title:
Structural variations and magnetic properties of the quantum
  antiferromagnets Cs2CuCl4-xBrx

abstract:
  Depending on the crystal growth conditions, an orthorhombic (O-type) or a
tetragonal (T-type) structure can be found in the solid solution Cs2CuCl4-xBrx
(0 < x < 4). Here we present measurements of the temperature-dependent magnetic
susceptibility and isothermal magnetization on the T-type compounds x = 1.6 and
1.8 and compare these results with the magnetic properties recently derived for
the O-type variant by Cong et al., Phys. Rev. B 83, 064425 (2011). The systems
were found to exhibit quite dissimilar magnetic properties which can be
assigned to differences in the Cu coordination in these two structural
variants. Whereas the tetragonal compounds can be classified as quasi-2D
ferromagnets, characterized by ferromagnetic layers with a weak
antiferromagnetic inter-layer coupling, the orthorhombic materials, notably the
border compounds x = 0 and 4, are model systems for frustrated 2D Heisenberg
antiferromagnets


title: Evolutionary tracks of massive stars during formation

abstract:
  A model for massive stars is constructed by piecing together evolutionary
algorithms for the protostellar structure, the environment, the inflow and the
radiation feedback. We investigate specified accretion histories of constant,
decelerating and accelerating forms and consider both hot and cold accretion,
identified with spherical free-fall and disk accretion, respectively.
Diagnostic tools for the interpretation of the phases of massive star formation
and testing the evolutionary models are then developed. Evolutionary tracks
able to fit Herschel Space Telescope data require the generated stars to be
three to four times less massive than in previous interpretations, thus being
consistent with clump star formation efficiencies of $10 -- 15\%$. However, for
these cold Hershel clumps, the bolometric temperature is not a good diagnostic
to differentiate between accretion models. We also find that neither spherical
nor disk accretion can explain the high radio luminosities of many protostars.
Nevertheless, we discover a solution in which the extreme ultraviolet flux
needed to explain the radio emission is produced if the accretion flow is via
free-fall on to hot spots covering less than $10\%$ of the surface area.
Moreover, the protostar must be compact, and so has formed through cold
accretion. We show that these conclusions are independent of the imposed
accretion history. This suggests that massive stars form via gas accretion
through disks which, in the phase before the star bloats, download their mass
via magnetic flux tubes on to the protostar.


title: SUNNY: a Lazy Portfolio Approach for Constraint Solving

abstract:
  *** To appear in Theory and Practice of Logic Programming (TPLP) ***
  Within the context of constraint solving, a portfolio approach allows one to
exploit the synergy between different solvers in order to create a globally
better solver. In this paper we present SUNNY: a simple and flexible algorithm
that takes advantage of a portfolio of constraint solvers in order to compute
--- without learning an explicit model --- a schedule of them for solving a
given Constraint Satisfaction Problem (CSP). Motivated by the performance
reached by SUNNY vs. different simulations of other state of the art
approaches, we developed sunny-csp, an effective portfolio solver that exploits
the underlying SUNNY algorithm in order to solve a given CSP. Empirical tests
conducted on exhaustive benchmarks of MiniZinc models show that the actual
performance of SUNNY conforms to the predictions. This is encouraging both for
improving the power of CSP portfolio solvers and for trying to export them to
fields such as Answer Set Programming and Constraint Logic Programming.


title: Orbifold equivalent potentials

abstract:
  To a graded finite-rank matrix factorisation of the difference of two
homogeneous potentials one can assign two numbers, the left and right quantum
dimension. The existence of such a matrix factorisation with non-zero quantum
dimensions defines an equivalence relation between potentials, giving rise to
non-obvious equivalences of categories.
  Restricted to ADE singularities, the resulting equivalence classes of
potentials are those of type {A_{d-1}} for d odd, {A_{d-1},D_{d/2+1}} for d
even but not in {12,18,30}, and {A_{11}, D_7, E_6}, {A_{17}, D_{10}, E_7} and
{A_{29}, D_{16}, E_8}. This is the result expected from two-dimensional
rational conformal field theory, and it directly leads to new descriptions of
and relations between the associated (derived) categories of matrix
factorisations and Dynkin quiver representations.


title:
HINO: a BFO-aligned ontology representing human molecular interactions
  and pathways

abstract:
  Many database resources, such as Reactome, collect manually annotated
reactions, interactions, and pathways from peer-reviewed publications. The
interactors (e.g., a protein), interactions, and pathways in these data
resources are often represented as instances in using BioPAX, a standard
pathway data exchange format. However, these interactions are better
represented as classes (or universals) since they always occur given
appropriate conditions. This study aims to represent various human interaction
pathways and networks as classes via a formal ontology aligned with the Basic
Formal Ontology (BFO). Towards this goal, the Human Interaction Network
Ontology (HINO) was generated by extending the BFO-aligned Interaction Network
Ontology (INO). All human pathways and associated processes and interactors
listed in Reactome and represented in BioPAX were first converted to ontology
classes by aligning them under INO. Related terms and associated relations and
hierarchies from external ontologies (e.g., CHEBI and GO) were also retrieved
and imported into HINO. HINO ontology terms were resolved in the linked
ontology data server Ontobee. The RDF triples stored in the RDF triple store
are queryable through a SPARQL program. Such an ontology system supports
advanced pathway data integration and applications.


title:
Global analysis of the negative parity non-strange baryons in the 1/Nc
  expansion

abstract:
  A global study of the negative parity non-strange baryon observables is
performed in the frame- work of the 1/Nc expansion. Masses, partial decay
widths and photo-couplings are simultaneously analyzed. A main objective is to
determine the composition of the spin 1/2 and 3/2 nucleon states, which come in
pairs and involve two mixing angles which can be determined and tested for
consistency by the mentioned observables. The issue of the assignment of those
nucleon states to the broken SU(4) x O(3) mixed-symmetry multiplet is studied
in detail, with the conclusion that the assignment made in the old studies
based on the non-relativistic quark model is the preferred one. In addition,
the analysis involves an update of the input data with respect to previous
works.


title:
Stereographical visualization of a polarization state using weak
  measurements with an optical-vortex beam

abstract:
  We propose a stereographical-visualization scheme for a polarization state by
two-dimensional imaging of a weak value with a single setup. The key idea is to
employ Laguerre-Gaussian modes or an optical vortex beam for a probe state in
weak measurement. Our scheme has the advantage that we can extract information
on the polarization state from the single image in which the zero-intensity
point of the optical vortex beam corresponds to a stereographic projection
point of the Poincare sphere. We experimentally perform single-setup weak
measurement to validate the stereographical relationship between the
polarization state on the Poincare sphere and the location of the
zero-intensity point.


title: Generating Equidistributed Meshes in 2D via Domain Decomposition

abstract:
  In this paper we consider Schwarz domain decomposition applied to the
generation of 2D spatial meshes by a local equidistribution principle. We
briefly review the derivation of the local equidistribution principle and the
appropriate choice of boundary conditions. We then introduce classical and
optimized Schwarz domain decomposition methods to solve the resulting system of
nonlinear equations. The implementation of these iterations are discussed, and
we conclude with numerical examples to illustrate the performance of the
approach.


title: The morphing of fluid queues into Markov-modulated Brownian motion

abstract:
  Ramaswami showed recently that standard Brownian motion arises as the limit
of a family of Markov-modulated linear fluid processes. We pursue this analysis
with a fluid approximation for Markov-modulated Brownian motion. Furthermore,
we prove that the stationary distribution of a Markov-modulated Brownian motion
reflected at zero is the limit from the well-analyzed stationary distribution
of approximating linear fluid processes. Key matrices in the limiting
stationary distribution are shown to be solutions of a new quadratic equation,
and we describe how this equation can be efficiently solved. Our results open
the way to the analysis of more complex Markov-modulated processes.


title:
The IACOB project: I. Rotational velocities in Northern Galactic O and
  early B-type stars revisited. The impact of other sources of line-broadening

abstract:
  Stellar rotation is an important parameter in the evolution of massive stars.
Accurate and reliable measurements of projected rotational velocities in large
samples of OB stars are crucial to confront the predictions of stellar
evolutionary models with observational constraints. We reassess previous
determinations of projected rotational velocities (vsini) in Galactic OB stars
using a large, high quality spectroscopic dataset, and a strategy which account
for other sources of broadening appart from rotation affecting the diagnostic
lines We present a versatile and user friendly IDL tool, based on a combined
Fourier Transform (FT) + goodness of fit (GOF) methodology, for the
line-broadening characterization in OB-type stars. We use this tool to (a)
investigate the impact of macroturbulent and microturbulent broadenings on
vsini measurements, and (b) determine vsini in a sample of 200 Galactic OB-type
stars, also characterizing the amount of macroturbulent broadening (\vmacro)
affecting the line profiles. We present observational evidence illustrating the
strengths and limitations of the proposed FT+GOF methodology for the case of OB
stars. We confirm previous statements (based on indirect arguments or smaller
samples) that the macroturbulent broadening is ubiquitous in the massive star
domain. We compare the newly derived vsini with previous determinations not
accounting for this extra line-broadening contribution, and show that those
cases with vsini< 120 km/s need to be systematically revised downwards by ~25
(+/-20) km/s. We suggest that microturbulence may impose an upper limit below
which vsini and \vmacro\ could be incorrectly derived by means of the proposed
methodology as presently used, and discuss the implications of this statement
on the study of relatively narrow line massive stars.


title: Chromo-Natural Model in Anisotropic Background

abstract:
  In this work we study the chromo-natural inflation model in the anisotropic
setup. Initiating inflation from Bianchi type-I cosmology, we analyze the
system thoroughly during the slow-roll inflation, from both analytical and
numerical points of view. We show that the isotropic FRW inflation is an
attractor of the system. In other words, anisotropies are damped within few
$e$--folds and the chromo-natural model respects the cosmic no-hair conjecture.
Furthermore, we demonstrate that in the slow-roll limit, the anisotropies in
both chromo-natural and gauge-flation models share the same dynamics.


title: Some non-contracting automata groups

abstract:
  We add to the classification of groups generated by 3-state automata over a 2
letter alphabet given by Bondarenko et al., by showing that a number of the
groups in the classification are non-contracting. We show that the criterion we
use to prove a self-similar action is non-contracting also implies that the
associated self-similarity graph introduced by Nekrashevych is non-hyperbolic.


title: Boundaries of planar graphs, via circle packings

abstract:
  We provide a geometric representation of the Poisson and Martin boundaries of
a transient, bounded degree triangulation of the plane in terms of its circle
packing in the unit disc. (This packing is unique up to M\"obius
transformations.) More precisely, we show that any bounded harmonic function on
the graph is the harmonic extension of some measurable function on the boundary
of the disk, and that the space of extremal positive harmonic functions, that
is, the Martin boundary, is homeomorphic to the unit circle. All our results
hold more generally for any "good"-embedding of planar graphs, that is, an
embedding in the unit disc with straight lines such that angles are bounded
away from $0$ and $\pi$ uniformly, and lengths of adjacent edges are
comparable. Furthermore, we show that in a good embedding of a planar graph the
probability that a random walk exits a disc through a sufficiently wide arc is
at least a constant, and that Brownian motion on such graphs takes time of
order $r^2$ to exit a disc of radius $r$. These answer a question recently
posed by Chelkak (2014).


title:
Extending robustness & randomization from Consensus to Symmetrization
  Algorithms

abstract:
  This work interprets and generalizes consensus-type algorithms as switching
dynamics leading to symmetrization of some vector variables with respect to the
actions of a finite group. We show how the symmetrization framework we develop
covers applications as diverse as consensus on probability distributions
(either classical or quantum), uniform random state generation, and open-loop
disturbance rejection by quantum dynamical decoupling. Robust convergence
results are explicitly provided in a group-theoretic formulation, both for
deterministic and for randomized dynamics. This indicates a way to directly
extend the robustness and randomization properties of consensus-type algorithms
to more fields of application.


title: Deriving the Qubit from Entropy Principles

abstract:
  The Heisenberg uncertainty principle is one of the most famous features of
quantum mechanics. However, the non-determinism implied by the Heisenberg
uncertainty principle --- together with other prominent aspects of quantum
mechanics such as superposition, entanglement, and nonlocality --- poses deep
puzzles about the underlying physical reality, even while these same features
are at the heart of exciting developments such as quantum cryptography,
algorithms, and computing. These puzzles might be resolved if the mathematical
structure of quantum mechanics were built up from physically interpretable
axioms, but it is not. We propose three physically-based axioms which together
characterize the simplest quantum system, namely the qubit. Our starting point
is the class of all no-signaling theories. Each such theory can be regarded as
a family of empirical models, and we proceed to associate entropies, i.e.,
measures of information, with these models. To do this, we move to phase space
and impose the condition that entropies are real-valued. This requirement,
which we call the Information Reality Principle, arises because in order to
represent all no-signaling theories (including quantum mechanics itself) in
phase space, it is necessary to allow negative probabilities (Wigner [1932]).
Our second and third principles take two important features of quantum
mechanics and turn them into deliberately chosen physical axioms. One axiom is
an Uncertainty Principle, stated in terms of entropy. The other axiom is an
Unbiasedness Principle, which requires that whenever there is complete
certainty about the outcome of a measurement in one of three mutually
orthogonal directions, there must be maximal uncertainty about the outcomes in
each of the two other directions.


title:
Radiative transition processes of light vector resonances in a chiral
  framework

abstract:
  Within the framework of chiral effective field theory, we study various
electromagnetic processes with light vector resonances: $K^{\ast}(892)\to
K\gamma$, $e^{+}e^{-}\to K^{\ast}(892)K $ and the $\omega\pi\gamma^\ast$ form
factors. With two multiplets of vector resonances being introduced, we fit the
decay widths of $K^{\ast0}\to K^{0}\gamma$, $K^{\ast+}\to K^{+}\gamma$, and the
pertinent measurements from the $e^{+}e^{-}\to K^{\ast \pm}(892)K^{\mp} $ cross
sections, such as moduli and relative phases between the isoscalar and
isovector components from BABAR collaboration, together with the $\omega\pi$
form factors from NA60, SND and CLEO collaborations. The values of resonance
couplings, masses and widths of the excited vector states $\rho'$ and $\phi'$
are then determined. The $\omega'$-$\phi'$ mixing angle is discussed and turns
out to be quite different from the ideal mixing case. Three sources of $SU(3)$
symmetry breaking effects in the $\Gamma(K^{\ast}\to K\gamma)$ decays are
identified and analyzed in detail.


title: Remarks on Li-Yau inequality on graphs

abstract:
  In this paper, we study Li-Yau gradient estimates for the solutions $u$ to
the heat equation $\partial_tu=\Delta u$ on graphs under the curvature
condition $CD(n,-K)$ introduced by Bauer et al. in \cite{BHLLMY}. As
applications, we derive Harnack inequalities and heat kernel estimates on
graphs. Also we present a type of Hamilton gradient estimates.


title: Anytime Belief Propagation Using Sparse Domains

abstract:
  Belief Propagation has been widely used for marginal inference, however it is
slow on problems with large-domain variables and high-order factors. Previous
work provides useful approximations to facilitate inference on such models, but
lacks important anytime properties such as: 1) providing accurate and
consistent marginals when stopped early, 2) improving the approximation when
run longer, and 3) converging to the fixed point of BP. To this end, we propose
a message passing algorithm that works on sparse (partially instantiated)
domains, and converges to consistent marginals using dynamic message
scheduling. The algorithm grows the sparse domains incrementally, selecting the
next value to add using prioritization schemes based on the gradients of the
marginal inference objective. Our experiments demonstrate local anytime
consistency and fast convergence, providing significant speedups over BP to
obtain low-error marginals: up to 25 times on grid models, and up to 6 times on
a real-world natural language processing task.


title: Renormalization and Scaling in Quantum Walks

abstract:
  We show how to extract the scaling behavior of quantum walks using the
renormalization group (RG). We introduce the method by efficiently reproducing
well-known results on the one-dimensional lattice. As a nontrivial model, we
apply this method to the dual Sierpinski gasket and obtain its exact, closed
system of RG-recursions. Numerical iteration suggests that under rescaling the
system length, $L^{\prime}=2L$, characteristic times rescale as
$t^{\prime}=2^{d_{w}}t$ with the exact walk exponent
$d_{w}=\log_{2}\sqrt{5}=1.1609\ldots$. Despite the lack of translational
invariance, this is very close to the ballistic spreading, $d_{w}=1$, found for
regular lattices. However, we argue that an extended interpretation of the
traditional RG formalism will be needed to obtain scaling exponents
analytically. Direct simulations confirm our RG-prediction for $d_w$ and
furthermore reveal an immensely rich phenomenology for the spreading of the
quantum walk on the gasket. Invariably, quantum interference localizes the walk
completely with a site-access probability that declines with a powerlaw from
the initial site, in contrast with a classical random walk, which would pass
all sites with certainty.


title: Experimental overview of charmonium spectroscopy

abstract:
  In this talk, I review the recent experimental results on charmonium
spectroscopy from BESIII, Belle, BaBar and CLEOc. Below the open-charm
threshold, the masses and widths of spin-singlet states eta_c, eta_c(2S), h_c
are measured with high precision. Above the threshold, chi_{c2}(2P) is
identified in the process gamma gamma -> chi_{c2}(2P) -> gamma D bar{D};
Evidence of X(3823) is found in the M(chi_{c1} gamma) invariant-mass
distribution for B -> gamma chi_{c1} K decays, the measured properties are
consistent with the missing psi_2(1^{2}D_2) state.


title: Android Note Manager Application for People with Visual Impairment

abstract:
  With the outburst of smart-phones today, the market is exploding with various
mobile applications. This paper proposes an application using which visually
impaired people can type a note in Grade 1 Braille and save it in the external
memory of their smart-phone. The application also shows intelligence by
activating reminders and/or calling certain contacts based on the content in
the notes.


title:
Predictions for the Detection of Earth and Mars Trojan Asteroids by the
  Gaia satellite

abstract:
  The European Space Agency Gaia satellite, planned for launch in late 2013,
will perform systematic astrometric observations of the whole sky over a five
year period. During this mission many thousands of Solar System Objects down to
magnitude V=20 will be observed including Near-Earth Asteroids and objects at
Solar elongations as low as 45 degrees, which are difficult to observe with
ground-based telescopes. We simulated the detection of Trojan asteroids in the
orbits of Earth and Mars by Gaia. We find that Gaia will not detect the Earth
Trojan 2010 TK7 although it will detect any Earth Trojans with diameters larger
than 600 m. We also find that Gaia will detect the currently known Mars Trojans
and could discover more than 100 new Mars Trojans as small as 400 m in
diameter. The results of the Gaia mission will test the predictions about the
Mars Trojan asteroid population and lead to greater understanding about the
evolution of the Solar System.


title: Zero-Field In-Plane Critical Current Density of YBa2Cu3O7-d Thin Films

abstract:
  Temperature dependence of the zero-field critical current density, Jc0(T), in
the CuO2 planes has been investigated for c-axis oriented YBa2Cu3O7-d (Y123)
thin films with different hole content, p. p-values were varied by changing the
oxygen deficiency, d. Jc0(T) were calculated from the magnetic hysteresis (M-H)
loops obtained at different temperatures. From the analysis of the Jc0(T) data
for different sample compositions, we have extracted valuable information
regarding the nature of the underlying magnetic flux pinning mechanisms in Y123
superconductors. It is found that the oxygen defects play only a secondary role
in pinning of the vortices, the superfluid density, on the other hand plays a
significant role. The temperature exponent, n, governing the Jc0(T) behavior
for a given sample composition showed a systematic behavior as hole contents
are changed.


title: A Bcool magnetic snapshot survey of solar-type stars

abstract:
  Stellar magnetic field measurements obtained from spectropolarimetry offer
key data for activity and dynamo studies, and we present the results of a major
high-resolution spectropolarimetric Bcool project magnetic snapshot survey of
170 solar-type stars from observations with the Telescope Bernard Lyot and the
Canada-France-Hawaii Telescope. For each target star a high signal-to-noise
circularly polarised Stokes V profile has been obtained using Least-Squares
Deconvolution, and used to detect surface magnetic fields and measure the
corresponding mean surface longitudinal magnetic field ($B_{l}$). Chromospheric
activity indicators were also measured.
  Surface magnetic fields were detected for 67 stars, with 21 of these stars
classified as mature solar-type stars, a result that increases by a factor of
four the number of mature solar-type stars on which magnetic fields have been
observed. In addition, a magnetic field was detected for 3 out of 18 of the
subgiant stars surveyed. For the population of K-dwarfs the mean value of
$B_{l}$ ($|B_{l}|_{mean}$) was also found to be higher (5.7 G) than
$|B_{l}|_{mean}$ measured for the G-dwarfs (3.2 G) and the F-dwarfs (3.3 G).
For the sample as a whole $|B_{l}|_{mean}$ increases with rotation rate and
decreases with age, and the upper envelope for $|B_{l}|$ correlates well with
the observed chromospheric emission. Stars with a chromospheric S-index greater
than about 0.2 show a high magnetic field detection rate and so offer optimal
targets for future studies.
  This survey constitutes the most extensive spectropolarimetric survey of cool
stars undertaken to date, and suggests that it is feasible to pursue magnetic
mapping of a wide range of moderately active solar-type stars to improve
understanding of their surface fields and dynamos.


title: Monitoring of multi-frequency polarization of gamma-ray bright AGNs

abstract:
  We started two observing programs with the Korean VLBI Network (KVN)
monitoring changes in the flux density and polarization of relativistic jets in
gamma-ray bright AGNs simultaneously at 22, 43, 86, 129 GHz. One is a
single-dish weekly-observing program in dual polarization with KVN 21-m
diameter radio telescopes beginning in 2011 May. The other is a VLBI
monthly-observing program with the three-element VLBI network at an angular
resolution range of 1.0--9.2 mas beginning in 2012 December. The monitoring
observations aim to study correlation of variability in gamma-ray with that in
radio flux density and polarization of relativistic jets when they flare up.
These observations enable us to study the origin of the gamma-ray flares of
AGNs.


title: TeV gamma-ray survey of the Northern sky using the ARGO-YBJ detector

abstract:
  The ARGO-YBJ detector is an extensive air shower array that has been used to
monitor the northern $\gamma$-ray sky at energies above 0.3 TeV from 2007
November to 2013 January. In this paper, we present the results of a sky survey
in the declination band from $-10^{\circ}$ to $70^{\circ}$, using data recorded
over the past five years. With an integrated sensitivity ranging from 0.24 to
$\sim$1 Crab units depending on the declination, six sources have been detected
with a statistical significance greater than 5 standard deviations. Several
excesses are also reported as potential $\gamma$-ray emitters. The features of
each source are presented and discussed. Additionally, $95\%$ confidence level
upper limits of the flux from the investigated sky region are shown. Specific
upper limits for 663 GeV $\gamma$-ray AGNs inside the ARGO-YBJ field of view
are reported. The effect of the absorption of $\gamma$-rays due to the
interaction with extragalactic background light is estimated.


title:
Examining resonant inelastic spontaneous scattering of classical
  Laguerre-Gauss beams from molecules

abstract:
  This paper theoretically treats the spontaneous resonant inelastic scattering
of Laguerre-Gauss (LG) beams from the totally symmetric vibrations of complex
polyatomic molecules within the semi-classical framework. We develop an
interaction Hamiltonian that accounts for the position of the molecule within
the excitation beam to derive the effective differential scattering
cross-section of a classical LG beam from a molecule using the frequency domain
third order nonlinear optical response function. To gain physical insight into
this scattering process, we utilize a model vibronic molecule to study the
changes to this scattering process. For specific molecular parameters including
vibrational frequency and relative displacement of the involved electronic
states, this investigation shows that an incident LG beam asymmetrically
enhances one of two participating excitation transitions causing modulation of
the interference present in the scattering process. This modulation allows a
pathway to coherent control of resonant inelastic scattering from complex,
poly-atomic molecules. We discuss the possible application of this control to
the resonant x-ray inelastic scattering (RIXS) of small poly-atomic molecules
central to applications ranging from single molecule electronics to solar
energy science.


title: Intrinsic Brightness Temperature of Compact Radio Sources at 86 GHz

abstract:
  We present results on the intrinsic brightness temperature of a sample of
compact radio sources observed at 86 GHz using the Global Millimeter VLBI
Array. We use the observed brightness temperatures at 86 GHz and the observed
superluminal motions at 15 GHz for the sample in order to constrain the
characteristic intrinsic brightness temperature of the sample. With a
statistical method for studying the intrinsic brightness temperatures of
innermost jet cores of compact radio sources, assuming that all sources have
the same intrinsic brightness temperature and the viewing angles of their jets
are around the critical value for the maximal apparent speed, we find that
sources in the sample have a characteristic intrinsic brightness temperature,
$T_{\rm 0} = 4.8^{+2.6}_{-1.5}\times 10^{9}$ K, which is lower than the
equipartition temperature for the condition that the particle energy equals to
the magnetic field energy. Our results suggest that the VLBI cores seen at 86
GHz may be representing a jet region where the magnetic field energy dominates
the total energy in the jet.


title: Ideal Class Group Algorithms in the Ring of Integral Quaternions

abstract:
  An ideal is a classical object of study in the field of algebraic number
theory. In maximal quadratic orders of number fields, ideals usually
represented by the $\mathbb Z$-basis. This form of representation is used in
most of the algorithms for ideal manipulation. However, this is not the only
option, as an ideal can also be represented by its generating set. Moreover, in
certain quadratic orders of the ring of integral quaternions, every ideal can
be represented by a single quaternion, called a pseudo generator.
  In this paper, we develop algorithms which allow us to manipulate ideals
using solely their pseudo generators. We also demonstrate the connection
between the three squares problem and factorization. This result comes as an
extension of a number factoring technique discovered by Fermat, which allows
the factoring of an integer if a pair of its two squares representations is
known. In addition to this, we present a number of identities, which ideals
must satisfy; some computational data on the number of ambiguous classes,
generated by the equation $\rho\mu = -\mu\rho$; and a new approach to the
problem of finding a non-trivial divisor of a class number.


title: The scalar Green function of the Kerr spacetime

abstract:
  In this paper we study the scalar Green function in the Kerr spacetime using
WKB methods. The Green function can be expressed by Fourier-transforming to its
frequency-domain counterpart, and with the help of complex analysis it can be
divided into parts: 1) the "direct part" which propagates on the light cone and
dominates at very early times; 2) the "quasinormal-mode part" which represents
the waves traveling around the photon sphere, and is important at early and
intermediate times; 3) the "tail part" which is due to scattering by the
Coulomb-type potential and becomes more important at later times. We focus on
the "quasinormal-mode part" of the Green function and derive an approximate
analytical formula for it using WKB techniques. This approximate Green function
diverges at points that are connected by null geodesics, and recovers the
four-fold singular structure of Green functions that are seen in Schwarzschild
and other spacetimes. It also carries unique signatures of the Kerr spacetime
such as frame-dragging. Along the way, we also derive approximate quasinormal
mode wavefunctions and expressions for the black hole excitation factors in the
Kerr spacetime. We expect this work to benefit the understanding of both wave
propagation and the problem of self-force in the Kerr spacetime.


title:
Bifurcation of ten small-amplitude limit cycles by perturbing a
  quadratic Hamiltonian system

abstract:
  This paper contains two parts. In the first part, we shall study the Abelian
integrals for Zoladek's example [13], in which it is claimed the existence
integrals of 11 small-amplitude limit cycles around a singular point in a
particular cubic vector filed. We will show that the basis chosen in the proof
of [13] are not independent, which leads to failure in drawing the conclusion
of the existence of 11 limit cycles in this example. In the second part, we
present a good combination of Melnikov function method and focus value (or
normal form) computation method to study bifurcation of limit cycles. An
example by perturbing a quadratic Hamiltonian system with cubic polynomials is
presented to demonstrate the advantages of both methods, and 10 small-amplitude
limit cycles bifurcating from a center are obtained by using up to 5th-order
Melnikov functions.


title:
Unit cell determination of epitaxial thin films based on reciprocal
  space vectors by high-resolution X-ray diffractometry

abstract:
  A new approach, based on reciprocal space vectors (RSVs), is developed to
determine Bravais lattice types and accurate lattice parameters of epitaxial
thin films by high-resolution X-ray diffractometry (HR-XRD). The lattice
parameters of single crystal substrates are employed as references to correct
the systematic experimental errors of RSVs of thin films. The general procedure
is summarized, involving correction of RSVs, derivation of raw unit cell,
subsequent conversion to the Niggli unit cell and the Bravais unit cell by
matrix calculation.Two methods of this procedure are described in 3D reciprocal
space and 6D G6-space, respectively. The estimation of standard error in the
lattice parameters derived by this new approach is discussed. The whole
approach is illustrated by examples of experimental data. The error of the best
result is 0.0006 {\AA} for the lattice parameter of ITO (Indium tin oxide)
film. This new RSV method provides a practical and concise route to crystal
structure study of epitaxial thin films, which could also be applied to the
investigation of surface and interface structures.


title: Seifert surfaces in open books, and pass moves on links

abstract:
  The flat plumbing basket presentation of a link is introduced by Furihata,
Hirasawa and Kobayashi. In this paper, we show that the pass-equivalence and an
equivalence introduced by using the flat plumbing basket presentation are the
same relation. Furthermore, we obtain an evaluation of the minimal number of
bands used for the flat pluming basket presentation for a knot coming from the
degree of the Alexander polynomial and the three genus of the knot.


title: Generalized Kerr/CFT correspondence with electromagnetic field

abstract:
  The electrovac axisymmetric extreme isolated horizon/CFT correspondence is
considered. By expansion techniques under the Bondi-like coordinates, it is
proved that the near horizon geometry of electrovac axisymmetric extreme
isolated horizon is unique. Furthermore, explicit coordinate transformation
between the Bondi-like coordinates and the Poincare-type coordinates for the
near horizon metric of the extreme Kerr-Newmann spacetime is found. Based on
these analyses and the thermodynamics of the isolated horizon, then, the
Kerr/CFT correspondence is generalized to nonstationary extreme black holes
with electromagnetic fields.


title: Automotion of Domain Walls for Spintronic Interconnects

abstract:
  We simulate automotion, the spontaneous transport of a magnetic domain wall
under the influence of demagnetization and magnetic anisotropy, in nanoscale
spintronic interconnects. In contrast to spin transfer driven magnetic domain
wall motion, the proposed interconnects operate with only a transient current
pulse and provide favorable scaling down to the 20nm scale. Cases of both
in-plane and perpendicular magnetization are considered. Analytical dependence
of the velocity of domain walls on the angle of magnetization are compared with
full micromagnetic simulations. Deceleration, disappearance, and reflection of
domain walls are demonstrated. Dependences of the magnetization angle on the
current pulse parameters are studied. The energy and delay analysis suggests
that automotion is an attractive option for spintronic logic interconnects.


title:
Poisson structures for two nonholonomic systems with partially reduced
  symmetries

abstract:
  We consider nonholonomic systems which symmetry groups consist of two
subgroups one of which represents rotations about the axis of symmetry. After
nonholonomic reduction by another subgroup the corresponding vector fields on
partially reduced phase space are linear combinations of the Hamiltonian and
symmetry vector fields. The reduction of the Poisson bivectors associated with
the Hamiltonian vector fields to canonical form is discussed.


title:
Performance of General STCs over Spatially Correlated MIMO
  Single-keyhole Channels

abstract:
  For MIMO Rayleigh channels, it has been shown that transmitter correlations
always degrade the performance of general space-time codes (STCs) in high SNR
regimes. In this correspondence, however, we show that when MIMO channels
experience single-keyhole conditions, the effect of spatial correlations
between transmission antennas is more sophisticated for general STCs: when
$M>N$ (i.e., the number of transmission antennas is greater than the number of
receiving antennas), depending on how the correlation matrix $\mathbf{P}$
beamforms the code word difference matrix $\mathbf{\Delta}$, the PEP
performance of general STCs can be either degraded or improved in high SNR
regimes. We provide a new measure, which is based on the eigenvalues of
$\mathbf{\Delta}$ and the numbers of transmission and receiving antennas, to
exam if there exists certain correlation matrices that can improve the
performance of general STCs in high SNR regimes. Previous studies on the effect
of spatial correlations over single-keyhole channels only concentrated on
orthogonal STCs, while our study here is for general STCs and can also be used
to explain previous findings for orthogonal STCs.


title:
Valley Carrier Dynamics in Monolayer Molybdenum Disulphide from Helicity
  Resolved Ultrafast Pump-probe Spectroscopy

abstract:
  We investigate the valley related carrier dynamics in monolayer MoS2 using
helicity resolved non-degenerate ultrafast pump-probe spectroscopy at the
vicinity of the high-symmetry K point under the temperature down to 78 K.
Monolayer MoS2 shows remarkable transient reflection signals, in stark contrast
to bilayer and bulk MoS2 due to the enhancement of many-body effect at reduced
dimensionality. The helicity resolved ultrafast time-resolved result shows that
the valley polarization is preserved for only several ps before scattering
process makes it undistinguishable. We suggest that the dynamical degradation
of valley polarization is attributable primarily to the exciton trapping by
defect states in the exfoliated MoS2 samples. Our experiment and a
tight-binding model analysis also show that the perfect valley CD selectivity
is fairly robust against disorder at the K point, but quickly decays from the
high-symmetry point in the momentum space in the presence of disorder.


title: Hadronic gamma-Z box corrections in M\oller scattering

abstract:
  The possibility of measuring the parity-violating asymmetry in M\oller
scattering with sufficient accuracy to determine sin^2 theta_W to 0.1% offers a
complementary path to the discovery of new physics to that followed at high
energy colliders. We present a new calculation of the gamma-Z box contribution
to parity-violating electron-proton scattering, which constitutes an important
uncertainty in computing the background to this process. We show that while the
gamma-Z correction grows rapidly with energy, it can be relatively well
constrained by data from parity-violating inelastic scattering and parton
distribution functions.


title: Rapidity Profile of the Initial Energy Density in Heavy-Ion Collisions

abstract:
  The rapidity dependence of the initial energy density in heavy-ion collisions
is calculated from a three-dimensional McLerran-Venugopalan model (3dMVn)
introduced by Lam and Mahlon. This model is infrared safe since global color
neutrality is enforced. In this non-boost-invariant framework, the nuclei have
non-zero thickness in the longitudinal direction. This results in Bjorken-x
dependent unintegrated gluon distribution functions which lead to a
rapidity-dependent initial energy density after the collision. The initial
energy density and its rapidity dependence are important initial conditions for
the quark gluon plasma and its hydrodynamic evolution.


title: A Class of Six-weight Cyclic Codes and Their Weight Distribution

abstract:
  In this paper, a family of six-weight cyclic codes over GF(p) whose duals
have two zeros is presented, where p is an odd prime. And the weight
distribution of these cyclic codes is determined.


title:
Giant dipole resonance width and the universality of the Critical
  Temperature included Fluctuation Model

abstract:
  The universality of the Critical Temperature included Fluctuation Model
(CTFM) in explaining the evolution of the giant dipole resonance (GDR) width as
a function of angular momentum is examined in the light of recent experimental
data on $^{144}$Sm and $^{152}$Gd. We compare both the data sets with the
phenomenological formula based on the CTFM and the thermal shape fluctuation
model (pTSFM). The CTFM describes both the data sets reasonably well using the
actual ground state GDR width ($\Gamma_0$) values, whereas, the pTSFM describes
the $^{144}$Sm data well but is unable to explain the $^{152}$Gd data using a
single value of $\Gamma_0$ for two excitation energies. These interesting
results clearly indicate that the phenomenological CTFM can be used universally
to describe the evolution of the GDR width with both angular momentum and
temperature in the entire mass region. Moreover, it should provide new insights
into the modification of the TSFM.


title: S-Duality for D3-Brane in NS-NS and R-R Backgrounds

abstract:
  We construct the low-energy effective field theory for a D3-brane in constant
R-R 2-form potential background as the S-dual theory of a D3-brane in NS-NS
B-field background. Despite the non-Abelian algebra of the noncommutative U(1)
gauge symmetry, the electromagnetic duality transformation can be carried out
to all orders, and the dual Lagrangian is given in a compact form. The gauge
algebra is found to be a mixture of a deformed area-preserving diffeomorphism
and the usual U(1) gauge symmetry.


title: Integrated Expert Recommendation Model for Online Communities

abstract:
  Online communities have become vital places for Web 2.0 users to share
knowledge and experiences. Recently, finding expertise user in community has
become an important research issue. This paper proposes a novel cascaded model
for expert recommendation using aggregated knowledge extracted from enormous
contents and social network features. Vector space model is used to compute the
relevance of published content with respect to a specific query while PageRank
algorithm is applied to rank candidate experts. The experimental results show
that the proposed model is an effective recommendation which can guarantee that
the most candidate experts are both highly relevant to the specific queries and
highly influential in corresponding areas.


title:
Low-Temperature Pseudogap Phenomenon: Precursor of High-$T_c$
  Superconductivity

abstract:
  In this paper, we try to understand the pseudogap phenomenon observed in the
cuprate superconductor through a model study. Specifically, we explore the
so-called low-temperature pseudogap state by turning off the superconducting
off diagonal long range order in an ansatz state for the $t$-$J$ model [New
Journal of Physics {\bf 13}, 103039 (2011)]. Besides strong non-Gaussian
superconducting fluctuations, the resulting state also exhibits a systematic
pseudogap behavior in both spin and charge degrees of freedom, manifested in
the uniform spin susceptibility, specific heat, non-Drude resistivity, Nernst
effect, as well as the quantum oscillation associated with small Fermi pockets
emerging in strong magnetic fields, etc. These anomalous `normal state'
properties are found in qualitative consistency with experimental measurements
in the cuprates. Such a model study establishes an intrinsic connection between
the peculiar pseudogap properties and the non-BCS nature of the superconducting
ground state. Critical comparison with other approaches to the doped Mott
insulator is also made.


title: When Equivalence and Bisimulation Join Forces in Probabilistic Automata

abstract:
  Probabilistic automata were introduced by Rabin in 1963 as language
acceptors. Two automata are equivalent if and only if they accept each word
with the same probability. On the other side, in the process algebra community,
probabilistic automata were re-proposed by Segala in 1995 which are more
general than Rabin's automata. Bisimulations have been proposed for Segala's
automata to characterize the equivalence between them. So far the two notions
of equivalences and their characteristics have been studied most independently.
In this paper, we consider Segala's automata, and propose a novel notion of
distribution based bisimulation by joining the existing equivalence and
bisimilarities. Our bisimulation bridges the two closely related concepts in
the community, and provides a uniform way of studying their characteristics. We
demonstrate the utility of our definition by studying distribution based
bisimulation metrics, which gives rise to a robust notion of equivalence for
Rabin's automata.


title: The International Linear Collider

abstract:
  In this article, we describe the key features of the recently completed
technical design for the International Linear Collider (ILC), a 200-500 GeV
linear electron-positron collider (expandable to 1 TeV) that is based on 1.3
GHz superconducting radio-frequency (SCRF) technology. The machine parameters
and detector characteristics have been chosen to complement the Large Hadron
Collider physics, including the discovery of the Higgs boson, and to further
exploit this new particle physics energy frontier with a precision instrument.
The linear collider design is the result of nearly twenty years of R&D,
resulting in a mature conceptual design for the ILC project that reflects an
international consensus. We summarize the physics goals and capability of the
ILC, the enabling R&D and resulting accelerator design, as well as the concepts
for two complementary detectors. The ILC is technically ready to be proposed
and built as a next generation lepton collider, perhaps to be built in stages
beginning as a Higgs factory.


title:
Critical properties of a dissipative sandpile model on small world
  networks

abstract:
  A dissipative sandpile model (DSM) is constructed and studied on small world
networks (SWN). SWNs are generated adding extra links between two arbitrary
sites of a two dimensional square lattice with different shortcut densities
$\phi$. Three different regimes are identified as regular lattice (RL) for
$\phi\lesssim 2^{-12}$, SWN for $2^{-12}<\phi< 0.1$ and random network (RN) for
$\phi\ge 0.1$. In the RL regime, the sandpile dynamics is characterized by
usual Bak, Tang, Weisenfeld (BTW) type correlated scaling whereas in the RN
regime it is characterized by the mean field (MF) scaling. On SWN, both the
scaling behaviors are found to coexist. Small compact avalanches below certain
characteristic size $s_c$ are found to belong to the BTW universality class
whereas large, sparse avalanches above $s_c$ are found to belong to the MF
universality class. A scaling theory for the coexistence of two scaling forms
on SWN is developed and numerically verified. Though finite size scaling (FSS)
is not valid for DSM on RL as well as on SWN, it is found to be valid on RN for
the same model. FSS on RN is appeared to be an outcome of super diffusive sand
transport and uncorrelated toppling waves.


title:
Jackson's inequality in the complex plane and the Lojasiewicz-Siciak
  inequality of Green's function

abstract:
  We prove a generalization of Dunham Jackson's famous approximation inequality
to the case of compact sets in the complex plane admitting both upper and lower
bounds for their Green's functions, i.e. the well known Holder Continuity
Property (HCP) and the less known but crucial Lojasiewicz-Siciak inequality
(LS). Moreover, we show that (LS) is a necessary condition for our Jackson type
inequality.


title: New look at the QCD ground state in a magnetic field

abstract:
  We explore chiral symmetry breaking in a magnetic field within a
Nambu-Jona-Lasinio model of interacting massless quarks including tensor
channels. We show that the new interaction channels open up via Fierz
identities due to the explicit breaking of the rotational symmetry by the
magnetic field. We demonstrate that the magnetic catalysis of chiral symmetry
breaking leads to the generation of two independent condensates, the
conventional chiral condensate and a spin-one condensate. While the chiral
condensate generates a dynamical fermion mass, the new condensate gives rise to
a dynamical anomalous magnetic moment for the fermions. As a consequence, the
spectrum of the excitations in all Landau levels, except the lowest one,
exhibits Zeeman splitting. Since the pair, formed by a quark and an antiquark
with opposite spins, possesses a resultant magnetic moment, an external
magnetic field can align it giving rise to a net magnetic moment for the ground
state. This is the physical interpretation of the spin-one condensate. Our
results show that the magnetically catalyzed ground state in QCD is actually
richer than previously thought. The two condensates contribute to the effective
mass of the LLL quasiparticles in such a way that the critical temperature for
chiral symmetry restoration becomes enhanced.


title: Recent Results in Polarized Proton-Proton Elastic Scattering at STAR

abstract:
  RHIC is the only spin-polarized proton collider ever built. With a special
optics run of $\beta^\star \approx 22$ m STAR detector system is suitable for
an investigation of the spin dependence of elastic proton-proton scattering.
This is a brief summary of measurements of spin asymmetries at the center of
mass energy $\sqrt{s}=200$ GeV and in the four-momentum transfer squared $-t$
range $0.003 < -t < 0.035$ GeV$^2$ by the STAR experiment at RHIC.


title: Colossal Thermoelectric Power Factor in K$_{7/8}$RhO$_2$

abstract:
  We discuss the thermoelectric and optical properties of layered
K$_{x}$RhO$_{2}$ (\emph{x} = 1/2 and 7/8) in terms of the electronic structure
determined by first principles calculations as well as Boltzmann transport
theory. Our optimized lattice constants differ significantly from the
experiment, but result in optical and transport properties close to the
experiment. The main contribution to the optical spectra are due to intra and
inter-band transitions between the Rh 4\emph{d} and O 2\emph{p} states. We find
a similar power factor for pristine K$_{x}$RhO$_{2}$ at low and high cation
concentartions. Our transport results of hydrated K$_{x}$RhO$_{2}$ at room
temperature show highest value of the power factor among the hole-type
materials. Specially at 100 K, we obtain a value of 3$\times$10$^{-3}$ K$^{-1}$
for K$_{7/8}$RhO$_{2}$, which is larger than that of Na$_{0.88}$CoO$_{2}$ {[}M.
Lee \emph{et al}., Nat. Mater. 5, 537 (2006){]}. In general, the electronic and
optical properties of K$_{x}$RhO$_{2}$ are similar to Na$_{x}$CoO$_{2}$ with
enhanced transport properties in the hydrated phase.


title: Study of 3He inelastic scattering on 13C and 14C at 37.9 MeV

abstract:
  The differential cross sections of elastic and inelastic scattering of 3He
ions on 13C and 14C have been studied at energy of 37.9 MeV with a double
folding model based on M3Y-Reid effective nucleon-nucleon interaction. The
resulted parameters have been used for the standard Distorted Wave Born
Approximation calculations of angular distributions corresponding to different
excitations levels of 13C and 14C and deformation parameters have been deduced.


title:
Flavor dependence of the spin-independent and spin-dependent parts of
  $GDPs(x,t, \xi=0)$

abstract:
  The different sets of PDF with the new form of t-dependence of generalized
parton distributions (GPDs) were examined in the descriptions of the
electromagnetic form factors of the proton and neutron. One of the purposes was
to minimize the number of fitting parameters. We found that main flavor
difference related to the spin-dependent of PDF incoming as part in GPDs.
Hence, contrary to some other work, our result shows a little flavor dependence
of the t-dependence of the $GPDs(x,t,\xi=0$).


title:
The STONE Transform: Multi-Resolution Image Enhancement and Real-Time
  Compressive Video

abstract:
  Compressed sensing enables the reconstruction of high-resolution signals from
under-sampled data. While compressive methods simplify data acquisition, they
require the solution of difficult recovery problems to make use of the
resulting measurements. This article presents a new sensing framework that
combines the advantages of both conventional and compressive sensing. Using the
proposed \stone transform, measurements can be reconstructed instantly at
Nyquist rates at any power-of-two resolution. The same data can then be
"enhanced" to higher resolutions using compressive methods that leverage
sparsity to "beat" the Nyquist limit. The availability of a fast direct
reconstruction enables compressive measurements to be processed on small
embedded devices. We demonstrate this by constructing a real-time compressive
video camera.


title: Full characterization of optimal transport plans for concave costs

abstract:
  This paper slightly improves a classical result by Gangbo and McCann (1996)
about the structure of optimal transport plans for costs that are concave
functions of the Euclidean distance. Since the main difficulty for proving the
existence of an optimal map comes from the possible singularity of the cost at
$0$, everything is quite easy if the supports of the two measures are disjoint;
Gangbo and McCann proved the result under the assumption $\mu(\spt(\nu))=0$; in
this paper we replace this assumption with the fact that the two measures are
singular to each other. In this case it is possible to prove the existence of
an optimal transport map, provided the starting measure $\mu$ does not give
mass to small sets (i.e. $(d\!-\!1)-$rectifiable sets). When the measures are
not singular the optimal transport plan decomposes into two parts, one
concentrated on the diagonal and the other being a transport map between
mutually singular measures.


title:
Half-metallicity and giant magneto-optical Kerr effect in N-doped
  NaTaO$_3$

abstract:
  We employ density functional theory using the modified Becke-Johnson (mBJ)
approach to investigate the electronic and magneto-optical properties of
N-doped NaTaO$_3$. The mBJ results reveal a half metallic nature of NaTaO$_2$N,
in contrast to results obtained by the generalized gradient approximation. We
find a giant polar Kerr rotation of 2.16$^{\circ}$ at 725 nm wave length
(visible region), which is high as compared to other half metallic perovskites
as well as to the prototypical half metal PtMnSb.


title: The phenomenon of state reduction

abstract:
  A theory of quantum measurement was introduced some time ago that was based
on the notion of the so-called separation status. This separation status had a
spatial, local character, so that the theory worked only in special cases.
Nevertheless, it enabled a description of state reduction process that was
specific in where, when and under which objective conditions the process occurs
and that preserved the unitary transformation symmetry of quantum mechanics.
Now, in an accompanying paper (arxiv:1411.5524), a completely general
mathematical definition of the status is given and analyzed. The present paper
reformulates the theory of state reduction accordingly. A general mathematical
form of the process is postulated and illustrated by examples of Stern-Gerlach
experiment and of screening.


title:
Extremal behavior of squared Bessel processes attracted by the
  Brown-Resnick process

abstract:
  The convergence of properly time-scaled and normalized maxima of independent
standard Brownian motions to the Brown-Resnick process is well-known in the
literature. In this paper, we study the extremal functional behavior of
non-Gaussian processes, namely squared Bessel processes and scalar products of
Brownian motions. It is shown that maxima of independent samples of those
processes converge weakly on the space of continuous functions to the
Brown-Resnick process.


title:
Impact of lattice strain on the tunnel magneto-resistance in
  Fe/Insulator/Fe and Fe/Insulator/La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ magnetic
  tunnel junctions

abstract:
  The objective of this work is to describe the tunnel electron current in
single barrier magnetic tunnel junctions within a new approach that goes beyond
the single-band transport model. We propose a ballistic multi-channel electron
transport model that can explain the influence of in-plane lattice strain on
the tunnel magnetoresistance as well as the asymmetric voltage behavior. We
consider as an example single crystal magnetic Fe(110) electrodes for
Fe/Insulator/Fe and Fe/Insulator/La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ tunnel
junctions, where the electronic band structures of Fe and
La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ are derived by \it{ab-initio} calculations.


title:
Measurements of strong phase in $D^0\to K\pi$ decay and $y_\mathrm{CP}$
  at BESIII

abstract:
  In this paper, I report the preliminary results of the strong phase
difference $\cos\delta_{K\pi}$ between the doubly Cabibbo-suppressed process
$\overline{D}{}^0\to K^- \pi^+$ and Cabibbo-favored $D^0\to K^- \pi^+$ at
BESIII. In addition, the preliminary results of the $D^0$-$\overline{D}{}^0$
mixing parameter $y_\mathrm{CP}$ by analyzing $CP$-tagged semileptonic $D$
decays are presented. These measurements were carried out based on the
quantum-correlated technique in studying the process of $D^0\overline{D}{}^0$
pair productions of 2.92 fb$^{-1}$ $e^+e^-$ collision data collected with the
BESIII detector at $\sqrt{s}$ = 3.773 GeV.


title: Toward a numerical deshaker for PFS

abstract:
  The Planetary Fourier Spectrometer (PFS) onboard Mars Express (MEx) is the
instrument with the highest spectral resolution observing Mars from orbit since
January 2004. It permits studying the atmospheric structure, major and minor
compounds. The present time version of the calibration is limited by the
effects of mechanical vibration, currently not corrected. We proposed here a
new approach to correct for the vibrations based on semi-blind deconvolution of
the measurements. This new approach shows that a correction can be done
efficiently with 85% reduction of the artefacts, in a equivalent manner to the
stacking of 10 spectra. Our strategy is not fully automatic due to the
dependence on some regularisation parameters. It may be applied on the complete
PFS dataset, correcting the large-scale perturbation due to microvibrations for
each spectrum independently. This approach is validated on actual PFS data of
Short Wavelength Channel (SWC), perturbed by microvibrations. A coherence check
can be performed and also validate our approach. Unfortunately, the coherence
check can be done only on the first 310 orbits of MEx only, until the laser
line has been switch off. More generally, this work may apply to numerically
"deshake" Fourier Transform Spectrometer (FTS), widely used in space
experiments or in the laboratory.


title:
Force-free field modeling of twist and braiding-induced magnetic energy
  in an active-region corona

abstract:
  The theoretical concept that braided magnetic field lines in the solar corona
may dissipate a sufficient amount of energy to account for the brightening
observed in the active-region corona, has been substantiated by high-resolution
observations only recently. From the analysis of coronal images obtained with
the High Resolution Coronal Imager, first observational evidence of the
braiding of magnetic field lines was reported by Cirtain et al. 2013 (hereafter
CG13). We present nonlinear force-free reconstructions of the associated
coronal magnetic field based on vector SDO/HMI magnetograms. We deliver
estimates of the free magnetic energy associated to a braided coronal
structure. Our model results suggest (~100 times) more free energy at the
braiding site than analytically estimated by CG13, strengthening the
possibility of the active-region corona being heated by field line braiding. We
were able to assess the coronal free energy appropriately by using vector field
measurements and attribute the lower energy estimate of CG13 to the
underestimated (by a factor of 10) azimuthal field strength. We also quantify
the increase of the overall twist of a flare-related flux rope which had been
claimed by CG13. From our models we find that the overall twist of the flux
rope increased by about half a turn within twelve minutes. Unlike another
method, to which we compare our results to, we evaluate the winding of the flux
rope's constituent field lines around each other purely based on their modeled
coronal 3D field line geometry -- to our knowledge for the first time.


title:
Mining Software Repair Models for Reasoning on the Search Space of
  Automated Program Fixing

abstract:
  This paper is about understanding the nature of bug fixing by analyzing
thousands of bug fix transactions of software repositories. It then places this
learned knowledge in the context of automated program repair. We give extensive
empirical results on the nature of human bug fixes at a large scale and a fine
granularity with abstract syntax tree differencing. We set up mathematical
reasoning on the search space of automated repair and the time to navigate
through it. By applying our method on 14 repositories of Java software and
89,993 versioning transactions, we show that not all probabilistic repair
models are equivalent.


title:
Influence of substitution on the optical properties of functionalized
  pentacene monomers and crystals: Experiment and theory

abstract:
  The influence of solubilizing substitutional groups on the electronic and
optical properties of functionalized pentacene molecules and crystals have been
investigated. Density functional theory is used to calculate the electronic and
optical properties of pentacene, TIBS-CF$_{3}$-pentacene, and TIPS-pentacene.
The results are compared with experimental absorption spectra of solutions and
the complex dielectric function of thin films in the 1 eV to 3 eV energy range.
In all cases, the band gaps of the isolated molecules are found to be smaller
than those of the crystals. The absorption spectra and dielectric function are
interpreted in terms of the transitions between the highest occupied molecular
orbitals and lowest unoccupied molecular orbitals. The bands associated to C
and Si atoms connecting the functional side group to the pentacene in the
(6,13) positions are found to be the main contributors to the optical
transitions. The calculated dielectric functions of thin films agree with the
experimental results. A redshift is observed in crystals as compared to
molecules in experiment and theory both, where the amplitude depends on the
packing structure.


title: Quantum synchronizable codes from finite geometries

abstract:
  Quantum synchronizable error-correcting codes are special quantum
error-correcting codes that are designed to correct both the effect of quantum
noise on qubits and misalignment in block synchronization. It is known that in
principle such a code can be constructed through a combination of a classical
linear code and its subcode if the two are both cyclic and dual-containing.
However, finding such classical codes that lead to promising quantum
synchronizable error-correcting codes is not a trivial task. In fact, although
there are two families of classical codes that are proved to produce quantum
synchronizable codes with good minimum distances and highest possible tolerance
against misalignment, their code lengths have been restricted to primes and
Mersenne numbers. In this paper, examining the incidence vectors of projective
spaces over the finite fields of characteristic $2$, we give quantum
synchronizable codes from cyclic codes whose lengths are not primes or Mersenne
numbers. These projective geometric codes achieve good performance in quantum
error correction and possess the best possible ability to recover
synchronization, thereby enriching the variety of good quantum synchronizable
codes. We also extend the current knowledge of cyclic codes in classical coding
theory by explicitly giving generator polynomials of the finite geometric codes
and completely characterizing the minimum weight nonzero codewords. In addition
to the codes based on projective spaces, we carry out a similar analysis on the
well-known cyclic codes from Euclidean spaces that are known to be majority
logic decodable and determine their exact minimum distances.


title:
Order and chaos in a new 3D dynamical model describing motion in non
  axially symmetric galaxies

abstract:
  We present a new dynamical model describing 3D motion in non axially
symmetric galaxies. The model covers a wide range of galaxies from a disk
system to an elliptical galaxy by suitably choosing the dynamical parameters.
We study the regular and chaotic character of orbits in the model and try to
connect the degree of chaos with the parameter describing the deviation of the
system from axial symmetry. In order to obtain this, we use the Smaller
ALingment Index (SALI) technique by numerically integrating the basic equations
of motion, as well as the variational equations for extensive samples of
orbits. Our results suggest, that the influence of the deviation parameter on
the portion of chaotic orbits strongly depends on the vertical distance $z$
from the galactic plane of the orbits. Using different sets of initial
conditions, we show that the chaotic motion is dominant in galaxy models with
low values of $z$, while in the case of stars with large values of $z$ the
regular motion is more abundant, both in elliptical and disk galaxy models.


title: Particle-like Q-balls

abstract:
  Usually the charge and the energy of stable Q-balls vary in a wide range or
are even unbounded. In the present paper we study an interesting possibility
that this range is parametrically small. In this case the spectra of stable
Q-balls look similar to the one of free particles.


title:
Constraints on the dark matter equation of state with redshift-space
  distortion

abstract:
  In this paper, we study a model which is composed by the cosmological
constant and dark matter with nonzero equation of state parameter, which could
be called as $\Lambda$wDM. In the synchronous gauge, we obtain the perturbation
equations of dark matter, and deduce the evolution equations of growth factor
about the dark matter and baryons. Based on the Markov Chain Monte Carlo
method, we constrain this model by the recently available cosmic observations
which include cosmic microwave background radiation, baryon acoustic
oscillation, type Ia supernovae, and $f\sigma_8(z)$ data points from
redshift-space distortion. The results present a tighter constraint on the
model than the case without $f\sigma_8(z)$ data. In 3$\sigma$ regions, we find
the dark matter equation of state parameter $w_{dm}$=$0.000111_{-
0.000701-0.00137-0.00180}^{+0.000688+0.00136+0.00181}$. After an extra model
parameter $w_{dm}$ is considered, the difference between the minimum values of
$\chi^2$ of our model and standard model is $\Delta\chi^2_{min}=0.598$.
Although the currently available cosmic observations mildly favor the nonzero
dark matter equation of state parameter, no significant deviation from the
$\Lambda$CDM model is found in 1$\sigma$ region.


title: Testing V3Si for two-band superconductivity

abstract:
  Is V3Si a two-band or a single-band superconductor? Everyone who searches the
literature for this question will find conflicting answers, for V3Si was
claimed to be a perfect example of two-band and claimed to be a perfect example
of single-band superconductivity. In this article we intend to clarify the
situation by presenting new experimental facts acquired from the magnetic
properties of a V3Si single crystal. We probe for field dependent two-band
effects by analyzing the reversible magnetization at different temperatures,
and we probe for temperature dependent two-band effects by analyzing the
superfluid density obtained by two different methods at different magnetic
fields. All our results are reliably described within the single-band models
and thus support the single-band scenario for V3Si but do not completely rule
out the presence of a very small second gap.


title: Apparent ghosts and spurious degrees of freedom in non-local theories

abstract:
  Recent work has shown that non-local modifications of the Einstein equations
can have interesting cosmological consequences and can provide a dynamical
origin for dark energy, consistent with existing data. At first sight these
theories are plagued by ghosts. We show that these apparent ghost-like
instabilities do not describe actual propagating degrees of freedom, and there
is no issue of ghost-induced quantum vacuum decay.


title: Measurement of Neutrino Masses from Relative Velocities

abstract:
  We present a new technique to measure neutrino masses using their flow field
relative to dark matter. Present day streaming motions of neutrinos relative to
dark matter and baryons are several hundred km/s, comparable with their thermal
velocity dispersion. This results in a unique dipole anisotropic distortion of
the matter-neutrino cross power spectrum, which is observable through the
dipole distortion in the cross correlation of different galaxy populations.
Such a dipole vanishes if not for this relative velocity and so it is a clean
signature for neutrino mass. We estimate the size of this effect and find that
current and future galaxy surveys may be sensitive to these signature
distortions.


title: Strong dynamical effects during stick-slip adhesive peeling

abstract:
  We consider the classical problem of the stick-slip dynamics observed when
peeling a roller adhesive tape at a constant velocity. From fast imaging
recordings, we extract the dependencies of the stick and slip phases durations
with the imposed peeling velocity and peeled ribbon length. Predictions of
Maugis and Barquins [in Adhesion 12, edited by K.W. Allen, Elsevier ASP,
London, 1988, pp. 205--222] based on a quasistatic assumption succeed to
describe quantitatively our measurements of the stick phase duration. Such
model however fails to predict the full stick-slip cycle duration, revealing
strong dynamical effects during the slip phase.


title:
MOA-2008-BLG-379Lb: A Massive Planet from a High Magnification Event
  with a Faint Source

abstract:
  We report analysis of high microlensing event MOA-2008-BLG-379, which has a
strong microlensing anomaly at its peak, due to a massive planet with a mass
ratio of q = 6.9 x 10^{-3}. Because the faint source star crosses the large
resonant caustic, the planetary signal dominates the light curve. This is
unusual for planetary microlensing events, and as a result, the planetary
nature of this light curve was not immediately noticed. The planetary nature of
the event was found when the MOA Collaboration conducted a systematic study of
binary microlensing events previously identified by the MOA alert system. We
have conducted a Bayesian analysis based on a standard Galactic model to
estimate the physical parameters of the lens system. This yields a host star
mass of M_L = 0.66_{-0.33}^{+0.29} M_Sun orbited by a planet of mass m_P =
4.8_{-2.4}^{+2.1} M_Jup at an orbital separation of a = 4.1_{-1.5}^{+1.9} AU at
a distance of D_L = 3.6 +/- 1.3 kpc. The faint source magnitude of I_S = 21.30
and relatively high lens-source relative proper motion of mu_rel = 7.6 +/- 1.6
mas/yr implies that high angular resolution adaptive optics or Hubble Space
Telescope observations are likely to be able to detect the source star, which
would determine the masses and distance of the planet and its host star.


title:
Breathe before Speaking: Efficient Information Dissemination Despite
  Noisy, Limited and Anonymous Communication

abstract:
  Distributed computing models typically assume reliable communication between
processors. While such assumptions often hold for engineered networks, e.g.,
due to underlying error correction protocols, their relevance to biological
systems, wherein messages are often distorted before reaching their
destination, is quite limited. In this study we take a first step towards
reducing this gap by rigorously analyzing a model of communication in large
anonymous populations composed of simple agents which interact through short
and highly unreliable messages.
  We focus on the broadcast problem and the majority-consensus problem. Both
are fundamental information dissemination problems in distributed computing, in
which the goal of agents is to converge to some prescribed desired opinion. We
initiate the study of these problems in the presence of communication noise.
Our model for communication is extremely weak and follows the push gossip
communication paradigm: In each round each agent that wishes to send
information delivers a message to a random anonymous agent. This communication
is further restricted to contain only one bit (essentially representing an
opinion). Lastly, the system is assumed to be so noisy that the bit in each
message sent is flipped independently with probability $1/2-\epsilon$, for some
small $\epsilon >0$.
  Even in this severely restricted, stochastic and noisy setting we give
natural protocols that solve the noisy broadcast and the noisy
majority-consensus problems efficiently. Our protocols run in $O(\log n /
\epsilon^2)$ rounds and use $O(n \log n / \epsilon^2)$ messages/bits in total,
where $n$ is the number of agents. These bounds are asymptotically optimal and,
in fact, are as fast and message efficient as if each agent would have been
simultaneously informed directly by an agent that knows the prescribed desired
opinion.


title: Review of Recent Results from the RHIC Beam Energy Scan

abstract:
  We review recent results from the RHIC beam energy scan (BES) program, aimed
to study the Quantum Chromodynamics (QCD) phase diagram. The main goals are to
search for the possible phase boundary, softening of equation of state or first
order phase transition, and possible critical point. Phase-I of the BES program
has recently concluded with data collection for Au+Au collisions at
center-of-mass energies ($\sqrt{s_{NN}}$) of 7.7, 11.5, 19.6, 27, and 39 GeV.
Several interesting results are observed for these lower energies where the
net-baryon density is high at the mid-rapidity. These results indicate that the
matter formed at lower energies (7.7 and 11.5 GeV) is hadron dominated and
might not have undergone a phase transition. In addition, the centrality
dependence of freeze-out parameters is observed for the first time at lower
energies, slope of directed flow for (net)-protons measured versus rapidity
shows an interesting behavior at lower energies, and higher moments of
net-proton show deviation from Skellam expectations at lower energies. An
outlook for the future BES Phase-II program is presented and efforts for the
detailed study of QCD phase diagram are discussed.


title: PsrPopPy: An open-source package for pulsar population simulations

abstract:
  We have produced a new software package for the simulation of pulsar
populations, \textsc{PsrPopPy}, based on the \textsc{Psrpop} package. The
codebase has been re-written in Python (save for some external libraries, which
remain in their native Fortran), utilising the object-oriented features of the
language, and improving the modularity of the code. Pre-written scripts are
provided for running the simulations in `standard' modes of operation, but the
code is flexible enough to support the writing of personalised scripts. The
modular structure also makes the addition of experimental features (such as new
models for period or luminosity distributions) more straightforward than with
the previous code.
  We also discuss potential additions to the modelling capabilities of the
software. Finally, we demonstrate some potential applications of the code;
first, using results of surveys at different observing frequencies, we find
pulsar spectral indices are best fit by a normal distribution with mean $-1.4$
and standard deviation $1.0$. Second, we model pulsar spin evolution to
calculate the best-fit for a relationship between a pulsar's luminosity and
spin parameters. We used the code to replicate the analysis of
Faucher-Gigu\`ere & Kaspi, and have subsequently optimized their power-law
dependence of radio luminosity, $L$, with period, $P$, and period derivative,
$\dot{P}$. We find that the underlying population is best described by $L
\propto P^{-1.39 \pm 0.09} \dot{P}^{0.48 \pm 0.04}$ and is very similar to that
found for $\gamma$-ray pulsars by Perera et al. Using this relationship, we
generate a model population and examine the age-luminosity relation for the
entire pulsar population, which may be measurable after future large-scale
surveys with the Square Kilometer Array.


title:
Low-complexity End-to-End Performance Optimization in MIMO Full-Duplex
  Relay Systems

abstract:
  In this paper, we deal with the deployment of full-duplex relaying in
amplify-and-forward (AF) cooperative networks with multiple-antenna terminals.
In contrast to previous studies, which focus on the spatial mitigation of the
loopback interference (LI) at the relay node, a joint precoding/decoding design
that maximizes the end-to-end (e2e) performance is investigated. The proposed
precoding incorporates rank-1 zero-forcing (ZF) LI suppression at the relay
node and is derived in closed-form by solving appropriate optimization
problems. In order to further reduce system complexity, the antenna selection
(AS) problem for full-duplex AF cooperative systems is discussed. We
investigate different AS schemes to select a single transmit antenna at both
the source and the relay, as well as a single receive antenna at both the relay
and the destination. To facilitate comparison, exact outage probability
expressions and asymptotic approximations of the proposed AS schemes are
provided. In order to overcome zero-diversity effects associated with the AS
operation, a simple power allocation scheme at the relay node is also
investigated and its optimal value is analytically derived. Numerical and
simulation results show that the joint ZF-based precoding significantly
improves e2e performance, while AS schemes are efficient solutions for
scenarios with strict computational constraints.


title: Hydrodynamic surrogate models for bio-inspired micro-swimming robots

abstract:
  Research on untethered micro-swimming robots is growing fast owing to their
potential impact on minimally invasive medical procedures. Candidate propulsion
mechanisms of robots are based on flagellar mechanisms of microorganisms such
as rotating rigid helices and traveling plane-waves on flexible rods and
parameterized by wavelength, amplitude, and frequency. For design and control
of swimming robots, accurate real-time models are necessary to compute
trajectories, velocities and hydrodynamic forces acting on robots. Resistive
force theory (RFT) provides an excellent framework for the development of
real-time six degrees-of-freedom surrogate models for design optimization and
control. However, the accuracy of RFT-based models depends strongly on
hydrodynamic interactions. Here, we introduce interaction coefficients that
only multiply body resistance coefficients with no modification to local
resistance coefficients on the tail. Interaction coefficients are obtained for
a single specimen of Vibrio Algino reported in the literature, and used in the
RFT model for comparisons of the forward-swimming component of the resultant
velocities and body rotation rates against other specimens. Furthermore, CFD
simulations are used to obtain forward and lateral velocities and body rotation
rates of bio-inspired swimmers with helical tails and traveling-plane waves for
a range of amplitudes and wavelengths. Interaction coefficients are obtained
from the CFD simulation for the helical tail with the specified amplitude and
wavelength and used in the RFT model for comparisons of velocities and body
rotation rates for other designs. Comparisons indicate that hydrodynamic models
that employ interaction coefficients prove to be viable surrogates for
computationally intensive three-dimensional time-dependent CFD models.


title:
Distinct-symmetry spin liquid states and phase diagram of Kitaev-Hubbard
  model

abstract:
  We report the finding of a series of symmetry distinct spin liquid (SL)
states and a rich phase diagram in a half-filled honeycomb lattice Hubbard
model with spin-dependent hopping amplitude t'. We first study the magnetic
instability of the system and find two antiferromagnetic orders beyond a
critical Hubbard U which increases with the ratio t'/t . For $t'$ approaching
to $t$, the semimetal (SM) transforms to a U(1) SL and then to the Kitaev Z_2
SL as U increases. In a wide middle range of t'/t, the latter is replaced by a
U(1) SL to $SU(2)$ SL transition. The physical properties of the stable SL
phases are discussed.


title:
Observations of 6.7 GHz Methanol Masers with EAVN I: VLBI Images of the
  first Epoch of Observations

abstract:
  Very long baseline interferometry (VLBI) monitoring of the 6.7 GHz methanol
maser allows us to measure the internal proper motions of the maser spots and
therefore study the gas motion around high-mass young stellar objects. To this
end, we have begun monitoring observations with the East-Asian VLBI Network. In
this paper we present the results of the first epoch observation for 36
sources, including 35 VLBI images of the methanol maser. Since two independent
sources were found in three images, respectively, images of 38 sources were
obtained. In 34 sources, more than or equal to 10 spots were detected. The
observed spatial scale of the maser distribution was from 9 to 4900
astronomical units, and the following morphological categories were observed:
elliptical, arched, linear, paired, and complex. The position of the maser spot
was determined to an accuracy of approximately 0.1 mas, sufficiently high to
measure the internal proper motion from two years of monitoring observations.
The VLBI observation, however, detected only approximately 20% of all maser
emission, suggesting that the remaining 80% of the total flux was spread into
an undetectable extended distribution. Therefore, in addition to
high-resolution observations, it is important to observe the whole structure of
the maser emission including extended low-brightness structures, to reveal the
associated site of the maser and gas motion.


title:
High-order Foldy-Wouthuysen transformations of the Dirac and Dirac-Pauli
  Hamiltonians in the weak-field limit

abstract:
  The low-energy and weak-field limit of Dirac equation can be obtained by an
order-by-order block diagonalization approach to any desired order in the
parameter $\pi/mc$ ($\pi$ is the kinetic momentum and $m$ is the mass of the
particle). In the previous work, it has been shown that, up to the order of
$(\pi/mc)^8$, the Dirac-Pauli Hamiltonian in the Foldy-Wouthuysen (FW)
representation may be expressed as a closed form and consistent with the
classical Hamiltonian, which is the sum of the classical relativistic
Hamiltonian for orbital motion and the Thomas-Bargmann-Michel-Telegdi (T-BMT)
Hamiltonian for spin precession. In order to investigate the exact validity of
the correspondence between classical and Dirac-Pauli spinors, it is necessary
to proceed to higher orders. In this paper, we investigate the FW
representation of the Dirac and Dirac-Pauli Hamiltonians by using Kutzelnigg's
diagonalization method. We show that the Kutzelnigg diagonalization method can
be further simplified if nonlinear effects of static and homogeneous
electromagnetic fields are neglected (in the weak-field limit). Up to the order
of $(\pi/mc)^{14}$, we find that the FW transformation for both Dirac and
Dirac-Pauli Hamiltonians is in agreement with the classical Hamiltonian with
the gyromagnetic ratio given by $g=2$ and $g\neq2$ respectively. Furthermore,
with higher-order terms at hand, it is demonstrated that the unitary FW
transformation admits a closed form in the low-energy and weak-field limit.


title: Chiral expansion of nucleon PDF at $x\sim m_\pi/M_N$

abstract:
  Based on the chiral perturbation theory, we investigate the low-energy
dynamics of nucleon parton distributions. We show that in different regions of
the momentum fraction $x$ the chiral expansion is significantly different. For
nucleon parton distributions these regions are characterized by $x\sim1$,
$x\sim m_\pi/M_N$ and $x\sim (m_\pi/M_N)^2$. We derive extended counting rules
for each region and obtain model-independent results for the nucleon parton
distributions down to $x\gtrsim m^2_\pi/M^2_N \approx 10^{-2}$.


title:
Non-perturbative treatment of strongly-interacting fields: insights from
  liquid theory

abstract:
  We outline a new programme of solving the problem of treating strong
interactions in field theories. The programme does not involve perturbation
theories and associated problems of divergences. We apply our recent idea of
treating strongly interacting liquids to field theories by showing the
equivalence of Hamiltonians of liquids and interacting fields. In this
approach, the motion of the field results in the disappearance of $n-1$
transverse modes with frequency smaller than the Frenkel frequency $\omega_{\rm
F}$, similar to the loss of two transverse modes in a liquid with frequency
$\omega<\omega_{\rm F}$. We illustrate the proposed programme with the
calculation of the energy and propagator, and show that the results can not be
obtained in perturbation theory to any finite order. Importantly, the Frenkel
energy gap $E_{\rm F}=\hbar\omega_{\rm F}$ and the associated massive Frenkel
particle naturally appear in our consideration, the result that is relevant for
current efforts to demonstrate a mass gap in interacting field theories such as
Yang-Mills theory. Notably, our mechanism involves a physically sensible
starting point in terms of real masses (frequencies) in the harmonic
non-interacting field, in contrast to the Higgs effect involving the imaginary
mass as a starting point. We further note that the longitudinal mode in our
approach remains gapless, implying that both short-range and long-range forces
with massive and massless particles naturally emerge and unify in a single
interacting field, a result not hitherto anticipated. Finally, we comment on
the relationship between our results and hydrodynamic description of the
quark-gluon plasma.

categories: hep-th cond-mat.stat-mech hep-lat hep-ph


title:
Cosmological dynamics and dark energy from non-local infrared
  modifications of gravity

abstract:
  We perform a detailed study of the cosmological dynamics of a recently
proposed infrared modification of the Einstein equations, based on the
introduction of a non-local term constructed with $m^2g_{\mu\nu}\Box^{-1} R$,
where $m$ is a mass parameter. The theory generates automatically a dynamical
dark energy component, that can reproduce the observed value of the dark energy
density without introducing a cosmological constant. Fixing $m$ so to reproduce
the observed value $\Omega_{\rm DE}\simeq 0.68$, and writing $w(a)=w_0+(1-a)
w_a$, the model provides a neat prediction for the equation of state parameters
of dark energy, $w_0\simeq -1.042$ and $w_a\simeq -0.020$. We show that,
because of some freedom in the definition of $\Box^{-1}$, one can extend the
construction so to define a more general family of non-local models. However,
in a first approximation this turns out to be equivalent to adding an explicit
cosmological constant term on top of the dynamical dark energy component. This
leads to an extended model with two parameters, $\Omega_{\Lambda}$ and $m$.
Even in this extension the EOS parameter $w_0$ is always on the phantom side,
in the range $-1.33 < w_0\leq -1$, and there is a prediction for the relation
between $w_0$ and $w_a$.


title:
Distinguishing the right-handed up/charm quarks from top quark via
  discrete symmetries in the standard model extensions

abstract:
  We propose a class of the two Higgs doublet Standard models (SMs) with a SM
singlet and a class of supersymmetric SMs with two pairs of Higgs doublets,
where the right-handed up/charm quarks and the right-handed top quark have
different quantum numbers under extra discrete symmetries. Thus, the
right-handed up and charm quarks couple to one Higgs doublet field, while the
right-handed top quark couples to another Higgs doublet. The quark CKM mixings
can be generated from the down-type quark sector. As one of phenomenological
consequences in our models, we explore whether one can accommodate the observed
direct CP asymmetry difference in singly Cabibbo-suppressed D decays. We show
that it is possible to explain the measured values of CP violation under
relevant experimental constraints.


title:
Existence theorem for hyperbolic quasiperiodic solutions of Lagrangian
  systems on Riemannian manifolds

abstract:
  We establish new sufficient conditions for the existence of classical
hyperbolic quasiperiodic solutions for natural Lagrangian system on Riemannian
manifold with time-quasiperiodic force function


title:
Robust Constraint on a Drifting Proton-to-Electron Mass Ratio at z=0.89
  from Methanol Observation at Three Radio Telescopes

abstract:
  A limit on a possible cosmological variation of the proton-to-electron mass
ratio $\mu$ is derived from methanol (CH$_3$OH) absorption lines in the
benchmark PKS1830$-$211 lensing galaxy at redshift $z = 0.89$ observed with the
Effelsberg 100-m radio telescope, the Institute de Radio Astronomie
Millim\'{e}trique 30-m telescope, and the Atacama Large
Millimeter/submillimeter Array. Ten different absorption lines of CH$_3$OH
covering a wide range of sensitivity coefficients $K_{\mu}$ are used to derive
a purely statistical 1-$\sigma$ constraint of $\Delta\mu/\mu = (1.5 \pm 1.5)
\times 10^{-7}$ for a lookback time of 7.5 billion years. Systematic effects of
chemical segregation, excitation temperature, frequency dependence and time
variability of the background source are quantified. A multi-dimensional linear
regression analysis leads to a robust constraint of $\Delta\mu/\mu = (-1.0 \pm
0.8_{\rm stat} \pm 1.0_{\rm sys}) \times 10^{-7}$.


title:
Helical multiferroics for electric field controlled quantum information
  processing

abstract:
  Magnetoelectric coupling in helical multiferroics allows to steer spin order
with electric fields. Here we show theoretically that in a helical multiferroic
chain quantum information processing as well as quantum phases are highly
sensitive to electric (E) field. Applying E-field, the quantum state transfer
fidelity can be increased and made directionally dependent.
  We also show that E field transforms the spin-density-wave/nematic or
multipolar phases of frustrated ferromagnetic spin-1/2 chain in chiral phase
with a strong magnetoelectric coupling. We find sharp reorganization of the
entanglement spectrum as well as a large enhancement of fidelity susceptibility
at Ising quantum phase transition from nematic to chiral states driven by
electric field. These findings point to a new tool for quantum information with
low power consumption.


title:
Embedding parameters in ab initio theory to develop well-controlled
  approximations based on molecular similarity

abstract:
  A means to take advantage of molecular similarity to lower the computational
cost of electronic structure theory is proposed, in which parameters are
embedded into a low-cost, low-level (LL) ab initio theory and adjusted to
obtain agreement with a higher level (HL) ab initio theory. This approach is
explored by training such a model on data for ethane and testing the resulting
model on methane, propane and butane. The electronic distribution of the
molecules is varied by placing them in strong electrostatic environments
consisting of random charges placed on the corners of a cube. The results find
that parameters embedded in HF/STO-3G theory can be adjusted to obtain
agreement, to within about 2 kcal/mol, with results of HF/6-31G theory.
Obtaining this level of agreement requires the use of parameters that are
functions of the bond lengths, atomic charges, and bond orders within the
molecules. The argument is made that this approach provides a well-controlled
means to take advantage of molecular similarity in quantum chemistry.


title: Weak-localization approach to a 2D electron gas with a spectral node

abstract:
  We study a weakly disordered 2D electron gas with two bands and a spectral
node within the weak-localization approach and compare its results with those
of Gaussian fluctuations around the self-consistent Born approximation. The
appearance of diffusive modes depends on the type of disorder. In particular,
we find for a random gap a diffusive mode only from ladder contributions,
whereas for a random scalar potential the diffusive mode is created by ladder
and by maximally crossed contributions. The ladder (maximally crossed)
contributions correspond to fermionic (bosonic) Gaussian fluctuations. We
calculate the conductivity corrections from the density--density Kubo formula
and find a good agreement with the experimentally observed V-shape conductivity
of graphene.


title:
Determining the masses of invisible particles: Application to Higgs
  boson invisible decay

abstract:
  To know the total width of the recently discovered Higgs boson particle, it
is important to measure the invisible decay width of the Higgs boson. However,
the signal for this measurement at the LHC, i.e., a charged lepton pair and
missing energy in the final state, cannot be definitely understood as the
product of the intermediate produced $Z$ and $H$ bosons due to the possible
interaction between dark matter and a $Z$ boson or quarks, which can be
described by representative effective operators. First, we consider the relic
abundance, the LUX direct detection experiment and the result of searching for
Higgs boson invisible decay at the LEP and LHC to find the allowed parameter
region for the effective operators. Then we investigate the transverse momentum
distribution of the missing energy and propose two observables that can be used
to distinguish the different underlying processes. Moreover, with these two
observables, we may be able to determine the masses of invisible particles.


title:
Well-posedness of a fully-coupled Navier-Stokes/Q-tensor system with
  inhomogeneous boundary data

abstract:
  We prove short-time well-posedness and existence of global weak solutions of
the Beris--Edwards model for nematic liquid crystals in the case of a bounded
domain with inhomogeneous mixed Dirichlet and Neumann boundary conditions. The
system consists of the Navier-Stokes equations coupled with an evolution
equation for the $Q$-tensor. The solutions possess higher regularity in time of
order one compared to the class of weak solutions with finite energy. This
regularity is enough to obtain Lipschitz continuity of the non-linear terms in
the corresponding function spaces. Therefore the well-posedness is shown with
the aid of the contraction mapping principle using that the linearized system
is an isomorphism between the associated function spaces.


title:
Silicon isotopic abundance toward evolved stars and its application for
  presolar grains

abstract:
  Galactic chemical evolution (GCE) is important for understanding the
composition of the present-day interstellar medium (ISM) and of our solar
system. In this paper, we aim to track the GCE by using the 29Si/30Si ratios in
evolved stars and tentatively relate this to presolar grain composition. We
used the APEX telescope to detect thermal SiO isotopologue emission toward four
oxygen-rich M-type stars. Together with the data retrieved from the Herschel
science archive and from the literature, we were able to obtain the 29Si/30Si
ratios for a total of 15 evolved stars inferred from their optically thin 29SiO
and 30SiO emission. These stars cover a range of masses and ages, and because
they do not significantly alter 29Si/30Si during their lifetimes, they provide
excellent probes of the ISM metallicity (or 29Si/30Si ratio) as a function of
time. The 29Si/30Si ratios inferred from the thermal SiO emission tend to be
lower toward low-mass oxygen-rich stars (e.g., down to about unity for W Hya),
and close to an interstellar or solar value of 1.5 for the higher-mass carbon
star IRC+10216 and two red supergiants. There is a tentative correlation
between the 29Si/30Si ratios and the mass-loss rates of evolved stars, where we
take the mass-loss rate as a proxy for the initial stellar mass or current
stellar age. This is consistent with the different abundance ratios found in
presolar grains. We found that older objects (up to possibly 10 Gyr old) in our
sample trace a previous, lower 29Si/30Si value of about 1. Material with this
isotopic ratio is present in two subclasses of presolar grains, providing
independent evidence of the lower ratio. Therefore, the 29Si/30Si ratio derived
from the SiO emission of evolved stars is a useful diagnostic tool for the
study of the GCE and presolar grains.