title:
Phonon-mediated Casimir interaction between mobile impurities in
  one-dimensional quantum liquids

abstract:
  Virtual phonons of a quantum liquid scatter off impurities and mediate a
long-range interaction, analogous to the Casimir effect. In one dimension the
effect is universal and the induced interaction decays as $1/r^3$, much slower
than the van der Waals interaction $\sim1/r^6$, where $r$ is the impurity
separation. The sign of the effect is characterized by the product of
impurity-phonon scattering amplitudes, which take a universal form and have
been seen to vanish for several integrable impurity models. Thus, if the
impurity parameters can be independently tuned to lie on opposite sides of such
integrable points, one can observe an attractive interaction turned into a
repulsive one.


title:
Autour de la d\'ecomposition de Dunford r\'eelle ou complexe. Th\'eorie
  spectrale et m\'ethodes effectives

abstract:
  These notes are not intended to substitute for a course in linear algebra on
reduction of endomorphisms nor an exhaustive presentation of the Dunford's
decomposition. We will limit ourselves to the case where the base is R or C,
and the purpose of this presentation is to make an inventory of the various
Dunford's decomposition methods. When the eigenvalues are known with their
exact values, decomposition into simple elements of the inverse of a polynomial
annihilator provides us the spectral projectors and a fortiori the expected
decomposition. The most difficult case occurs when the spectrum of the
endomorphism is not at our disposal, which is a common situation when the
dimension of the vector space is greater than 4. The Newton-Raphson method then
comes to the rescue to provide a sequence which converges quadratically to
diagonalizable component. While this method is very popular quite effective
regardless of the size matrix studied, but it leaves us hungry. Indeed, we know
that Dunford components are polynomials in the matrix and would know these
generator polynomials. The good news is that effective method using the Chinese
lemma there and it was introduced by Chevalley in the fifty years of the
century last. I will focus on this method which was mentioned in an article of
Danielle Couty, Jean Esterle and Rachid Zarouf, detailing evidence of the
algorithm where the characteristic polynomial is divided on the body base, then
I will detail the actual case is a more subtle situation requiring further
study. A reminder of the semi-simple endomorphisms was introduced to justify
the importance of finding an effective method for testing diagonalisability in
Mn (R) when no eigenvalues of the endomorphism studied. To achieve this I have
proposed as the Sturm verification tool diagonalisabilit\'e in R.


title: First Observation of the $\Lambda(1405)$ Line Shape in Electroproduction

abstract:
  We report the first observation of the line shape of the $\Lambda(1405)$ from
electroproduction, and show that it is not a simple Breit-Wigner resonance.
Electroproduction of $K^+ \Lambda(1405)$ off the proton was studied by using
data from CLAS at Jefferson Lab in the range $1.0<Q^2<3.0$ (GeV/c)$^2$. The
analysis utilized the decay channels $\Sigma^+ \pi^-$ of the $\Lambda(1405)$
and $p \pi^0$ of the $\Sigma^+$. Neither the standard (PDG) resonance
parameters, nor free parameters fitting to a single Breit-Wigner resonance
represent the line shape. In our fits, the line shape corresponds approximately
to predictions of a two-pole meson-baryon picture of the $\Lambda(1405)$, with
a lower mass pole near 1368 MeV/c$^2$ and a higher mass pole near 1423
MeV/c$^2$. Furthermore, with increasing photon virtuality the mass distribution
shifts toward the higher mass pole.


title:
Quark masses, mixings, and CP violation from spontaneous breaking of
  flavor $SU(3)^{3}$

abstract:
  A ${\cal G}_{\cal F}=SU(3)_{Q}\times SU(3)_{u}\times SU(3)_{d}$ invariant
scalar potential breaking spontaneously the quark flavor symmetry can explain
the standard model flavor puzzle. The approximate alignment in flavor space of
the vacuum expectation values of the up and down ``Yukawa fields'' is explained
as a dynamical effect, and the observed quark mixing angles, the weak CP
violating phase, and hierarchical quark masses can be reproduced without
introducing hierarchical parameters.


title: Correlating toughness and roughness in ductile fracture

abstract:
  Three dimensional calculations of ductile crack growth under mode I plane
strain, small scale yielding conditions are carried out using an
elastic-viscoplastic constitutive relation for a progres- sively cavitating
plastic solid with two populations of void nucleating second phase particles.
Full field solutions are obtained for three dimensional material
microstructures characterized by ran- dom distributions of void nucleating
particles. Crack growth resistance curves and fracture surface roughness
statistics are calculated using standard procedures. The range of void
nucleating particle volume fractions considered give rise to values of
toughness, JIC, that vary by a factor of four. For all volume fractions
considered, the computed fracture surfaces are self-affine over a size range of
about two orders of magnitude with a roughness exponent of 0.54 $\pm$ 0.03. For
small void nucleating particle volume fractions, the mean large particle
spacing serves as a single dominant length scale. In this regime, the
correlation length of the fracture surface corresponding to the cut-off of the
self-affine behavior is found to be linearly related to JIC thus quantitatively
correlating toughness and fracture surface roughness.


title:
Exploring the Gamma-Ray Emissivity of Young Supernova Remnants I:
  Hadronic Emission

abstract:
  Using a simplified model for the hadronic emission from young supernova
remnants (SNRs), we derive an expression to calculate the hadronic luminosity
with time, depending on the SN ejecta density profile and the density structure
of the surrounding medium. Our analysis shows that the hadronic emission will
decrease with time for core-collapse SNe expanding in the winds of their
progenitor stars, but increase with time for SNe expanding into a constant
density medium, typical of Type Ia SNe. Using our expressions, we can compute
the time-dependent hadronic flux from some well-known young SNe and SNRs with
time, and where applicable reproduce previous results in the appropriate
parameter regime. Using our calculations, we also emphasize the exciting
possibility that SN 1987A may become a visible gamma-ray source in the next
decade.


title:
No early warning signals for stochastic transitions: insights from large
  deviation theory

abstract:
  A reply to Drake (2013) "Early warning signals of stochastic switching"
http://dx.doi.org/10.1098/rspb.2013.0686


title: Stability of viscous weak detonation waves for Majda's model

abstract:
  Continuing the program initiated by Humpherys, Lyng, & Zumbrun [17] for
strong detonation waves, we use a combination of analytical and numerical
Evans-function techniques to analyze the spectral stability of weak detonation
waves in a simplified model for gas-dynamical combustion. Combining these new
spectral stability results with the pointwise Green function analysis of Lyng,
Raoofi, Texier, & Zumbrun [22], we conclude that these waves are nonlinearly
stable. The principal novelty of this analysis is the treatment of weak
detonation waves. In contrast to the case of strong detonation waves, weak
detonation waves are undercompressive and the stability of these waves is
delicate and has not been treated by standard weighted-norm techniques. The
present analysis thus provides a case study illustrating the flexibility and
power of the Evans-function- based approach to stability. As in the case of
strong detonations, we find that all tested waves are spectrally stable, hence
nonlinearly stable.


title: Re-imagining the Hardy-Weinberg Law

abstract:
  Under random mating, a progeny's alleles are independently sampled from the
parental gene pools. Here is a new proof which avoids the usual algebraic
complexity, based on a restated Mendel's First Law. Another simplified proof
along the old approach led to the discovery that allelic independence can hold
under random mating and fertility selection. The theoretical existence and
number of such selection coefficients are established.


title:
Gravitational Waveforms for Precessing, Quasicircular Compact Binaries
  with Multiple Scale Analysis: Small Spin Expansion

abstract:
  We obtain analytical gravitational waveforms in the frequency-domain for
precessing, quasi-circular compact binaries with small spins, applicable, for
example, to binary neutron star inspirals. We begin by calculating an analytic
solution to the precession equations, obtained by expanding in the
dimensionless spin parameters and using multiple-scale analysis to separate
timescales. We proceed by analytically computing the Fourier transform of
time-domain waveform through the stationary phase approximation. We show that
the latter is valid for systems with small spins. Finally, we show that these
waveforms have a high overlap with numerical waveforms obtained through direct
integration of the precession equations and discrete Fourier transformations.
The resulting, analytic waveform family is ideal for detection and parameter
estimation of gravitational waves emitted by inspiraling binary neutron stars
with ground-based detectors.


title: Spectral data for U(m,m)-Higgs bundles

abstract:
  We define and study spectral data associated to U(m,m)-Higgs bundles through
the Hitchin fibration. We give a new interpretation of the topological
invariants involved, as well as a geometric description of the moduli space.


title: On the Complexity of a Matching Problem with Asymmetric Weights

abstract:
  We present complexity results regarding a matching-type problem related to
structural controllability of dynamical systems modelled on graphs.
Controllability of a dynamical system is the ability to choose certain inputs
in order to drive the system from any given state to any desired state; a graph
is said to be structurally controllable if it represents the structure of a
controllable system. We define the Orientation Control Matching problem (OCM)
to be the problem of orienting an undirected graph in a manner that maximizes
its structural controllability. A generalized version, the Asymmetric
Orientation Control Matching problem (AOCM), allows for asymmetric weights on
the possible directions of each edge. These problems are closely related to
2-matchings, disjoint path covers, and disjoint cycle covers. We prove using
reductions that OCM is polynomially solvable, while AOCM is much harder; we
show that it is NP-complete as well as APX-hard.


title:
Characteristic Length of Energy-Containing Structures at the Base of a
  Coronal Hole

abstract:
  An essential parameter for models of coronal heating and fast solar wind
acceleration that rely on the dissipation of MHD turbulence is the
characteristic energy-containing length $\lambda_{\bot}$ of the squared
velocity and magnetic field fluctuations ($u^2$ and $b^2$) transverse to the
mean magnetic field inside a coronal hole (CH) at the base of the corona. The
characteristic length scale defines directly the heating rate. We use a time
series analysis of solar granulation and magnetic field measurements inside two
CHs obtained with the New Solar Telescope (NST) at Big Bear Solar Observatory.
A data set for transverse magnetic fields obtained with the Solar Optical
Telescope/Spectro-Polarimeter (SOT/SP) aboard {\it Hinode} spacecraft was
utilized to analyze the squared transverse magnetic field fluctuations $b_t^2$.
Local correlation tracking (LCT) was applied to derive the squared transverse
velocity fluctuations $u^2$. We find that for $u^2$-structures, Batchelor
integral scale $\lambda$ varies in a range of 1800 - 2100 km, whereas the
correlation length $\varsigma$ and the $e$-folding length $L$ vary between 660
and 1460 km. Structures for $b_t^2$ yield $\lambda \approx 1600$ km, $\varsigma
\approx 640$ km, and $L \approx 620$ km. An averaged (over $\lambda,
\varsigma$, and $L$) value of the characteristic length of $u^2$-fluctuations
is 1260$\pm$500 km, and that of $b_t^2$ is 950$\pm$560 km. The characteristic
length scale in the photosphere is approximately 1.5-50 times smaller than that
adopted in previous models (3-30$\times10^3$ km). Our results provide a
critical input parameter for current models of coronal heating and should yield
an improved understanding of fast solar wind acceleration.


title: Time-reversal of reflected Brownian motions in the orthant

abstract:
  We determine the processes obtained from a large class of reflected Brownian
motions (RBMs) in the nonnegative orthant by means of time reversal. The class
of RBMs we deal with includes, but is not limited to, RBMs in the so-called
Harrison-Reiman class [4] having diagonal covariance matrices. For such RBMs
our main result resolves the long-standing open problem of determining the time
reversal of RBMs beyond the skew-symmetric case treated by R.J. Williams in
[16]. In general, the time-reversed process itself is no longer a RBM, but its
distribution is absolutely continuous with respect to a certain auxiliary RBM.
In the course of the proof we introduce a novel discrete approximation scheme
for the class of RBMs described above, and use it to determine the semigroups
dual to the semigroups of such RBMs.


title:
Addressing Integration Error for Polygonal Finite Elements Through
  Polynomial Projections: A Patch Test Connection

abstract:
  Polygonal finite elements generally do not pass the patch test as a result of
quadrature error in the evaluation of weak form integrals. In this work, we
examine the consequences of lack of polynomial consistency and show that it can
lead to a deterioration of convergence of the finite element solutions. We
propose a general remedy, inspired by techniques in the recent literature of
mimetic finite differences, for restoring consistency and thereby ensuring the
satisfaction of the patch test and recovering optimal rates of convergence. The
proposed approach, based on polynomial projections of the basis functions,
allows for the use of moderate number of integration points and brings the
computational cost of polygonal finite elements closer to that of the commonly
used linear triangles and bilinear quadrilaterals. Numerical studies of a
two-dimensional scalar diffusion problem accompany the theoretical
considerations.


title:
Conformal field theory of dipolar SLE with the Dirichlet boundary
  condition

abstract:
  We develop a version of dipolar conformal field theory based on the central
charge modification of the Gaussian free field with the Dirichlet boundary
condition and prove that correlators of certain family of fields in this theory
are martingale-observables for dipolar SLE. We prove the restriction property
of dipolar SLE(8/3) and Friedrich-Werner's formula in the dipolar case.


title: H\alpha\ Absorption in Transiting Exoplanet Atmospheres

abstract:
  Absorption of stellar H\alpha\ by the upper atmosphere of the planet
HD189733b has recently been detected by Jensen et al. Motivated by this
observation, we have developed a model for atomic hydrogen in the n=2 state and
compared the resulting H\alpha\ line profile to the observations. The model
atmosphere is in hydrostatic balance, as well as thermal and photoionization
equilibrium. Collisional and radiative transitions are included in the
determination of the n=2 state level population. We find that H\alpha\
absorption is dominated by an optical depth \tau\ ~ 1 shell, composed of
hydrogen in the metastable 2s state that is located below the hydrogen
ionization layer. The number density of the 2s state within the shell is found
to vary slowly with radius, while that of the 1s state falls rapidly. Thus
while the Ly\alpha absorption, for a certain wavelength, occurs inside a
relatively well defined impact parameter, the contribution to H\alpha\
absorption is roughly uniform over the entire atomic hydrogen layer. The model
can approximately reproduce the observed Ly\alpha\ and H\alpha\ integrated
transit depths for HD189733b by using an ionization rate enhanced over that
expected for the star by an order of magnitude. For HD 209458b, we are unable
to explain the asymmetric H\alpha\ line profile observed by Jensen et al., as
the model produces a symmetric line profile with transit depth comparable to
that of HD 189733b. In an appendix, we study the effect of the stellar
Ly\alpha\ absorption on the net cooling rate.


title: Nonequilibrium spin noise spectroscopy

abstract:
  Spin Noise Spectroscopy (SNS) is an experimental approach to obtain
correlators of mesoscopic spin fluctuations in time by purely optical means. We
explore the information that this technique can provide when it is applied to a
weakly non-equilibrium regime when an electric current is driven through a
sample by an electric field. We find that the noise power spectrum of
conducting electrons experiences a shift, which is proportional to the strength
of the spin-orbit coupling for electrons moving along the electric field
direction. We propose applications of this effect to measurements of spin orbit
coupling anisotropy and separation of spin noise of conducting and localized
electrons.


title: Gluon dissociation of J/psi beyond the dipole approximation

abstract:
  Using a nonrelativistic potential model, we calculate the cross section for
the leading-order gluon dissociation of J/psi by including the full gluon wave
function. We find that the resulting cross section as a function of gluon
energy is reduced by about a factor of three at its maximum value compared to
that calculated in the dipole approximation that is usually adopted in
theoretical studies. The effect of the reduced cross section on the J/psi
dissociation width at finite temperature is also discussed.


title: Selective nucleation in porous media

abstract:
  Geometrical arguments suggest that pore-mediated nucleation happens in
general in a two-step fashion, the first step being nucleation within the pore,
the second being nucleation from the filled pore into solution [Page & Sear,
Phys. Rev. Lett. 97, 65701 (2006)]. The free energy barriers controlling the
two steps of this process show opposite dependencies on pore size, implying
that for given thermodynamic conditions there exists a pore size for which
nucleation happens fastest. Here we show, within the two- and three-dimensional
Ising lattice gas, that this preferred pore size tracks the size of the bulk
critical nucleus, up to a numerical prefactor. This observation suggests a
simple prescription for directing nucleation to certain locations within
heterogeneous porous media.


title:
The Magellan Uniform Survey of Damped Lyman alpha Systems I: Cosmic
  Metallicity Evolution

abstract:
  We present the chemical abundance measurements of the first large,
medium-resolution, uniformly selected damped Lyman alpha system (DLA) survey.
The sample contains 99 DLAs towards 89 quasars selected from the SDSS DR5 DLA
sample in a uniform way. We analyze the metallicities and kinematic
diagnostics, including the velocity width of 90% of the optical depth, \Delta
v_{90}, and the equivalent widths of the SiII 1526, CIV 1548 and MgII 2796
transitions. To avoid strong line-saturation effects on the metallicities
measured in medium-resolution spectra (FWHM~71 km/s), we derived metallicities
from metal transitions which absorbed at most 35% of the quasar continuum flux.
We find the evolution in cosmic mean metallicity of the sample, <Z> = (-0.04 +-
0.013)z -(1.06 +- 0.36), consistent with no evolution over the redshift range z
~ [2.2, 4.4], but note that the majority of our sample falls at z ~ [2.2, 3.5].
The apparent lack of metallicity evolution with redshift is also seen in a lack
of evolution in the median \Delta v_{90} and SiII 1526 equivalent width values.
While this result may seem to conflict with other large surveys that have
detected significant metallicity evolution, such as Rafelski et al. 2012 who
found <Z> = (-0.22 +- 0.03)z - (0.65 +- 0.09) over z ~ [0, 5], several tests
show that these surveys are not inconsistent with our new result. However, over
the smaller redshift range covered by our uniformly-selected sample, the true
evolution of the cosmic mean metallicity in DLAs may be somewhat flatter than
the Rafelski et al. 2012 estimate.


title:
Modulation Classification of MIMO-OFDM Signals by Independent Component
  Analysis and Support Vector Machines

abstract:
  A modulation classification (MC) scheme based on Independent Component
Analysis (ICA) in conjunction with either maximum likelihood (ML) or Support
Vector Machines (SVM) is proposed for MIMO-OFDM signals over frequency
selective, time varying channels. The method is blind in the sense that it is
assumed that the receiver has no information about the channel and transmitted
signals other than that the spatial streams of signals are statistically
independent. The processing consists of separation of the MIMO streams followed
by modulation classification of the separated signals. While in general, blind
separation of signals over frequency selective channels is a difficult problem,
the non-frequency selective nature of the channel experienced by individual
symbols in a MIMO-OFDM system enables the application of well-known ICA
algorithms. Modulation classification is implemented by maximum likelihood and
by an SVM-based modulation classification method relying on pre-selected
modulation-dependent features. To improve performance in time varying channels,
the invariance of the channel is exploited across the coherence bandwidth and
the time coherence. The proposed method is shown to perform with high
probability of correct classification over realistic ITU pedestrian and
vehicular channels. An upper bound on the probability of correct classification
is developed based on the Cramer Rao bound of channel estimation.


title: A note on the generalized Bernoulli and Euler Polynomials

abstract:
  In this paper we use probabilistic methods to derive some results on the
generalized Bernoulli and generalized Euler polynomials. Our approach is based
on the properties of Appell polynomials associated with uniformly distributed
and Bernoulli distributed random variables and their sums.


title:
DarkLight: A Search for Dark Forces at the Jefferson Laboratory
  Free-Electron Laser Facility

abstract:
  We give a short overview of the DarkLight detector concept which is designed
to search for a heavy photon A' with a mass in the range 10 MeV/c^2 < m(A') <
90 MeV/c^2 and which decays to lepton pairs. We describe the intended operating
environment, the Jefferson Laboratory free electon laser, and a way to extend
DarkLight's reach using A' --> invisible decays.


title:
Influence of the Core/Shell Interface on Biexciton Auger Recombination
  in Individual Nanocrystal Quantum Dots

abstract:
  Previous single-particle spectroscopic studies of colloidal quantum dots have
indicated a significant spread in biexciton lifetimes across an ensemble of
nominally identical nanocrystals. It has been speculated that in addition to
dot-to-dot variation in physical dimensions, this spread is contributed to by
variations in the structure of the quantum dot interface, which controls the
shape of the confinement potential. Here we directly evaluate the effect of the
composition of the core-shell interface on single- and multi-exciton dynamics
via side-by-side measurements of individual core-shell CdSe-CdS nanocrystals
with a sharp vs. smooth (graded) interface. To realize the latter type of
structures, we incorporate a CdSexS1-x alloy layer of controlled composition
and thickness between the CdSe core and the CdS shell. We observe that while
having essentially no effect on single-exciton decay, the interfacial alloy
layer leads to a systematic increase in biexciton lifetimes. This observation
provides direct experimental evidence that in addition to the size of the
quantum dot, its interfacial properties also significantly affect the rate of
Auger recombination, which governs biexciton decay. These findings help
rationalize previous observations of a significant heterogeneity in the
biexciton lifetimes across similarly sized quantum dots and should facilitate
the development of Auger-recombination-free colloidal nanostructures for a
range of applications from lasers and light-emitting diodes to photodetectors
and solar cells.


title:
The influence of Auger recombination on the performance of quantum-dot
  light-emitting diodes

abstract:
  A growing interest in colloidal quantum dot (QD) based light-emitting diodes
(QD-LEDs) has been motivated by the exceptional color purity and spectral
tunability of QD emission as well as the amenability of QD materials to highly
scalable and inexpensive solution processing. One current challenge in the
QD-LED field has been a still incomplete understanding of the role of extrinsic
factors (e.g., recombination via QD surface defects) versus intrinsic processes
such as multicarrier Auger recombination or electron-hole separation due to
applied electric field in defining device efficiency. Here, we address this
problem with a study of excited-state dynamics in a series of structurally
engineered QDs, which is performed in parallel with characterization of their
performance upon incorporation into LEDs. The results of this study indicate
that under both zero and forward bias, a significant fraction of the QDs within
the active emitting layer is negatively charged and therefore, Auger
recombination represents an important factor limiting the efficiency of these
devices. We further observe that the onset of the LED efficiency roll-off is
also controlled by Auger recombination and can be shifted to higher currents by
using newly developed QDs with an intermediate alloy layer at the core-shell
interface introduced for suppression of Auger decay. Our findings suggest that
further improvement in the performance of QD-LEDs can be achieved by developing
effective approaches for controlling Auger recombination and/or minimizing the
effects of QD charging via improved balancing of electron and hole injection
currents.


title: Multi-solitons with vector mesons on the two-sphere

abstract:
  Recent studies have suggested a strong connection between the static
solutions of the 3D Skyrme model and those corresponding to its low-dimensional
analog (baby-Skyrme model) on a two-sphere. We have found almost identical
solutions considering an alternative two-dimensional model in which a vector
meson field is introduced and coupled to the system, instead of the usual
Skyrme term. It has been known that including this vector meson field in three
dimensions stabilizes the non-linear sigma model without the need of a term
quartic on derivatives of the pion fields (Skyrme term). In the present work,
we have numerically searched for static multi-solitonic solutions of this
alternative stabilization, for the case in which the base-space is a
two-sphere. Moreover, we analyze the stability of these solutions under small
perturbations in a fully dynamical setting. We have also considered the
inclusion of a particular potential term into the Lagrangian, and explored the
low/high-density phases of solitons for different ranges of the parameter
space, achieving solitons localized enough that allow us to compare with planar
(two-dimensional) studies.


title: Usage habits of business information system in Hungary

abstract:
  The IT functions of the companies can be executed in different ways inhouse
solution, outsourcing, in sourcing, formation a spinoff company. Predominantly
this function is provided within the company in Hungary. The larger a company
is; it is more likely that a separate IT manager will be entrusted for the
supervision of IT functions. Only a very small number of smallsized enterprises
said that they paid special attention to formulating an IT strategy, while it
was not considered important by microenterprises at all.


title:
On Minimizers of the Landau-de Gennes Energy Functional on Planar
  Domains

abstract:
  We study tensor-valued minimizers of the Landau-de Gennes energy functional
on a simply-connected planar domain $\Omega$ with non-contractible boundary
data. Here the tensorial field represents the second moment of a local
orientational distribution of rod-like molecules of a nematic liquid crystal.
Under the assumption that the energy depends on a single parameter---a
dimensionless elastic constant $\eps>0$---we establish that, as $\eps\to0$, the
minimizers converge to a projection-valued map that minimizes the Dirichlet
integral away from a single point in $\Omega$. We also provide a description of
the limiting map.


title: Superconductivity, diamagnetism, and the mean inner potential of solids

abstract:
  The mean inner potential of a solid is known to be proportional to its
diamagnetic susceptibility. Superconductors exhibit giant diamagnetism. What
does this say about the connection between superconductivity and mean inner
potential? Nothing, according to the conventional theory of superconductivity.
Instead, we propose that a deep connection exists between the mean inner
potential, diamagnetism, and superconductivity: that they are all intimately
linked to the fundamental charge asymmetry of matter. We discuss how this
physics can be probed experimentally and what the implications of different
experimental findings would be for the understanding of superconductivity.


title: The 500 simplest hyperbolic knots

abstract:
  We identify all hyperbolic knots whose complements are in the census of
orientable one-cusped hyperbolic manifolds with eight ideal tetrahedra. We also
compute their Jones polynomials.


title: Parameterized Complexity Results for Plan Reuse

abstract:
  Planning is a notoriously difficult computational problem of high worst-case
complexity. Researchers have been investing significant efforts to develop
heuristics or restrictions to make planning practically feasible. Case-based
planning is a heuristic approach where one tries to reuse previous experience
when solving similar problems in order to avoid some of the planning effort.
Plan reuse may offer an interesting alternative to plan generation in some
settings.
  We provide theoretical results that identify situations in which plan reuse
is provably tractable. We perform our analysis in the framework of
parameterized complexity, which supports a rigorous worst-case complexity
analysis that takes structural properties of the input into account in terms of
parameters. A central notion of parameterized complexity is fixed-parameter
tractability which extends the classical notion of polynomial-time tractability
by utilizing the effect of structural properties of the problem input.
  We draw a detailed map of the parameterized complexity landscape of several
variants of problems that arise in the context of case-based planning. In
particular, we consider the problem of reusing an existing plan, imposing
various restrictions in terms of parameters, such as the number of steps that
can be added to the existing plan to turn it into a solution of the planning
instance at hand.


title:
Time-reversal operation and transport phenomena in topological
  insulators

abstract:
  We prove that any forms of electric current measurements within a gapped or
gapless quantum system necessarily violate the time reversal symmetry (TRS). We
then use the ionization energy theory to unequivocally show that the metallic
surface states of a topological insulator consist of some special energy level
crossings, not due to TRS induced Kramers degeneracy because there is a finite
energy gap due to different wavefunctions. We use this special crossings and
derive the electron-ion scattering rate required to explain the resistivity and
carrier-type transition in (Bi1-xSbx)2Te3 and Pb1-xSnxSe topological
insulators.


title:
BV Minimizers of the area functional in the Heisenberg group under the
  bounded slope condition

abstract:
  We consider the area functional for t-graphs in the sub-Riemannian Heisenberg
group and study minimizers of the associated Dirichlet problem. We prove that,
under a bounded slope condition on the boundary datum, there exists a unique
minimizer and that this minimizer is Lipschitz continuous. We also provide an
example showing that, in the first Heisenberg group, Lipschitz regularity is
sharp even under the bounded slope condition.


title: Dissipative production of a maximally entangled steady state

abstract:
  Entangled states are a key resource in fundamental quantum physics, quantum
cryp-tography, and quantum computation [1].To date, controlled unitary
interactions applied to a quantum system, so-called "quantum gates", have been
the most widely used method to deterministically create entanglement [2]. These
processes require high-fidelity state preparation as well as minimizing the
decoherence that inevitably arises from coupling between the system and the
environment and imperfect control of the system parameters. Here, on the
contrary, we combine unitary processes with engineered dissipation to
deterministically produce and stabilize an approximate Bell state of two
trapped-ion qubits independent of their initial state. While previous works
along this line involved the application of sequences of multiple
time-dependent gates [3] or generated entanglement of atomic ensembles
dissipatively but relied on a measurement record for steady-state entanglement
[4], we implement the process in a continuous time-independent fashion,
analogous to optical pumping of atomic states. By continuously driving the
system towards steady-state, the entanglement is stabilized even in the
presence of experimental noise and decoherence. Our demonstration of an
entangled steady state of two qubits represents a step towards dissipative
state engineering, dissipative quantum computation, and dissipative phase
transitions [5-7]. Following this approach, engineered coupling to the
environment may be applied to a broad range of experimental systems to achieve
desired quantum dynamics or steady states. Indeed, concurrently with this work,
an entangled steady state of two superconducting qubits was demonstrated using
dissipation [8].


title:
Conjecture on the value of Pi(10^26), the number of primes less than
  10^26

abstract:
  Based on the first 25 known values of Pi(10^n), the number of primes less
than 10^n, with n integer between 1 and 25, we propose a conjectured value
range of Pi(10^26) calculated by using polynomial interpolations with two
corrective functions obtained by Thiele interpolations on relative differences
of exact and interpolated values of Pi(10^n). The conjectured range value is in
agreement with values obtained by the Eulerian logarithmic integral and with
the Riemann functions.


title:
The first confirmation of V-type asteroids among the Mars crosser
  population

abstract:
  The Mars crossing region constitutes a path to deliver asteroids from the
Inner Main Belt to the Earth crossing space. While both the Inner Main Belt and
the population of Earth crossing asteroids contains a significant fraction of
asteroids belonging to the V taxonomic class, only two of such V-type asteroids
has been detected in the Mars crossing region up to now. In this work, we
searched for asteroids belonging to the V class among the population of Mars
crossing asteroids, in order to support alternative paths to the delivery of
this bodies into the Earth crossing region. We selected 18 candidate V-type
asteroids in the Mars crossing region using observations contained in the Sloan
Digital Sky Survey Moving Objects Catalog. Then, we observed 4 of these
candidates to take their visible spectra using the Southern Astrophysical
Research Telescope (SOAR). We also performed the numerical simulation of the
orbital evolution of the observed asteroids. We confirmed that 3 of the
observed asteroids belong to the V class, and one of these may follow a path
that drives it to an Earth collision in some tens of million years.


title: Relativistic disks with two charged perfect fluids components

abstract:
  A method to describe exact solutions of the Einstein-Maxwell field equations
in terms of relativistic thin disks constituted by two perfect charged fluids
is presented. Describing the surface of the disk as a single charged fluid we
find explicit expressions for the rest energies, the pressures and the electric
charge densities of the two fluids. An explicit example is given. The
particular case of the thin disks composed by two charged perfect fluids with
barotropic equation of state is also presented.


title: Continuity of discrete homomorphisms of diffeomorphism groups

abstract:
  Let $M$ and $N$ be two closed $C^{\infty}$ manifolds and let
$\text{Diff}_c(M)$ denote the group of $C^{\infty}$ diffeomorphisms isotopic to
the identity. We prove that any (discrete) group homomorphism between
$\text{Diff}_c(M)$ and $\text{Diff}_c(N)$ is continuous. We also show that a
non-trivial group homomorphism $\Phi: \text{Diff}_c(M) \to \text{Diff}_c(N)$
implies that $\dim(M) \leq \dim(N)$ and give a classification of such
homomorphisms when $\dim(M) = \dim(N)$.


title:
f(R) in Holographic and Agegraphic Dark Energy Models and the
  Generalized Uncertainty Principle

abstract:
  We studied a unified approach with the holographic, new agegraphic and the
$f(R)$ dark energy model to construct the form of $f(R)$ which in general
responsible for the curvature driven explanation of the very early inflation
along with presently observed late time acceleration. We considered the
generalized uncertainty principle in our approach which incorporated the
corrections in the entropy area relation and thereby modified the energy
densities for the cosmological dark energy models considered. We found that
holographic and new agegraphic $f(R)$ gravity models can behave like phantom or
quintessence models in the spatially flat FRW universe. We also found a
distinct term in the form of $f(R)$ which goes as $R^{\frac{3}{2}}$ due to the
consideration of the GUP modified energy densities. Although the presence of
this term in the action can have its importance in explaining the early
inflationary scenario but Capozziello {\it et.al.} recently showed that $f(R)
\sim R^{\frac{3}{2}}$ leads to an accelerated expansion, {\it i.e.}, a negative
value for the deceleration parameter $q$ which fit well with SNeIa and WMAP
data.


title: Polynomial Supersymmetry for Matrix Hamiltonians

abstract:
  We study intertwining relations for matrix one-dimensional, in general,
non-Hermitian Hamiltonians by matrix differential operators of arbitrary order.
It is established that for any matrix intertwining operator Q_N^- of minimal
order N there is a matrix operator Q_{N'}^+ of different, in general, order N'
that intertwines the same Hamiltonians as Q_N^- in the opposite direction and
such that the products Q_{N'}^+Q_N^- and Q_N^-Q_{N'}^+ are identical
polynomials of the corresponding Hamiltonians. The related polynomial algebra
of supersymmetry is constructed. The problems of minimization and of
reducibility of a matrix intertwining operator are considered and the criteria
of minimizability and of reducibility are presented. It is shown that there are
absolutely irreducible matrix intertwining operators, in contrast to the scalar
case.


title: Non-equilibrium Phase Transitions: Activated Random Walks at Criticality

abstract:
  In this paper we present rigorous results on the critical behavior of the
Activated Random Walk model. We conjecture that on a general class of graphs,
including $\mathbb{Z}^d$, and under general initial conditions, the system at
the critical point does not reach an absorbing state. We prove this for the
case where the sleep rate $\lambda$ is infinite. Moreover, for the
one-dimensional asymmetric system, we identify the scaling limit of the flow
through the origin at criticality. The case $\lambda < + \infty$ remains
largely open, with the exception of the one-dimensional totally-asymmetric
case, for which it is known that there is no fixation at criticality.

categories: math.PR cond-mat.stat-mech math-ph math.MP


title: Symmetron Inflation

abstract:
  We define a new inflationary scenario in which inflation starts naturally
after the Big Bang when the energy density drops below some critical value. As
a model, we use recently proposed symmetron field whose effective potential
depends on the energy density of the environment. At high densities, right
after the Big Bang, the potential for the symmetron is trivial, and the field
sits in equilibrium at the bottom of the potential. When the density drops
below some critical value, the potential changes its shape into a symmetry
breaking potential, and the field starts rolling down. This scenario does not
require any special initial conditions for inflation to start. We also
construct a concrete model with two fields, i.e. with symmetron as an inflaton
and an additional scalar field which describes the matter content in the early
universe. For the simplest coupling, the amplitude and shape of the power
spectrum are the same as in the single field slow-roll inflation.


title: Differential Invariants for the Korteweg-de Vries Equation

abstract:
  Differential invariants for the maximal Lie invariance group of the
Korteweg-de Vries equation are computed using the moving frame method and
compared with existing results. Closed forms of differential invariants of any
order are presented for two sets of normalization conditions. Minimal bases of
differential invariants associated with the chosen normalization conditions are
given.


title:
Confirmation of the exclusive association between 6.7-GHz methanol
  masers and high-mass star formation regions

abstract:
  Recently, a comparison between the locations of 6.7-GHz methanol masers and
dust continuum emission has renewed speculation that these masers can be
associated with evolved stars. The implication of such a scenario would be
profound, especially for the interpretation of large surveys for 6.7-GHz
masers, individual studies where high-mass star formation has been inferred
from the presence of 6.7-GHz methanol masers, and for the pumping mechanisms of
these masers. We have investigated the two instances where 6.7-GHz methanol
masers have been explicitly suggested to be associated with evolved stars, and
we find the first to be associated with a standard high-mass star formation
region, and the second to be a spurious detection. We also find no evidence to
suggest that the methanol maser action can be supported in the environments of
evolved stars. We thereby confirm their exclusive association with high-mass
star formation regions.


title: Glassy dynamics in three-dimensional embryonic tissues

abstract:
  Many biological tissues are viscoelastic, behaving as elastic solids on short
timescales and fluids on long timescales. This collective mechanical behavior
enables and helps to guide pattern formation and tissue layering. Here we
investigate the mechanical properties of three-dimensional tissue explants from
zebrafish embryos by analyzing individual cell tracks and macroscopic
mechanical response. We find that the cell dynamics inside the tissue exhibit
features of supercooled fluids, including subdiffusive trajectories and
signatures of caging behavior. We develop a minimal, three-parameter mechanical
model for these dynamics, which we calibrate using only information about cell
tracks. This model generates predictions about the macroscopic bulk response of
the tissue (with no fit parameters) that are verified experimentally, providing
a strong validation of the model. The best-fit model parameters indicate that
although the tissue is fluid-like, it is close to a glass transition,
suggesting that small changes to single-cell parameters could generate a
significant change in the viscoelastic properties of the tissue. These results
provide a robust framework for quantifying and modeling mechanically-driven
pattern formation in tissues.


title: Forecasting neutron star temperatures: predictability and variability

abstract:
  It is now possible to model thermal relaxation of neutron stars after bouts
of accretion during which the star is heated out of equilibrium by nuclear
reactions in its crust. Major uncertainties in these models can be encapsulated
in modest variations of a handful of fudge parameters that change the crustal
thermal conductivity, specific heat, and heating rates. Observations of thermal
relaxation constrain these fudge parameters and allow us to predict longer term
variability in terms of the neutron star core temperature. We demonstrate this
explicitly by modeling ongoing thermal relaxation in the neutron star XTE
J1701-462. Its future cooling, over the next 5 to 30 years, is strongly
constrained and depends mostly on its core temperature, uncertainties in crust
physics having essentially been pinned down by fitting to the first three years
of observations.


title: The degree-diameter problem for sparse graph classes

abstract:
  The degree-diameter problem asks for the maximum number of vertices in a
graph with maximum degree $\Delta$ and diameter $k$. For fixed $k$, the answer
is $\Theta(\Delta^k)$. We consider the degree-diameter problem for particular
classes of sparse graphs, and establish the following results. For graphs of
bounded average degree the answer is $\Theta(\Delta^{k-1})$, and for graphs of
bounded arboricity the answer is $\Theta(\Delta^{\floor{k/2}})$, in both cases
for fixed $k$. For graphs of given treewidth, we determine the the maximum
number of vertices up to a constant factor. More precise bounds are given for
graphs of given treewidth, graphs embeddable on a given surface, and
apex-minor-free graphs.


title:
A Stochastic Successive Minimization Method for Nonsmooth Nonconvex
  Optimization with Applications to Transceiver Design in Wireless
  Communication Networks

abstract:
  Consider the problem of minimizing the expected value of a cost function
parameterized by a random variable. The classical sample average approximation
(SAA) method for solving this problem requires minimization of an ensemble
average of the objective at each step, which can be expensive. In this paper,
we propose a stochastic successive upper-bound minimization method (SSUM) which
minimizes an approximate ensemble average at each iteration. To ensure
convergence and to facilitate computation, we require the approximate ensemble
average to be a locally tight upper-bound of the expected cost function and be
easily optimized. The main contributions of this work include the development
and analysis of the SSUM method as well as its applications in linear
transceiver design for wireless communication networks and online dictionary
learning. Moreover, using the SSUM framework, we extend the classical
stochastic (sub-)gradient (SG) method to the case of minimizing a nonsmooth
nonconvex objective function and establish its convergence.


title: Locally $C^*$ Algebras, $C^*$ Bundles and Noncommutative Spaces

abstract:
  This work provides a generalization of the Gelfand duality to the context of
noncommutative locally $C^*$ algebras. Using a reformulation of a theorem
proven by Dauns and Hofmann in the 60's we show that every locally $C^*$
algebra can be realized as the algebra of continuous sections of a $C^*$ bundle
over a compactly generated topological space. This result is used then to show
that on certain special cases locally $C^*$ algebras can be used to define
certain sheaves of locally $C^*$ algebras that, inspired by the analogy with
commutative geometry, we call noncommutative spaces. The last section provides
some examples, motivated by mathematical physics, for this definition of
noncommutative space. Namely we show that every local net of $C^*$ algebras
defines a noncommutative space and, based on a loose generalization of the
original construction by Doplicher, Fredenhagen and Roberts, construct what we
propose to call a "locally covariant quantum spacetime".


title:
CP and CPT Violating Parameters Determined from the Joint Decays of
  $C=+1$ Entangled Neutral Pseudoscalar Mesons

abstract:
  Entangled pseudoscalar neutral meson pairs have been used in studying CP
violation and searching CPT violation, but almost all the previous works
concern $C=-1$ entangled state. Here we consider $C=+1$ entangled state of
pseudoscalar neutral mesons, which is quite different from $C=-1$ entangled
state and provides complementary information on symmetry violating parameters.
After developing a general formalism, we consider three kinds of decay
processes, namely, semileptonic-semileptonic, hadronic-hadronic and
semileptonic-hadronic processes. For each kind of processes, we calculate the
integrated rates of joint decays with a fixed time interval, as well as
asymmetries defined for these joint rates of different channels. In turn, these
asymmetries can be used to determine the four real numbers of the two indirect
symmetry violating parameters, based on a general relation between the symmetry
violating parameters and the decay asymmetries presented here. Various
discussions are made on indirect and direct violations and the violation of
$\Delta {\cal F} =\Delta Q$ rule, with some results presented as theorems.


title: Einstein's random walk and thermal diffusion

abstract:
  Thermal diffusion has been studied for over 150 years. Despite of the long
history and the increasing importance of the phenomenon, the physics of thermal
diffusion remains poorly understood. In this paper Ludwig's thermal diffusion
is explained using Einstein's random walk. The only new structure added is the
spatial heterogeneity of the random walk to reflect the temperature gradient of
thermal diffusion. Hence, the walk length and the walk speed are location
dependent functions in this paper. Then, a mathematical understanding of such a
random walk gives the foundation of the thermal diffusion as clearly as the
original homogeneous case of Einstein.


title: Microwave quantum logic spectroscopy and control of molecular ions

abstract:
  A general method for rotational microwave spectroscopy and control of polar
molecular ions via direct microwave addressing is considered. Our method makes
use of spatially varying AC Stark shifts, induced by far off-resonant, focused
laser beams to achieve an effective coupling between the rotational state of a
molecular ion and the electronic state of an atomic ion. In this setting, the
atomic ion is used for read-out of the molecular ion state, in a manner
analogous to quantum logic spectroscopy based on Raman transitions. In addition
to high-precision spectroscopy, this setting allows for rotational ground state
cooling, and can be considered as a candidate for the quantum information
processing with polar molecular ions. All elements of our proposal can be
realized with currently available technology.


title:
An Outage Exponent Region based Coded f-Matching Framework for Channel
  Allocation in Multi-carrier Multi-access Channels

abstract:
  The multi-carrier multi-access technique is widely adopt in future wireless
communication systems, such as IEEE 802.16m and 3GPP LTE-A. The channel
resources allocation in multi-carrier multi-access channel, which can greatly
improve the system throughput with QoS assurance, thus attracted much attention
from both academia and industry. There lacks, however, an analytic framework
with a comprehensive performance metric, such that it is difficult to fully
exploit the potentials of channel allocation. This paper will propose an
analytic coded fmatching framework, where the outage exponent region (OER) will
be defined as the performance metric. The OER determines the relationship of
the outage performance among all of the users in the full SNR range, and
converges to the diversity-multiplexing region (DMR) when SNR tends to
infinity. To achieve the optimal OER and DMR, the random bipartite graph (RBG)
approach, only depending on 1 bit CSI, will be proposed to formulate this
problem. Based on the RBG formulation, the optimal frequency-domain coding
based maximum f-matching method is then proposed. By analyzing the
combinatorial structure of the RBG based coded f-matching with the help of
saddlepoint approximation, the outage probability of each user, OER, and DMR
will be derived in closed-form formulas. It will be shown that all of the users
share the total multiplexing gain according to their rate requirements, while
achieving the full frequency diversity, i.e., the optimal OER and DMR. Based on
the principle of parallel computations, the parallel vertices expansion &
random rotation based Hopcroft-Karp (PVER2HK) algorithm, which enjoys a
logarithmic polynomial complexity, will be proposed. The simulation results
will not only verify the theoretical derivations, but also show the significant
performance gains.


title:
Distributed Raptor Coding for Erasure Channels: Partially and Fully
  Coded Cooperation

abstract:
  In this paper, we propose a new rateless coded cooperation scheme for a
general multi-user cooperative wireless system. We develop cooperation methods
based on Raptor codes with the assumption that the channels face erasure with
specific erasure probabilities and transmitters have no channel state
information. A fully coded cooperation (FCC) and a partially coded cooperation
(PCC) strategy are developed to maximize the average system throughput. Both
PCC and FCC schemes have been analyzed through AND-OR tree analysis and a
linear programming optimization problem is then formulated to find the optimum
degree distribution for each scheme. Simulation results show that optimized
degree distributions can bring considerable throughput gains compared to
existing degree distributions which are designed for point-to-point binary
erasure channels. It is also shown that the PCC scheme outperforms the FCC
scheme in terms of average system throughput.


title: Boundaries in the Moyal plane

abstract:
  We study the oscillations of a scalar field on a noncommutative disc
implementing the boundary as the limit case of an interaction with an
appropriately chosen confining background. The space of quantum fluctuations of
the field is finite dimensional and displays the rotational and parity symmetry
of the disc. We perform a numerical evaluation of the (finite) Casimir energy
and obtain similar results as for the fuzzy sphere and torus.


title:
Zielonka's Recursive Algorithm: dull, weak and solitaire games and
  tighter bounds

abstract:
  Dull, weak and nested solitaire games are important classes of parity games,
capturing, among others, alternation-free mu-calculus and ECTL* model checking
problems. These classes can be solved in polynomial time using dedicated
algorithms. We investigate the complexity of Zielonka's Recursive algorithm for
solving these special games, showing that the algorithm runs in O(d (n + m)) on
weak games, and, somewhat surprisingly, that it requires exponential time to
solve dull games and (nested) solitaire games. For the latter classes, we
provide a family of games G, allowing us to establish a lower bound of 2^(n/3).
We show that an optimisation of Zielonka's algorithm permits solving games from
all three classes in polynomial time. Moreover, we show that there is a family
of (non-special) games M that permits us to establish a lower bound of 2^(n/3),
improving on the previous lower bound for the algorithm.


title: The Rabin index of parity games

abstract:
  We study the descriptive complexity of parity games by taking into account
the coloring of their game graphs whilst ignoring their ownership structure.
Colored game graphs are identified if they determine the same winning regions
and strategies, for all ownership structures of nodes. The Rabin index of a
parity game is the minimum of the maximal color taken over all equivalent
coloring functions. We show that deciding whether the Rabin index is at least k
is in PTIME for k=1 but NP-hard for all fixed k > 1. We present an EXPTIME
algorithm that computes the Rabin index by simplifying its input coloring
function. When replacing simple cycle with cycle detection in that algorithm,
its output over-approximates the Rabin index in polynomial time. Experimental
results show that this approximation yields good values in practice.


title:
The stellar metallicity distribution of the Milky Way from the BATC
  survey

abstract:
  Using the stellar atmospheric parameters such as effective temperature and
metallicity derived from SDSS spectra for 2200 main sequence (MS) stars which
were also observed by Beijing - Arizona - Taiwan - Connecticut (BATC)
photometric system, we develop the polynomial photometric calibration method to
evaluate the stellar effective temperature and metallicity for BATC multi-color
photometric data. This calibration method has been applied to about 160 000 MS
stars from 67 BATC observed fields. Those stars have colors and magnitudes in
the ranges 0.1 < d - h < 1.4 and 14.0 < d < 21.0. We find that there is a peak
of metallicity distribution at [Fe/H] ~ -1.5 in the distance from the Galactic
plane |Z| > 5 kpc which corresponds to the halo component and a peak at [Fe/H]
~ -0.7 in the region 2 < |Z| < 5 kpc where is dominated by the thick disk
stars. The mean stellar metallicity smoothly decreases from -0.65 to -0.78 in
the interval 0.5 < |Z|< 2 kpc. Metallicity distributions in the halo and the
thick disk seem invariant with the distance from the Galactic plane.


title: A Faster Tableau for CTL*

abstract:
  There have been several recent suggestions for tableau systems for deciding
satisfiability in the practically important branching time temporal logic known
as CTL*. In this paper we present a streamlined and more traditional tableau
approach built upon the author's earlier theoretical work.
  Soundness and completeness results are proved. A prototype implementation
demonstrates the significantly improved performance of the new approach on a
range of test formulas. We also see that it compares favourably to state of the
art, game and automata based decision procedures.


title: Deciding the Satisfiability of MITL Specifications

abstract:
  In this paper we present a satisfiability-preserving reduction from MITL
interpreted over finitely-variable continuous behaviors to Constraint LTL over
clocks, a variant of CLTL that is decidable, and for which an SMT-based bounded
satisfiability checker is available. The result is a new complete and effective
decision procedure for MITL. Although decision procedures for MITL already
exist, the automata-based techniques they employ appear to be very difficult to
realize in practice, and, to the best of our knowledge, no implementation
currently exists for them. A prototype tool for MITL based on the encoding
presented here has, instead, been implemented and is publicly available.


title: Improving HyLTL model checking of hybrid systems

abstract:
  The problem of model-checking hybrid systems is a long-time challenge in the
scientific community. Most of the existing approaches and tools are either
limited on the properties that they can verify, or restricted to simplified
classes of systems. To overcome those limitations, a temporal logic called
HyLTL has been recently proposed. The model checking problem for this logic has
been solved by translating the formula into an equivalent hybrid automaton,
that can be analized using existing tools. The original construction employs a
declarative procedure that generates exponentially many states upfront, and can
be very inefficient when complex formulas are involved. In this paper we solve
a technical issue in the construction that was not considered in previous
works, and propose a new algorithm to translate HyLTL into hybrid automata,
that exploits optimized techniques coming from the discrete LTL community to
build smaller automata.


title:
Profile Trees for B\"uchi Word Automata, with Application to
  Determinization

abstract:
  The determinization of Buchi automata is a celebrated problem, with
applications in synthesis, probabilistic verification, and multi-agent systems.
Since the 1960s, there has been a steady progress of constructions: by
McNaughton, Safra, Piterman, Schewe, and others. Despite the proliferation of
solutions, they are all essentially ad-hoc constructions, with little theory
behind them other than proofs of correctness. Since Safra, all optimal
constructions employ trees as states of the deterministic automaton, and
transitions between states are defined operationally over these trees. The
operational nature of these constructions complicates understanding,
implementing, and reasoning about them, and should be contrasted with
complementation, where a solid theory in terms of automata run DAGs underlies
modern constructions.
  In 2010, we described a profile-based approach to Buchi complementation,
where a profile is simply the history of visits to accepting states. We
developed a structural theory of profiles and used it to describe a
complementation construction that is deterministic in the limit. Here we extend
the theory of profiles to prove that every run DAG contains a profile tree with
at most a finite number of infinite branches. We then show that this property
provides a theoretical grounding for a new determinization construction where
macrostates are doubly preordered sets of states. In contrast to extant
determinization constructions, transitions in the new construction are
described declaratively rather than operationally.


title: Weighted Automata and Monadic Second Order Logic

abstract:
  Let S be a commutative semiring. M. Droste and P. Gastin have introduced in
2005 weighted monadic second order logic WMSOL with weights in S. They use a
syntactic fragment RMSOL of WMSOL to characterize word functions (power series)
recognizable by weighted automata, where the semantics of quantifiers is used
both as arithmetical operations and, in the boolean case, as quantification.
  Already in 2001, B. Courcelle, J.Makowsky and U. Rotics have introduced a
formalism for graph parameters definable in Monadic Second order Logic, here
called MSOLEVAL with values in a ring R. Their framework can be easily adapted
to semirings S. This formalism clearly separates the logical part from the
arithmetical part and also applies to word functions.
  In this paper we give two proofs that RMSOL and MSOLEVAL with values in S
have the same expressive power over words. One proof shows directly that
MSOLEVAL captures the functions recognizable by weighted automata. The other
proof shows how to translate the formalisms from one into the other.


title: Approximating the minimum cycle mean

abstract:
  We consider directed graphs where each edge is labeled with an integer weight
and study the fundamental algorithmic question of computing the value of a
cycle with minimum mean weight. Our contributions are twofold: (1) First we
show that the algorithmic question is reducible in O(n^2) time to the problem
of a logarithmic number of min-plus matrix multiplications of n-by-n matrices,
where n is the number of vertices of the graph. (2) Second, when the weights
are nonnegative, we present the first (1 + {\epsilon})-approximation algorithm
for the problem and the running time of our algorithm is \tilde(O)(n^\omega
log^3(nW/{\epsilon}) / {\epsilon}), where O(n^\omega) is the time required for
the classic n-by-n matrix multiplication and W is the maximum value of the
weights.


title: Probabilistic data flow analysis: a linear equational approach

abstract:
  Speculative optimisation relies on the estimation of the probabilities that
certain properties of the control flow are fulfilled. Concrete or estimated
branch probabilities can be used for searching and constructing advantageous
speculative and bookkeeping transformations.
  We present a probabilistic extension of the classical equational approach to
data-flow analysis that can be used to this purpose. More precisely, we show
how the probabilistic information introduced in a control flow graph by branch
prediction can be used to extract a system of linear equations from a program
and present a method for calculating correct (numerical) solutions.


title: Slot Games for Detecting Timing Leaks of Programs

abstract:
  In this paper we describe a method for verifying secure information flow of
programs, where apart from direct and indirect flows a secret information can
be leaked through covert timing channels. That is, no two computations of a
program that differ only on high-security inputs can be distinguished by
low-security outputs and timing differences. We attack this problem by using
slot-game semantics for a quantitative analysis of programs. We show how
slot-games model can be used for performing a precise security analysis of
programs, that takes into account both extensional and intensional properties
of programs. The practicality of this approach for automated verification is
also shown.


title: Alternating-time temporal logic with finite-memory strategies

abstract:
  Model-checking the alternating-time temporal logics ATL and ATL* with
incomplete information is undecidable for perfect recall semantics. However,
when restricting to memoryless strategies the model-checking problem becomes
decidable. In this paper we consider two other types of semantics based on
finite-memory strategies. One where the memory size allowed is bounded and one
where the memory size is unbounded (but must be finite). This is motivated by
the high complexity of model-checking with perfect recall semantics and the
severe limitations of memoryless strategies. We show that both types of
semantics introduced are different from perfect recall and memoryless semantics
and next focus on the decidability and complexity of model-checking in both
complete and incomplete information games for ATL/ATL*. In particular, we show
that the complexity of model-checking with bounded-memory semantics is
Delta_2p-complete for ATL and PSPACE-complete for ATL* in incomplete
information games just as in the memoryless case. We also present a proof that
ATL and ATL* model-checking is undecidable for n >= 3 players with
finite-memory semantics in incomplete information games.


title: Modularity and Openness in Modeling Multi-Agent Systems

abstract:
  We revisit the formalism of modular interpreted systems (MIS) which
encourages modular and open modeling of synchronous multi-agent systems. The
original formulation of MIS did not live entirely up to its promise. In this
paper, we propose how to improve modularity and openness of MIS by changing the
structure of interference functions. These relatively small changes allow for
surprisingly high flexibility when modeling actual multi-agent systems. We
demonstrate this on two well-known examples, namely the trains, tunnel and
controller, and the dining cryptographers.
  Perhaps more importantly, we propose how the notions of multi-agency and
openness, crucial for multi-agent systems, can be precisely defined based on
their MIS representations.


title: Satisfiability of ATL with strategy contexts

abstract:
  Various extensions of the temporal logic ATL have recently been introduced to
express rich properties of multi-agent systems. Among these, ATLsc extends ATL
with strategy contexts, while Strategy Logic has first-order quantification
over strategies. There is a price to pay for the rich expressiveness of these
logics: model-checking is non-elementary, and satisfiability is undecidable.
  We prove in this paper that satisfiability is decidable in several special
cases. The most important one is when restricting to turn-based games. We prove
that decidability also holds for concurrent games if the number of moves
available to the agents is bounded. Finally, we prove that restricting strategy
quantification to memoryless strategies brings back undecidability.


title: Model checking coalitional games in shortage resource scenarios

abstract:
  Verification of multi-agents systems (MAS) has been recently studied taking
into account the need of expressing resource bounds. Several logics for
specifying properties of MAS have been presented in quite a variety of
scenarios with bounded resources. In this paper, we study a different
formalism, called Priced Resource-Bounded Alternating-time Temporal Logic
(PRBATL), whose main novelty consists in moving the notion of resources from a
syntactic level (part of the formula) to a semantic one (part of the model).
This allows us to track the evolution of the resource availability along the
computations and provides us with a formalisms capable to model a number of
real-world scenarios. Two relevant aspects are the notion of global
availability of the resources on the market, that are shared by the agents, and
the notion of price of resources, depending on their availability. In a
previous work of ours, an initial step towards this new formalism was
introduced, along with an EXPTIME algorithm for the model checking problem. In
this paper we better analyze the features of the proposed formalism, also in
comparison with previous approaches. The main technical contribution is the
proof of the EXPTIME-hardness of the the model checking problem for PRBATL,
based on a reduction from the acceptance problem for Linearly-Bounded
Alternating Turing Machines. In particular, since the problem has multiple
parameters, we show two fixed-parameter reductions.


title:
s-Numbers of compact embeddings of function spaces on quasi-bounded
  domains

abstract:
  We prove asymptotic formulas for the behavior of approximation, Gelfand,
Kolmogorov and Weyl numbers of Sobolev embeddings between Besov and
Triebel-Lizorkin spaces defined on quasi-bounded domains.


title: On the sbottom resonance in dark matter scattering

abstract:
  A resonance in the neutralino-nucleus elastic scattering cross section is
usually purported when the neutralino-sbottom mass difference m_sbottom-m_chi
is equal to the bottom quark mass m_b ~ 4 GeV. Such a scenario has been
discussed as a viable model for light (~ 10 GeV) neutralino dark matter as
explanation of possible DAMA and CoGeNT direct detection signals. Here we give
physical and analytical arguments showing that the sbottom resonance may
actually not be there. In particular, we show analytically that the one-loop
gluon-neutralino scattering amplitude has no pole at m_sbottom=m_chi+m_b, while
by analytic continuation to the regime m_sbottom<m_chi, it develops a pole at
m_sbottom=m_chi-m_b. In the limit of vanishing gluon momenta, this pole
corresponds to the only cut of the neutralino self-energy diagram with a quark
and a squark running in the loop, when the decay process chi->squark+quark
becomes kinematically allowed. The pole can be interpreted as the formation of
a sbottom-antibottom-qqq or antisbottom-bottom qqq resonant state (where qqq
are the nucleon valence quarks), which is kinematically not accessible if the
neutralino is the LSP. Our analysis shows that the common practice of
estimating the neutralino-nucleon cross section by introducing an ad-hoc pole
at m_sbottom=m_chi+m_b into the effective four-fermion interaction (including
higher-twist effects) should be discouraged, since it corresponds to adding a
spurious pole to the scattering process at the center-of-mass energy sqrt(s)
m_chi m_sbottom-m_b. Our considerations can be extended from the specific case
of supersymmetry to other cases in which the dark matter particle scatters off
nucleons through the exchange of a b-flavored state almost degenerate to its
mass, such as in theories with extra dimensions and in other mass-degenerate
dark matter scenarios recently discussed in the literature.


title:
Functional inequalities on path space over a non-compact Riemannian
  manifold

abstract:
  We prove the existence of the O-U Dirichlet form and the damped O-U Dirichlet
form on path space over a general non-compact Riemannian manifold which is
complete and stochastically complete. We show a weighted log-Sobolev inequality
for the O-U Dirichlet form and the (standard) log-Sobolev inequality for the
damped O-U Dirichlet form. In particular, the Poincar\'e inequality (and the
super Poincar\'e inequality) can be established for the O-U Dirichlet form on
path space over a class of Riemannian manifolds with unbounded Ricci
curvatures. Moreover, we construct a large class of quasi-regular local
Dirichlet forms with unbounded random diffusion coefficients on the path space
over a general non-compact manifold.


title:
Critical exponent for the Anderson transition in the three dimensional
  orthogonal universality class

abstract:
  We report a careful finite size scaling study of the metal insulator
transition in Anderson's model of localisation. We focus on the estimation of
the critical exponent $\nu$ that describes the divergence of the localisation
length. We verify the universality of this critical exponent for three
different distributions of the random potential: box, normal and Cauchy. Our
results for the critical exponent are consistent with the measured values
obtained in experiments on the dynamical localisation transition in the quantum
kicked rotor realised in a cold atomic gas.


title:
Interstellar gas towards CTB 37A and the TeV gamma-ray source HESS
  J1714-385

abstract:
  Observations of dense molecular gas towards the supernova remnants CTB 37A
(G348.5+0.1) and G348.5-0.0 were carried out using the Mopra and Nanten2 radio
telescopes. We present CO(2-1) and CS(1-0) emission maps of a region
encompassing the CTB 37A TeV gamma-ray emission, HESS J1714-385, revealing
regions of dense gas within associated molecular clouds. Some gas displays good
overlap with gamma-ray emission, consistent with hadronic gamma-ray emission
scenarios. Masses of gas towards the HESS J1714-385 TeV gamma-ray emission
region were estimated, and were of the order of 10^3-10^4 solar masses. In the
case of a purely hadronic origin for the gamma-ray emission, the cosmic ray
flux enhancement is ~80-1100 times the local solar value. This enhancement
factor and other considerations allow a discussion of the age of CTB 37A, which
is consistent with ~10^4 yr.


title: A dynamical mechanism for generating quark confinement

abstract:
  We explore the dynamical mechanism for generating the infrared singular
quark-gluon vertex and quark confinement based on the gauge invariance in
covariant-gauge quantum chromodynamics(QCD). We first derive the
gauge-invariance constraint relation for the infrared-limit behavior of the
quark-gluon vertex, which shows the mechanism for generating the infrared
behavior of the quark-gluon vertex. We hence unravel a novel mechanism for
generating an infrared singular quark-gluon vertex and then a linear rising
potential for confining massive quarks, where the infrared singularity in the
form factors composing the quark-ghost scattering kernel plays a crucial role.
The mechanism for linking chiral symmetry breaking with quark confinement is
also shown.


title:
High Precision Differential Abundance Measurements in Globular Clusters:
  Chemical Inhomogeneities in NGC 6752

abstract:
  We report on a strictly differential line-by-line analysis of high quality
UVES spectra of bright giants in the metal-poor globular cluster NGC 6752. We
achieved high precision differential chemical abundance measurements for Fe,
Na, Si, Ca, Ti, Cr, Ni, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy with
uncertainties as low as ~0.01 dex (~2%). We obtained the following main
results. (1) The observed abundance dispersions are a factor of ~2 larger than
the average measurement uncertainty. (2) There are positive correlations, of
high statistical significance, between all elements and Na. (3) For any pair of
elements, there are positive correlations of high statistical significance,
although the amplitudes of the abundance variations are small. Removing
abundance trends with effective temperature and/or using a different pair of
reference stars does not alter these results. These abundance variations and
correlations may reflect a combination of (a) He abundance variations and (b)
inhomogeneous chemical evolution in the pre- or proto-cluster environment.
Regarding the former, the current constraints on Delta Y from photometry likely
preclude He as being the sole explanation. Regarding the latter, the
nucleosynthetic source(s) must have synthesised Na, alpha, Fe-peak and
neutron-capture elements and in constant amounts for species heavier than Si;
no individual object can achieve such nucleosynthesis. We speculate that other,
if not all, globular clusters may exhibit comparable abundance variations and
correlations to NGC 6752 if subjected to a similarly precise analysis.


title:
Testing the Mutually Enhanced Magicity Effect in Nuclear
  Incompressibility via the Giant Monopole Resonance in the $^{204,206,208}$Pb
  Isotopes

abstract:
  Using inelastic $\alpha$-scattering at extremely forward angles, including
$0^\circ$, the strength distributions of the isoscalar giant monopole resonance
(ISGMR) have been measured in the $^{204,206,208}$Pb isotopes in order to
examine the proposed mutually enhanced magicity (MEM) effect on the nuclear
incompressibility. The MEM effect had been suggested as a likely explanation of
the "softness" of nuclear incompressibility observed in the ISGMR measurements
in the Sn and Cd isotopes. Our experimental results rule out any manifestation
of the MEM effect in nuclear incompressibility and leave the question of the
softness of the open-shell nuclei unresolved still.


title: Enriched model categories in equivariant contexts

abstract:
  We give a general framework of equivariant model category theory. Our groups
G, called Hopf groups, are suitably defined group objects in any well-behaved
symmetric monoidal category V. For any V, a discrete group G gives a Hopf
group, denoted I[G]. When V is cartesian monoidal, the Hopf groups are just the
group objects in V. When V is the category of modules over a commutative ring
R, I[G] is the group ring R[G] and the general Hopf groups are the
cocommutative Hopf algebras over R. We show how all of the usual constructs of
equivariant homotopy theory, both categorical and model theoretic, generalize
to Hopf groups for any V. This opens up some quite elementary unexplored
mathematical territory, while systematizing more familiar terrain.


title:
Coronal-Temperature-Diagnostic Capability of the Hinode/X-Ray Telescope
  Based on Self-Consistent Calibration. II. Calibration with on-Orbit Data

abstract:
  The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray imager
that observes the solar corona with the capability of diagnosing coronal
temperatures from less than 1 MK to more than 10 MK. To make full use of this
capability, Narukage et al. (Solar Phys. 269, 169, 2011) determined the
thickness of each of the X-ray focal-plane analysis filters based on
calibration measurements from the ground-based end-to-end test. However, in
their paper, the calibration of the thicker filters for observations of active
regions and flares, namely the med-Be, med-Al, thick-Al and thick-Be filters,
was insufficient due to the insufficient X-ray flux used in the measurements.
In this work, we recalibrate those thicker filters using quiescent active
region data taken with multiple filters of XRT. On the basis of our updated
calibration results, we present the revised coronal-temperature-diagnostic
capability of XRT.


title:
Thermalized Non-Equilibrated Matter against Random Matrix Theory,
  Quantum Chaos and Direct Interaction: Warming up

abstract:
  The idea of a thermalized non-equilibrated state of matter offers a
conceptually new understanding of the strong angular asymmetry. In this compact
review we present some clarifications, corrections and further developments of
the approach, and provide a brief account of results previously discussed but
not reported in the literature. The cross symmetry compound nucleus $S$-matrix
correlations are obtained (i) starting from the unitary $S$-matrix
representation, (ii) by explicitly taking into account a process of energy
equilibration, and (iii) without taking the thermodynamic limit of an infinite
number of particles in the thermalized system. It is conjectured that the long
phase memory is due to the exponentially small total spin off-diagonal
resonance intensity correlations. This manifestly implies that the strong
angular asymmetry intimately relates to extremely small deviations of the
eigenfunction distribution from Gaussian law. The spin diagonal resonance
intensity correlations determine a new time/energy scale for a validity of
random matrix theory. Its definition does not involve overlaps of the many-body
interacting configurations with shell model non-interacting states and thus is
conceptually different from the physical meaning (inverse energy relaxation
time) of the spreading widths introduced by Wigner. Exact Gaussian distribution
of the resonance wave functions corresponds to the instantaneous phase
relaxation. We invite the nuclear reaction community for the competition to
describe, as the first challenge, the strong forward peaking in the typically
evaporation part of the proton spectra. This is necessary to initiate revealing
long-term misconduct in the heavily cross-disciplinary field, also important
for nuclear industry applications.


title:
First-principles study of electronic structure of
  $Bi_2Sr_2Ca_2Cu_3O_{10}$

abstract:
  We present for the first time the band structure calculation of
$Bi_2Sr_2Ca_2Cu_3O_{10}$ compound in the tetragonal structure (space group
$I4/mmm$). We used the Local Density Approximation (LDA) as in the Wien2k code.
We analyze in detail the band structure and the Fermi surface (FS). Our results
are in very good agreement with recent experiments. The FS shows the feature
known as the Bi-O pocket problem which we associate with the interaction of the
O3 atoms with the Cu2-O2 and Bi-O4 planes. Ceramic $Bi_2Sr_2Ca_2Cu_3O_{10}$
stabilized with Pb has been reported as a superconductor with $T_c \sim 100$.
CdS microparticles were embedded into the ceramic $Bi_2Sr_2Ca_2Cu_3O_{10}$. The
composite did show a superconducting phase transition at a lower $T_c \sim 70
K$. At even lower temperatures re-entrant behavior was observed. The sample
regain the superconducting state at $\sim 47 K$ [arXiv:1101.0277
[cond-mat.supr-con]]. This effect is not observe in the ceramic alone. This
calculation is useful per ser and also can contribute to a better understanding
of this particular re-entrant behavior.


title:
Enhancement of microbial motility due to speed-dependent nutrient
  absorption

abstract:
  Marine microorganisms often reach high swimming speeds, either to take
advantage of evanescent nutrient patches or to beat Brownian forces. Since this
implies that a sizable part of their energetic budget must be allocated to
motion, it is reasonable to assume that some fast-swimming microorganisms may
increase their nutrient intake by increasing their speed v. We formulate a
model to investigate this hypothesis and its consequences, finding the steady
state solutions and analyzing their stability. Surprisingly, we find that even
modest increases in nutrient absorption may lead to a significant increase of
the microbial speed. In fact, evaluations obtained using realistic parameter
values for bacteria indicate that the speed increase due to the enhanced
nutrient absorption may be quite large.


title:
Experimental Determination of p-wave Scattering Parameters in ultracold
  6Li atoms

abstract:
  We report the experimental determination of the scattering parameters for a
p-wave Feshbach resonance in a single component Fermi gas of 6Li atoms in the
lowest spin state. The time scale of the cross-dimensional relaxation reflects
the elastic scattering rate of the atoms, and scattering parameters are
determined from the scattering rate as a function of magnetic field by taking
into account the momentum distribution and inhomogeneous density profile of the
atoms in a trap. Precise determination of the scattering parameters for a
p-wave Feshbach resonance is an important step toward the realization of a
p-wave superfluid in an ultracold atomic gas.


title:
Coronal magnetic topology and the production of solar impulsive
  energetic electrons

abstract:
  We investigate two candidate solar sources or active regions (ARs) in
association with a solar impulsive energetic electron (SIEE) event on 2002
October 20. The solar particle release (SPR) times of SIEEs are derived by
using their velocity dispersion with consideration of the instrumental effect.
It is found that there are double electron injections at the Sun. The
low-energy (<13 keV) electron injection coincides with a C6.6 flare in AR10154
and is accompanied with prominent type III radio bursts rather than a stronger
M1.8 flare in AR10160. The M1.8 flare produces, however, faint type III radio
bursts. Whereas electrons of 25 to 300 keV are released 9 min later when a
jet-like CME travels to 2.6 solar radii. We further examine the coronal
magnetic configurations above the two ARs based on the potential field source
surface (PFSS) model. It is found that open field lines, rooted in AR10154 and
well connected to the Earth, provide escaping channels for energetic electrons.
Only a small portion of magnetic fields are opened above AR10160, being
responsible for the faint type III radio bursts. These lines are, however, not
well connected, making it impossible for SIEEs detection by near-Earth
spacecraft. The results appear to establish a physical link between coronal
magnetic topology, formation of type III radio bursts, and production of SIEEs.


title: Nanoscale capacitance: a classical charge-dipole approximation

abstract:
  Modeling nanoscale capacitance presents particular challenge because of
dynamic contribution from electrodes, which can usually be neglected in
modeling macroscopic capacitance and nanoscale conductance. We present a model
to calculate capacitances of nano-gap configurations and define effective
capacitances of nanoscale structures. The model is implemented by using a
classical atomic charge-dipole approximation and applied to calculate
capacitance of a carbon nanotube nano-gap and effective capacitance of a
buckyball inside the nano-gap. Our results show that capacitance of the carbon
nanotube nano-gap increases with length of electrodes which demonstrates the
important roles played by the electrodes in dynamic properties of nanoscale
circuits.


title:
Maximal displacement of a branching random walk in time-inhomogeneous
  environment

abstract:
  Consider a branching random walk evolving in a macroscopic time-inhomogeneous
environment, that scales with the length $n$ of the process under study. We
compute the first two terms of the asymptotic of the maximal displacement at
time $n$. The coefficient of the first (ballistic) order is obtained as the
solution of an optimization problem, while the second term, of order $n^{1/3}$,
comes from time-inhomogeneous random walk estimates, that may be of independent
interest. This result partially answers a conjecture of Fang and Zeitouni. Same
techniques are used to obtain the asymptotic of other quantities, such as the
consistent maximal displacement.


title:
Structure analysis of the generalized correlator of quark and gluon for
  a spin-1/2 target

abstract:
  We analyze the structure of generalized off-diagonal and transverse-momentum
dependent quark-quark and gluon-gluon correlators for a spin-1/2 hadron. Using
the light-front formalism, we provide a parametrization in terms of the parton
generalized transverse-momentum dependent distributions that emphasizes the
multipole structure of the correlator. The results for the quark-quark
correlation functions are consistent with an alternative parametrization given
in terms of Lorentz covariant structures. The parametrization for the
gluon-gluon generalized correlator is presented for the first time and allows
one to introduce new correlation functions which can be relevant for
phenomenological applications.


title: Multi-photon absorption limits to heralded single photon sources

abstract:
  Single photons are of paramount importance to future quantum technologies,
including quantum communication and computation. Nonlinear photonic devices
using parametric processes offer a straightforward route to generating photons,
however additional nonlinear processes may come into play and interfere with
these sources. Here we analyse these sources in the presence of multi-photon
processes for the first time. We conduct experiments in silicon and gallium
indium phosphide photonic crystal waveguides which display inherently different
nonlinear absorption processes, namely two-photon (TPA) and three-photon
absorption (ThPA), respectively. We develop a novel model capturing these
diverse effects which is in excellent quantitative agreement with measurements
of brightness, coincidence-to-accidental ratio (CAR) and second-order
correlation function g(2)(0), showing that TPA imposes an intrinsic limit on
heralded single photon sources. We devise a new figure of merit, the quantum
utility (QMU), enabling direct comparison and optimisation of single photon
sources.


title:
Multichromatic colour-magnitude diagrams of the globular cluster NGC
  6366

abstract:
  We present multichromatic isochrone fits to the colour-magnitude data of the
globular cluster NGC 6366, based on Hubble Space Telescope Advanced Camera for
Surveys/Wide Field Channel and Southern Astrophysical Research photometric
data. We corrected the photometric data for differential reddening and
calculated the mean ridge line of the colour-magnitude diagrams. We compared
the isochrones of Dartmouth Stellar Evolution Database and PAdova and TRieste
Stellar Evolution Code both with microscopic diffusion starting on the main
sequence. Bracketing all previous determinations of this cluster, we tested
metallicities from [Fe/H]=-1.00 to [Fe/H]=-0.50, and ages from 9 to 13 Gyr.
After determining the total to selective extinction ratio only from stars
belonging to this cluster, R_V=3.06+/-0.14, we found the parameters for this
cluster to be E(B-V)=0.69+/-0.02(int)+/-0.04(ext),
(m-M)_V=15.02+/-0.07(int)+/-0.13(ext), Age=11+/-1.15 Gyr. Evolutionary models
fail to reproduce the low-Teff sequence in multiband colour-magnitude diagrams,
indicating that they still have an incomplete physics. We found that the
Dartmouth Stellar Evolution Database isochrones better fit the subgiant branch
and low main sequence than the PAdova and TRieste Stellar Evolution Code.


title: Costly bilingualism model in a population with one zealot

abstract:
  We consider a costly bilingualism model in which one can take two strategies
in parallel. We investigate how a single zealot triggers the cascading behavior
and how the compatibility of the two strategies affects when interacting
patterns change. First, the role of the interaction range on the cascading is
studied by increasing the range from local to global. We find that people
sometimes do not favor to take the superior strategy even though its payoff is
higher than that of the inferior one. This is found to be caused by the local
interactions rather than the global ones. Applying this model to social
networks, we find that the location of the zealot is also important for larger
cascading in heterogeneous networks.


title: Dynamic core polarization in strong-field ionization of CO molecules

abstract:
  The orientation-dependent strong-field ionization of CO molecules is
investigated using the fully propagated three-dimensional time-dependent
Hartree-Fock theory. The full ionization results are in good agreement with
recent experiments. The comparisons between the full method and single active
orbital (SAO) method show that although the core electrons are generally more
tightly bounded and contribute little to the total ionization yields, their
dynamics cannot be ignored, which effectively modify the behaviors of electrons
in the highest occupied molecular orbital. By incorporating it into the SAO
method, we identify that the dynamic core polarization plays an important role
in the strong-field tunneling ionization of CO molecules, which is helpful for
future development of tunneling ionization theory of molecules beyond single
active electron approximation.


title:
Universally Elevating the Phase Transition Performance of Compressed
  Sensing: Non-Isometric Matrices are Not Necessarily Bad Matrices

abstract:
  In compressed sensing problems, $\ell_1$ minimization or Basis Pursuit was
known to have the best provable phase transition performance of recoverable
sparsity among polynomial-time algorithms. It is of great theoretical and
practical interest to find alternative polynomial-time algorithms which perform
better than $\ell_1$ minimization. \cite{Icassp reweighted l_1}, \cite{Isit
reweighted l_1}, \cite{XuScaingLaw} and \cite{iterativereweightedjournal} have
shown that a two-stage re-weighted $\ell_1$ minimization algorithm can boost
the phase transition performance for signals whose nonzero elements follow an
amplitude probability density function (pdf) $f(\cdot)$ whose $t$-th derivative
$f^{t}(0) \neq 0$ for some integer $t \geq 0$. However, for signals whose
nonzero elements are strictly suspended from zero in distribution (for example,
constant-modulus, only taking values `$+d$' or `$-d$' for some nonzero real
number $d$), no polynomial-time signal recovery algorithms were known to
provide better phase transition performance than plain $\ell_1$ minimization,
especially for dense sensing matrices. In this paper, we show that a
polynomial-time algorithm can universally elevate the phase-transition
performance of compressed sensing, compared with $\ell_1$ minimization, even
for signals with constant-modulus nonzero elements. Contrary to conventional
wisdoms that compressed sensing matrices are desired to be isometric, we show
that non-isometric matrices are not necessarily bad sensing matrices. In this
paper, we also provide a framework for recovering sparse signals when sensing
matrices are not isometric.


title: Weyl type bound on positive Interior Transmission Eigenvalues

abstract:
  This paper contains a lower bound of the Weyl type on the counting function
of the positive eigenvalues of the interior transmission eigenvalue problem
which justifies the existence of an infinite set of positive interior
transmission eigenvalues. We consider the classical transmission problem as
well as the case where the inhomogeneous medium contains an obstacle. One of
the essential components of the proof is an estimate for the D-t-N operator for
the Helmholtz equation for positive $\lambda$ that replaces the standard
parameter-elliptic estimate valid outside of the positive semi-axis.


title:
Global estimates and blow-up criteria for the generalized Hunter-Saxton
  system

abstract:
  The generalized, two-component Hunter-Saxton system comprises several
well-known models of fluid dynamics and serves as a tool for the study of
one-dimensional fluid convection and stretching. In this article a general
representation formula for periodic solutions to the system, which is valid for
arbitrary values of parameters $(\lambda,\kappa)\in\mathbb{R}\times\mathbb{R}$,
is derived. This allows us to examine in great detail qualitative properties of
blow-up as well as the asymptotic behaviour of solutions, including convergence
to steady states in finite or infinite time.


title:
AWGN Channel Capacity of Energy Harvesting Transmitters with a Finite
  Energy Buffer

abstract:
  We consider an AWGN channel with a transmitter powered by an energy
harvesting source. The node is equipped with a finite energy buffer. Such a
system can be modelled as a channel with side information (about energy in the
energy buffer) causally known at the transmitter. The receiver may or may not
have the side information. We prove that Markov energy management policies are
sufficient to achieve the capacity of the system and provide a single letter
characterization for the capacity. The computation of the capacity is
expensive. Therefore, we discuss an achievable scheme that is easy to compute.
This achievable rate converges to the infinite buffer capacity as the buffer
length increases.


title:
Spin-orbit interaction induced spin selective transmission through a
  multi-terminal mesoscopic ring

abstract:
  Spin dependent transport in a multi-terminal mesoscopic ring is investigated
in presence of Rashba and Dresselhaus spin-orbit interactions. Within a
tight-binding framework we use a general spin density matrix formalism to
evaluate all three components ($P_x$, $P_y$ and $P_z$) of the polarization
vector associated with the charge current through the outgoing leads. It
explores the dynamics of the spin polarization vector of current propagating
through the system subjected to the Rashba and/or the Dresselhaus spin-orbit
couplings. The sensitivity of the polarization components on the electrode-ring
interface geometry is discussed in detail. Our present analysis provides an
understanding of the coupled spin and electron transport in mesoscopic bridge
systems.


title:
The role of the Gamma-Eddington ratio relation on the X-ray Baldwin
  effect in Active Galactic Nuclei

abstract:
  The X-ray Baldwin effect is the inverse correlation between the equivalent
width (EW) of the narrow component of the iron Kalpha line and the X-ray
luminosity of active galactic nuclei (AGN). A similar trend has also been
observed between Fe Kalpha EW and the Eddington ratio (lambda_Edd). Using
Chandra/HEG results of Shu et al. (2010) and bolometric corrections we study
the relation between EW and the lambda_Edd, and find that log EW =
(-0.13+/-0.03)log(lambda_Edd) + 1.47. We explore the role of the known positive
correlation between the photon index of the primary X-ray continuum (Gamma) and
lambda_Edd on the X-ray Baldwin effect. We simulate the iron Kalpha line
emitted by populations of unabsorbed AGN considering 3 different geometries of
the reflecting material: toroidal, spherical-toroidal and slab. We find that
the Gamma-lambda_Edd correlation cannot account for the whole X-ray Baldwin
effect, unless a strong dependence of Gamma on lambda_Edd, such as the one
recently found by Risaliti et al. (2009) and Jin et al. (2012), is assumed. No
clear correlation is found between EW and Gamma. We conclude that a good
understanding of the slope of the Gamma-lambda_Edd relation is critical to
assess whether the trend plays a leading or rather a marginal role in the X-ray
Baldwin effect.