residual foregrounds, the
auto-power can still be interpreted as an upper bound on the 21 cm signal. Our
previous measurements of the cross-correlation of 21 cm intensity and the
WiggleZ galaxy survey provide a lower bound. Through a Bayesian treatment of
signal and foregrounds, we can combine both fields in auto- and cross-power
into a measurement of Omega_HI b_HI = [0.62^{+0.23}_{-0.15}] * 10^{-3} at 68%
confidence with 9% systematic calibration uncertainty, where Omega_HI is the
neutral hydrogen (HI) fraction and b_HI is the HI bias parameter. We describe
observational challenges with the present data set and plans to overcome them.


title: Computational Nuclear Quantum Many-Body Problem: The UNEDF Project

abstract:
  The UNEDF project was a large-scale collaborative effort that applied
high-performance computing to the nuclear quantum many-body problem. UNEDF
demonstrated that close associations among nuclear physicists, mathematicians,
and computer scientists can lead to novel physics outcomes built on algorithmic
innovations and computational developments. This review showcases a wide range
of UNEDF science results to illustrate this interplay.


title: Towards the Minimum Inner Edge Distance of the Habitable Zone

abstract:
  We explore the minimum distance from a host star where an exoplanet could
potentially be habitable in order not to discard close-in rocky exoplanets for
follow-up observations. We find that the inner edge of the Habitable Zone for
hot desert worlds can be as close as 0.38 AU around a solar-like star, if the
greenhouse effect is reduced ($\sim$ 1% relative humidity) and the surface
albedo is increased. We consider a wide range of atmospheric and planetary
parameters such as the mixing ratios of greenhouse gases (water vapor and
CO$_2$), surface albedo, pressure and gravity. Intermediate surface pressure
($\sim$1-10 bars) is necessary to limit water loss and to simultaneously
sustain an active water cycle. We additionally find that the water loss
timescale is influenced by the atmospheric CO$_2$ level, because it indirectly
influences the stratospheric water mixing ratio. If the CO$_2$ mixing ratio of
dry planets at the inner edge is smaller than 10$^{-4}$, the water loss
timescale is $\sim$1 billion years, which is considered here too short for life
to evolve. We also show that the expected transmission spectra of hot desert
worlds are similar to an Earth-like planet. Therefore, an instrument designed
to identify biosignature gases in an Earth-like atmosphere can also identify
similarly abundant gases in the atmospheres of dry planets. Our inner edge
limit is closer to the host star than previous estimates. As a consequence, the
occurrence rate of potentially habitable planets is larger than previously
thought.


title: A resolution of the cosmic Lithium problem

abstract:
  In 1982, Monique and Francois Spite discovered that the 7Li abundance in the
atmosphere of old metal-poor dwarf stars in the galactic halo was independent
of metallicity and temperature. Since then, 7Li abundance in the Universe has
become a subject of intrigue, because there is less of it in Population II
dwarf stars (by a factor of 3) than standard big bang nucleosynthesis predicts.
Here we show how quark-novae (QNe) occurring in the wake of Pop. III stars, can
elegantly produce an A(Li) ~ 2.2 Lithium plateau in Pop. II (low-mass) stars
formed in the pristine cloud swept up by the mixed SN+QN ejecta. We also find
an increase in the scatter as well as an eventual drop in A(Li) below the Spite
plateau values for very low metallicity ([Fe/H] < -3) in excellent agreement
with observations. We propose a solution to the discrepancy between the Big
Bang Nucleosynthesis 7Li abundance and the Spite plateau and list some
implications and predictions of our model.


title: From Declarative Model to Solution: Scheduling Scenario Synthesis

abstract:
  This paper presents deductive programming for scheduling scenario generation.
Modeling for solution is achieved through program transformations. First,
declarative model for scheduling problem domain is introduced. After that model
is interpreted as scheduling domain language and as predicate transition Petri
net. Generated reachability tree presents search space with solutions. At the
end results are discussed and analyzed.


title:
Linking X-ray AGN with dark matter halos: a model compatible with AGN
  luminosity function and large-scale clustering properties

abstract:
  Our goal is to find a minimalistic model that describes the luminosity
function and large-scale clustering bias of the X-ray-selected AGN in the
general framework of the concordance LCDM model. We assume that a simple
population-averaged scaling relation between the AGN X-ray luminosity L_X and
the host dark matter halo mass M_h exists. With such a relation, the AGN X-ray
luminosity function can be computed from the halo mass function. Using the
concordance LCDM halo mass function for the latter, we obtain the M_h-L_X
relation required to match the redshift-dependent AGN X-ray luminosity function
known from X-ray observations. We find that with a simple power-law-scaling M_h
\propto L_X^\Gamma(z), our model can successfully reproduce the observed X-ray
luminosity function. Furthermore, we automatically obtain predictions for the
large-scale AGN clustering amplitudes and their dependence on the luminosity
and redshift, which seem to be compatible with AGN clustering measurements. Our
model also includes the redshift-dependent AGN duty cycle which peaks at the
redshift z ~ 1, and its peak value is consistent with unity, suggesting that on
average there is no more than one AGN per dark matter halo. For a typical
X-ray-selected AGN at z ~ 1, our best-fit M_h-L_X scaling implies low Eddington
ratio L_X/L_Edd ~ 10^{-4}-10^{-3} (2-10 keV band, no bolometric correction
applied) and correspondingly large mass growth e-folding times, suggesting that
the typical X-ray AGN are dominantly fueled via relatively inefficient
'hot-halo' accretion mode.


title:
Quantum symmetry groups of Hilbert modules equipped with orthogonal
  filtrations

abstract:
  We define and show the existence of the quantum symmetry group of a Hilbert
module equipped with an orthogonal filtration. Our construction unifies the
constructions of Banica-Skalski's quantum symmetry group of a C*-algebra
equipped with an orthogonal filtration and Goswami's quantum isometry group of
an admissible spectral triple.


title: Emergence of Quantum Mechanics from a Sub-Quantum Statistical Mechanics

abstract:
  A research program within the scope of theories on "Emergent Quantum
Mechanics" is presented, which has gained some momentum in recent years. Via
the modeling of a quantum system as a non-equilibrium steady-state maintained
by a permanent throughput of energy from the zero-point vacuum, the quantum is
considered as an emergent system. We implement a specific "bouncer-walker"
model in the context of an assumed sub-quantum statistical physics, in analogy
to the results of experiments by Couder's group on a classical wave-particle
duality. We can thus give an explanation of various quantum mechanical features
and results on the basis of a "21st century classical physics", such as the
appearance of Planck's constant, the Schr\"odinger equation, etc. An essential
result is given by the proof that averaged particle trajectories' behaviors
correspond to a specific type of anomalous diffusion termed "ballistic"
diffusion on a sub-quantum level. It is further demonstrated both analytically
and with the aid of computer simulations that our model provides explanations
for various quantum effects such as double-slit or n-slit interference. We show
the averaged trajectories emerging from our model to be identical to Bohmian
trajectories, albeit without the need to invoke complex wave functions or any
other quantum mechanical tool. Finally, the model provides new insights into
the origins of entanglement, and, in particular, into the phenomenon of a
"systemic" nonlocality.


title: R0 and the elimination of HIV in Africa: Will 90-90-90 be sufficient?

abstract:
  The Joint United Nations Programme on HIV and AIDS (UNAIDS) has set a new
90-90-90 global target for the coverage of anti-retroviral therapy (ART) to be
reached by 2020. This would mean that 90% of all people infected with HIV know
their status, 90% of them are on ART and 90% of them will have full viral load
suppression. Here we first estimate the case reproduction number, R0, for
countries in sub-Saharan Africa and for India using data on the rate at which
the prevalence of HIV increased at the start of the epidemic and the life
expectancy of people living with HIV who are not on ART. R0 determines the
magnitude of the control problem, that is to say, the extent to which
transmission must be reduced to eliminate HIV. We show that in sub-Saharan
Africa the median value of R0 is 4.6 and in all but five countries R0 is less
than 6.3. If the 90-90-90 target is reached, 73% of all those living with HIV
will have full viral load suppression. If this is maintained it should
guarantee elimination in 70% of all countries in sub-Saharan Africa and will
reduce R0 to less than 2 in the remaining 12 countries, making elimination easy
to achieve by increasing the availability of other high impact methods of
prevention.


title: Physics at CERN's Antiproton Decelerator

abstract:
  The Antiproton Decelerator of CERN began operation in 1999 to serve
experiments for studies of CPT invariance by precision laser and microwave
spectroscopy of antihydrogen ($\bar{\rm H}$) and antiprotonic helium
($\bar{p}{\rm He}^+$). The first 12 years of operation saw cold $\bar{\rm H}$
synthesized by overlapping clouds of positrons ($e^+$) and antiprotons
($\bar{p}$) confined in magnetic Penning traps. Cold $\bar{\rm H}$ was also
produced in collisions between Rydberg positronium atoms and $\bar{p}$.
Ground-state $\bar{\rm H}$ was later trapped for up to $\sim 1000$ s in a
magnetic bottle trap, and microwave transitions excited between its hyperfine
levels. In the $\bar{p}{\rm He}^+$ atom, UV transitions were measured to a
precision of (2.3-5) $\times$ $10^{-9}$ by sub-Doppler two-photon laser
spectroscopy. From this the antiproton-to-electron mass ratio was determined as
$M_{\bar{p}}/m_e=$1836.1526736(23), which agrees with the p value. Microwave
spectroscopy of $\bar{p}{\rm He}^+$ yielded a measurement of the $\bar{p}$
magnetic moment with a precision of 0.3%. More recently the magnetic moment of
a single $\bar{p}$ confined in a Penning trap was measured with a higher
precision, as $\mu_{\bar{p}}=-2.792845(12)$$\mu_{\rm nucl}$ in nuclear
magnetons. Other measurements include the energy loss of 1-100 keV $\bar{p}$
traversing conductor and insulator targets; the cross sections of <10 keV
$\bar{p}$ ionizing gas targets; and the cross sections of 5-MeV $\bar{p}$
annihilating on target foils via nuclear collisions. The biological
effectiveness of $\bar{p}$ beams destroying cancer cells was measured as a
possible method for radiological therapy. New experiments under preparation
attempt to measure the gravitational acceleration of $\bar{\rm H}$ or
synthesize $\obar{\rm H}^+$.


title:
Hierarchy of Frustrations as Supplementary Indices in Complex System
  Dynamics, Applied to the U.S. Intermarket

abstract:
  Definition of frustration is expressed by transitivity of binary entanglement
relation in considered complex system. Extending this definition into n-ary
relation a hierarchy of frustrations is derived. As a complex system the U.S.
Intermarket is chosen where the correlation coefficient of intermarket sectors
plays the role of entanglement measure. In each hierarchy level the frustration
and the transitivity are interpreted as values of an order of measure for
corresponding subsystem. The derived theory is applied to 1983-2012 data of the
U.S. Intermarket.


title:
Space group symmetry, spin-orbit coupling and the low energy effective
  Hamiltonian for iron based superconductors

abstract:
  We construct the symmetry adapted low energy effective Hamiltonian for the
electronic states in the vicinity of the Fermi level in iron based
superconductors. We use Luttinger's method of invariants, expanding about Gamma
and M points in the Brillouin zone corresponding to two iron unit cell, and
then matching the coefficients of the expansion to the 5- and 8-band models. We
then use the method of invariants to study the effects of the spin-density wave
order parameters on the electronic spectrum, with and without spin-orbit
coupling included. Among the results of this analysis is the finding that the
nodal spin-density wave is unstable once spin-orbit coupling is included.
Similar analysis is performed for the A_{1g} spin singlet superconducting
state. Without spin-orbit coupling there is one pairing invariant near the
Gamma point, but two near the M point. This leads to an isotropic spectral gap
at the hole Fermi surface near Gamma, but anisotropic near M. The relative
values of these three parameters determine whether the superconducting state is
s_{++}, s_{+-}, or nodal. Inclusion of spin-orbit coupling leads to additional
mixing of spin triplet pairing, with one additional pairing parameter near
Gamma and one near M. This leads to an anisotropic spectral gap near both hole
and electron Fermi surfaces, the latter no longer cross, but rather split.


title: New Constraints on the Early Expansion History

abstract:
  Cosmic microwave background measurements have pushed to higher resolution,
lower noise, and more sky coverage. These data enable a unique test of the
early universe's expansion rate and constituents such as effective number of
relativistic degrees of freedom and dark energy. Using the most recent data
from Planck and WMAP9, we constrain the expansion history in a model
independent manner from today back to redshift z=10^5. The Hubble parameter is
mapped to a few percent precision, limiting early dark energy and extra
relativistic degrees of freedom within a model independent approach to 2-16%
and 0.71 equivalent neutrino species respectively (95% CL). Within dark
radiation, barotropic aether, and Doran-Robbers models, the early dark energy
constraints are 3.3%, 1.9%, 1.2% respectively.


title:
Duality and Higher Temperature Phases of Large $N$ Chern-Simons Matter
  Theories on $S^2 \times S^1$

abstract:
  It has been recently demonstrated that the thermal partition function of any
large $N$ Chern-Simons gauge theories on $S^2$, coupled to fundamental matter,
reduces to a capped unitary matrix model. The matrix models corresponding to
several specific matter Chern-Simons theories at temperature $T$ were
determined in arXiv:1301.6169. The large $N$ saddle point equations for these
theories were determined in the same paper, and were solved in the low
temperature phase. In this paper we find exact solutions for these saddle point
equations in three other phases of these theories and thereby explicitly
determine the free energy of the corresponding theories at all values of
$T^2/N$. As anticipated on general grounds in arXiv:1301.6169, our results are
in perfect agreement with conjectured level rank type bosonization dualities
between pairs of such theories.


title: Are z~5 QSOs found in the most massive high redshift over-densities?

abstract:
  Luminous high-redshift QSOs are thought to exist within the most massive dark
matter haloes in the young Universe. As a consequence they are likely to be
markers for biased, over-dense regions where early galaxies cluster, regions
that eventually grow into the groups and clusters seen in the lower redshift
universe. In this paper we explore the clustering of galaxies around z ~ 5 QSOs
as traced by Lyman Break Galaxies (LBGs). We target the fields of three QSOs
using the same optical imaging and spectroscopy techniques used in the ESO
Remote Galaxy Survey (ERGS, Douglas et al. 2009, 2010), which was successful in
identifying individual clustered structures of LBGs. We use the statistics of
the redshift clustering in ERGS to show that two of the three fields show
significant clustering of LBGs at the QSO redshifts. Neither of these fields is
obviously over-dense in LBGs from the imaging alone; a possible reason why
previous imaging-only studies of high-redshift QSO environments have given
ambiguous results. This result shows that luminous QSOs at z ~ 5 are typically
found in over-dense regions. The richest QSO field contains at least nine
spectroscopically confirmed objects at the same redshift including the QSO
itself, seven LBGs and a second fainter QSO. While this is a very strong
observational signal of clustering at z ~ 5, it is of similar strength to that
seen in two structures identified in the 'blank sky' ERGS fields. This
indicates that, while over-dense, the QSO environments are not more extreme
than other structures that can be identified at these redshifts. The three
richest structures discovered in this work and in ERGS have properties
consistent with that expected for proto-clusters and likely represent the early
stages in the build-up of massive current-day groups and clusters.


title:
Gyro-gauge-independent formulation of the guiding-center reduction to
  arbitrary order in the Larmor radius

abstract:
  The guiding-center reduction is studied using gyro-gauge-independent
coordinates. The Lagrangian 1-form of charged particle dynamics is Lie
transformed without introducing a gyro-gauge, but using directly the unit
vector of the component of the velocity perpendicular to the magnetic field as
the coordinate corresponding to Larmor gyration. The reduction is shown to
provide a maximal reduction for the Lagrangian and to work to all orders in the
Larmor radius, following exactly the same procedure as when working with the
standard gauge-dependent coordinate. The gauge-dependence is removed from the
coordinate system by using a constrained variable for the gyro-angle. The
closed 1-form d teta is replaced by a more general non-closed 1-form, which is
equal to d theta in the gauge-dependent case. The gauge vector is replaced by a
more general connection in the definition of the gradient, which behaves as a
covariant derivative, in perfect agreement with the circle-bundle picture. This
explains some results of previous works, whose gauge-independent expressions
did not correspond to a gauge fixing but indeed correspond to a connection
fixing. In addition, some general results are obtained for the guiding-center
reduction. The expansion is polynomial in the cotangent of the pitch-angle as
an effect of the structure of the Lagrangian, preserved by Lie derivatives. The
induction for the reduction is shown to rely on the inversion of a matrix which
is the same for all orders higher than three. It is inverted and explicit
induction relations are obtained to go to arbitrary order in the perturbation
expansion. The Hamiltonian and symplectic representations of the guiding-center
reduction are recovered, but conditions for the symplectic representation at
each order are emphasized.


title:
Factorisation of laser pulse ionisation probabilities in the
  multiphotonic regime

abstract:
  We present a detailed study of the ionisation probability of H and
H$_{2}^{+}$ induced by a short intense laser pulse. Starting from a
Coulomb-Volkov description of the process we derive a multipole-like expansion
where each term is factored into two contributions: one that accounts for the
effect of the electromagnetic field on the free-electron final-state and a
second factor that depends only on the target structure. Such a separation may
be valuable to solve complex atomic or molecular systems as well as to
interpret the dynamics of the process in simpler terms. We show that the series
expansion converges rapidly, and thus the inclusion of the first few terms are
sufficient to produce accurate results.