title:
The solvable Lie group $N_{6,28}$: an example of an almost
  $C_0(\mathcal{K})$-C*-algebra

abstract:
  Motivated by the description of the C*-algebra of the affine automorphism
group $N_{6,28}$ of the Siegel upper half-plane of degree 2 as an algebra of
operator fields defined over the unitary dual $\widehat{N_{6,28}}$ of the
group, we introduce a family of C*-algebras, which we call almost
$C_0(\mathcal{K})$, and we show that the C*-algebra of the group $N_{6,28}$
belongs to this class.


title: Truth Table Invariant Cylindrical Algebraic Decomposition

abstract:
  When using cylindrical algebraic decomposition (CAD) to solve a problem with
respect to a set of polynomials, it is likely not the signs of those
polynomials that are of paramount importance but rather the truth values of
certain quantifier free formulae involving them. This observation motivates our
article and definition of a Truth Table Invariant CAD (TTICAD).
  In ISSAC 2013 the current authors presented an algorithm that can efficiently
and directly construct a TTICAD for a list of formulae in which each has an
equational constraint. This was achieved by generalising McCallum's theory of
reduced projection operators. In this paper we present an extended version of
our theory which can be applied to an arbitrary list of formulae, achieving
savings if at least one has an equational constraint. We also explain how the
theory of reduced projection operators can allow for further improvements to
the lifting phase of CAD algorithms, even in the context of a single equational
constraint.
  The algorithm is implemented fully in Maple and we present both promising
results from experimentation and a complexity analysis showing the benefits of
our contributions.


title: Detection of small exchange fields in S/F structures

abstract:
  Ferromagnetic materials with exchange fields E_ex smaller or of the order of
the superconducting gap Delta are important for applications of corresponding
(s-wave) superconductor/ ferromagnet/ superconductor (SFS) junctions. Presently
such materials are not known but there are several proposals how to create
them. Small exchange fields are in principle difficult to detect. Based on our
results we propose reliable detection methods of such small E_ex. For exchange
fields smaller than the superconducting gap the subgap differential conductance
of the normal metal - ferromagnet - insulator - superconductor (NFIS) junction
shows a peak at the voltage bias equal to the exchange field of the
ferromagnetic layer, eV=E_ex. Thus measuring the subgap conductance one can
reliably determine small E_ex < Delta. In the opposite case E_ex > Delta one
can determine the exchange field in scanning tunneling microscopy (STM)
experiment. The density of states of the FS bilayer measured at the outer
border of the ferromagnet shows a peak at the energy equal to the exchange
field, E=E_ex. This peak can be only visible for small enough exchange fields
of the order of few Delta.


title: Cylindrical Algebraic Sub-Decompositions

abstract:
  Cylindrical algebraic decompositions (CADs) are a key tool in real algebraic
geometry, used primarily for eliminating quantifiers over the reals and
studying semi-algebraic sets. In this paper we introduce cylindrical algebraic
sub-decompositions (sub-CADs), which are subsets of CADs containing all the
information needed to specify a solution for a given problem.
  We define two new types of sub-CAD: variety sub-CADs which are those cells in
a CAD lying on a designated variety; and layered sub-CADs which have only those
cells of dimension higher than a specified value. We present algorithms to
produce these and describe how the two approaches may be combined with each
other and the recent theory of truth-table invariant CAD.
  We give a complexity analysis showing that these techniques can offer
substantial theoretical savings, which is supported by experimentation using an
implementation in Maple.


title: The modal logic of Reverse Mathematics

abstract:
  The implication relationship between subsystems in Reverse Mathematics has an
underlying logic, which can be used to deduce certain new Reverse Mathematics
results from existing ones in a routine way. We use techniques of modal logic
to formalize the logic of Reverse Mathematics into a system that we name
s-logic. We argue that s-logic captures precisely the "logical" content of the
implication and nonimplication relations between subsystems in Reverse
Mathematics. We present a sound, complete, decidable, and compact tableau-style
deductive system for s-logic, and explore in detail two fragments that are
particularly relevant to Reverse Mathematics practice and automated theorem
proving of Reverse Mathematics results.


title:
Spectral Theory near Thresholds for Weak Interactions with Massive
  Particles

abstract:
  We consider a Hamiltonian describing the weak decay of the massive vector
boson Z0 into electrons and positrons. We show that the spectrum of the
Hamiltonian is composed of a unique isolated ground state and a semi-axis of
essential spectrum. Using a suitable extension of Mourre's theory, we prove
that the essential spectrum below the boson mass is purely absolutely
continuous.


title:
Shape and pairing fluctuations effects on neutrinoless double beta decay
  nuclear matrix elements

abstract:
  Nuclear matrix elements (NME) for the most promising candidates to detect
neutrinoless double beta decay have been computed with energy density
functional methods including deformation and pairing fluctuations explicitly on
the same footing. The method preserves particle number and angular momentum
symmetries and can be applied to any decay without additional fine tunings. The
finite range density dependent Gogny force is used in the calculations. An
increase of $10\%-40\%$ in the NME with respect to the ones found without the
inclusion of pairing fluctuations is obtained, reducing the predicted
half-lives of these isotopes.


title:
Correlations and neutrinoless $\beta\beta$ decay nuclear matrix elements
  of $pf$-shell nuclei

abstract:
  We calculate the nuclear matrix elements (NMEs) for neutrinoless double-beta
decays ($0\nu\beta\beta$) of $pf$-shell nuclei using the shell model (SM) and
energy density functional (EDF) methods. The systematic study of non-physical
decays (except for $^{48}$Ca) of Ca$\rightarrow$Ti, Ti$\rightarrow$Cr and
Cr$\rightarrow$Fe allows for a detailed comparison between the two nuclear
structure approaches. We observe that while the dominant Gamow-Teller part of
the NME differs roughly by a factor of two between SM and EDF, when we restrict
the calculations to spherical EDF states and seniority-zero SM configurations,
the NMEs obtained by both methods are strikingly similar. This points out to
the important role of nuclear structure correlations for $0\nu\beta\beta$ decay
NMEs. We identify correlations associated with high-seniority components in the
initial and final states of the decay as one of the reasons for the
discrepancies between SM and EDF results. We also explore exact projection to
good isospin, and conclude that it has only a moderate effect in the
Gamow-Teller part of the NMEs but strongly affects the Fermi contribution. This
work opens up the door for NME benchmarks between different theoretical
approaches, and constitutes a step forward towards more reliable estimations of
the NMEs.


title: Why are some BL Lacs detected by \fermi, but others not ?

abstract:
  By cross-correlating an archival sample of 170 BL Lacs with 2 year \fermilat
AGN sample, we have compiled a sample of 100 BL Lacs with \fermi detection
(FBLs), and a sample of 70 non-\fermi BL Lacs (NFBLs). We compared various
parameters of FBLs with those of NFBLs, including the redshift, the low
frequency radio luminosity at 408 MHz ($L_{\rm 408MHz}$), the absolute
magnitude of host galaxies ($M_{\rm host}$), the polarization fraction from
NVSS survey ($P_{\rm NVSS}$), the observed arcsecond scale radio core flux at 5
GHz ($F_{\rm core}$) and jet Doppler factor; all the parameters are directly
\textbf{measured} or derived from available data from literatures. We found
that the Doppler factor is on average larger in FBLs than in NFBLs, and the
$Fermi~ \gamma$-ray detection rate is higher in sources with higher Doppler
factor. In contrast, there are no significant differences in terms of the
intrinsic parameters of redshift, $ L_{\rm 408MHz}$, $ M_{\rm host}$ and $
P_{\rm NVSS}$. FBLs seem to have a higher probability of exhibiting measurable
proper motion. These results strongly indicate a higher beaming effect in FBLs
compared to NFBLs. The radio core flux is found to be strongly correlated with
$\gamma$-ray flux, which remains after excluding the common dependence of the
Doppler factor. At the fixed Doppler factor, FBLs have systematically larger
radio core flux than NFBLs, implying lower $\gamma$-ray emission in NFBLs since
the radio and $\gamma$-ray flux are significantly correlated. Our results
indicate that the Doppler factor is an important parameter of $\gamma$-ray
detection, the non-detection of $\gamma$-ray emission in NFBLs is likely due to
low beaming effect, and/or low intrinsic $\gamma$-ray flux, and the gamma-rays
are likely produced co-spatially with the arcsecond-scale radio core radiation
and mainly through the SSC process.


title:
Nonlinear GLR-MQ evolution equation and Q^2-evolution of gluon
  distribution function

abstract:
  In this paper we have solved the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu
(GLR-MQ) evolution equation for gluon distribution function G(x,Q^2) and
studied the effects of the nonlinear GLR-MQ corrections to the Leading Order
(LO) Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations.
Here we incorporate a Regge like behaviour of gluon distribution function to
obtain the solution of GLR-MQ evolution equation. We have also investigated the
Q^2-dependence of gluon distribution function from the solution of GLR-MQ
evolution equation. Moreover it is interesting to observe from our results that
nonlinearities increase with decreasing correlation radius (R) between two
interacting gluons. Results also confirm that the steep behavior of gluon
distribution function is observed at R=5 GeV^{-1}, whereas it is lowered at R=2
GeV^{-1} with decreasing x as Q^2 increases. In this work we have also checked
the sensitivity of \lambda_G in our calculations. Our computed results are
compared with those obtained by the global DGLAP fits to the parton
distribution functions viz. GRV, MRST, MSTW and with the EHKQS model.


title:
Numerical algorithms for the forward and backward fractional Feynman-Kac
  equations

abstract:
  The Feynman-Kac equations are a type of partial differential equations
describing the distribution of functionals of diffusive motion. The probability
density function (PDF) of Brownian functionals satisfies the Feynman-Kac
formula, being a Schr\"{o}dinger equation in imaginary time. The functionals of
no-Brownian motion, or anomalous diffusion, follow the fractional Feynman-Kac
equation [J. Stat. Phys. 141, 1071-1092, 2010], where the fractional
substantial derivative is involved. Based on recently developed discretized
schemes for fractional substantial derivatives [arXiv:1310.3086], this paper
focuses on providing algorithms for numerically solving the forward and
backward fractional Feynman-Kac equations; since the fractional substantial
derivative is non-local time-space coupled operator, new challenges are
introduced comparing with the general fractional derivative. Two ways (finite
difference and finite element) of discretizing the space derivative are
considered. For the backward fractional Feynman-Kac equation, the numerical
stability and convergence of the algorithms with first order accuracy are
theoretically discussed; and the optimal estimates are obtained. For all the
provided schemes, including the first order and high order ones, of both
forward and backward Feynman-Kac equations, extensive numerical experiments are
performed to show their effectiveness.


title: Critical Nodes In Directed Networks

abstract:
  Critical nodes or "middlemen" have an essential place in both social and
economic networks when considering the flow of information and trade. This
paper extends the concept of critical nodes to directed networks. We identify
strong and weak middlemen. Node contestability is introduced as a form of
competition in networks; a duality between uncontested intermediaries and
middlemen is established. The brokerage power of middlemen is formally
expressed and a general algorithm is constructed to measure the brokerage power
of each node from the networks adjacency matrix. Augmentations of the brokerage
power measure are discussed to encapsulate relevant centrality measures. We use
these concepts to identify and measure middlemen in two empirical
socio-economic networks, the elite marriage network of Renaissance Florence and
Krackhardt's advice network.


title: Final Binary Stars Results From The VLT Lunar Occultations Program

abstract:
  We report on 13 sub-arcsecond binaries, detected by means of lunar
occultations in the near-infrared at the ESO Very Large Telescope. They are all
first-time detections, except for the visual binary HD~158122 which we resolved
for the first time in the near infrared. The primaries have magnitudes in the
range $K$=4.5 to 10.0, and the companions in the range $K$=6.8 to 11.1. The
magnitude differences have a median value of 2.4, with the largest being 4.6.
The projected separations are in the range 4 to 168 milliarcseconds with a
median of 13 milliarcseconds. We discuss and compare our results with the
available literature.
  With this paper, we conclude the mining for binary star detections in the
volume of 1226 occultations recorded at the VLT with the ISAAC instrument. We
expect that the majority of these binaries may be unresolvable by adaptive
optics on current telescopes, and they might be challenging for long-baseline
interferometry. However they constitute an interesting sample for future larger
telescopes and for astrometric missions such as GAIA.


title: Tunneling-induced angular momentum for single cold atoms

abstract:
  We study the generation of angular momentum carrying states for a single cold
particle by breaking the symmetry of a spatial adiabatic passage process in a
two-dimensional system consisting of three harmonic potential wells. By
following a superposition of two eigenstates of the system, a single cold
particle is completely transferred to the degenerate first excited states of
the final trap, which are resonantly coupled via tunneling to the ground states
of the initial and middle traps. Depending on the total time of the process,
angular momentum is generated in the final trap, with values that oscillate
between $\pm\hbar$. This process is discussed in terms of the asymptotic
eigenstates of the individual wells and the results have been checked by
simulations of the full two-dimensional Schr\"odinger equation.


title: Conformal relativity with hypercomplex variables

abstract:
  Majorana's arbitrary spin theory is considered in a hyperbolic complex
representation. The underlying differential equation is embedded into the gauge
field theories of Sachs and Carmeli. In particular, the approach of Sachs can
serve as a unified theory of general relativity and electroweak interactions.
The method is extended to conformal space with the intention to introduce the
strong interaction. It is then possible to use the wave equation, operating on
representation functions of the conformal group, to describe the dynamics of
matter fields. The resulting gauge groups resemble closely the gauge symmetries
of Glashow-Salam-Weinberg and the Standard Model.


title: Chemical Potential and Quantum Hall Ferromagnetism in Bilayer Graphene

abstract:
  Bilayer graphene has a unique electronic structure influenced by a complex
interplay between various degrees of freedom. We probe its chemical potential
using double bilayer graphene heterostructures, separated by a hexagonal boron
nitride dielectric. The chemical potential has a non-linear carrier density
dependence, and bears signatures of electron-electron interactions. The data
allow a direct measurement of the electric field-induced bandgap at zero
magnetic field, the orbital Landau level (LLs) energies, and the broken
symmetry quantum Hall state gaps at high magnetic fields. We observe
spin-to-valley polarized transitions for all half-filled LLs, as well as
emerging phases at filling factors \nu = 0 and \nu = +-2. Furthermore, the data
reveal interaction-driven negative compressibility and electron-hole asymmetry
in N = 0, 1 LLs.


title: Plurals: individuals and sets in a richly typed semantics

abstract:
  We developed a type-theoretical framework for natural lan- guage semantics
that, in addition to the usual Montagovian treatment of compositional
semantics, includes a treatment of some phenomena of lex- ical semantic:
coercions, meaning, transfers, (in)felicitous co-predication. In this setting
we see how the various readings of plurals (collective, dis- tributive,
coverings,...) can be modelled.


title: Shape deformation analysis from the optimal control viewpoint

abstract:
  A crucial problem in shape deformation analysis is to determine a deformation
of a given shape into another one, which is optimal for a certain cost. It has
a number of applications in particular in medical imaging. In this article we
provide a new general approach to shape deformation analysis, within the
framework of optimal control theory, in which a deformation is represented as
the flow of diffeomorphisms generated by time-dependent vector fields. Using
reproducing kernel Hilbert spaces of vector fields, the general shape
deformation analysis problem is specified as an infinite-dimensional optimal
control problem with state and control constraints. In this problem, the states
are diffeomorphisms and the controls are vector fields, both of them being
subject to some constraints. The functional to be minimized is the sum of a
first term defined as geometric norm of the control (kinetic energy of the
deformation) and of a data attachment term providing a geometric distance to
the target shape. This point of view has several advantages. First, it allows
one to model general constrained shape analysis problems, which opens new
issues in this field. Second, using an extension of the Pontryagin maximum
principle, one can characterize the optimal solutions of the shape deformation
problem in a very general way as the solutions of constrained geodesic
equations. Finally, recasting general algorithms of optimal control into shape
analysis yields new efficient numerical methods in shape deformation analysis.
Overall, the optimal control point of view unifies and generalizes different
theoretical and numerical approaches to shape deformation problems, and also
allows us to design new approaches. The optimal control problems that result
from this construction are infinite dimensional and involve some constraints,
and thus are nonstandard. In this article we also provide a rigorous and
complete analysis of the infinite-dimensional shape space problem with
constraints and of its finite-dimensional approximations.


title:
How well does the Friends-of-Friends algorithm recover group properties
  from galaxy catalogs limited in both distance and luminosity?

abstract:
  We test the Friends-of-Friends (FoF) grouping algorithm, which depends on two
linking lengths (LLs), plane-of-sky and line-of-sight (LOS), normalized to the
mean nearest neighbor separation of field galaxies. We argue, on theoretical
grounds, that LLs should be $b_\perp \simeq 0.11$, and $b_\parallel \simeq 1.3$
to recover 95% of all galaxies with projected radii within the virial radius
$r_{200}$ and 95% of the galaxies along the LOS. We then predict that 80 to 90%
of the galaxies in FoF groups should lie within their parent real-space groups
(RSGs), defined within their virial spheres. We test the FoF extraction for
16x16 pairs of LLs, using subsamples of galaxies, doubly complete in distance
and luminosity, of a flux-limited mock SDSS galaxy catalog. We find that
massive RSGs are more prone to fragmentation, while the fragments typically
have low estimated mass, with typically 30% of groups of low and intermediate
estimated mass being fragments. Group merging rises drastically with estimated
mass. For groups of 3 or more galaxies, galaxy completeness and reliability are
both typically better than 80% (after discarding the fragments). Estimated
masses of extracted groups are biased low, by up to a factor 4 at low richness,
while the inefficiency of mass estimation improves from 0.85 dex to 0.2 dex
when moving from low to high multiplicity groups. The optimal LLs depend on the
scientific goal for the group catalog. We propose $b_\perp \simeq 0.07$, with
$b_\parallel \simeq 1.1$ for studies of environmental effects, $b_\parallel
\simeq 2.5$ for cosmographic studies and $b_\parallel \simeq 5$ for followups
of individual groups.


title:
Photons in a cold axion background and strong magnetic fields:
  polarimetric consequences

abstract:
  In this work we analyze the propagation of photons in an environment where a
strong magnetic field (perpendicular to the photon momenta) coexists with an
oscillating cold axion background with the characteristics expected from dark
matter in the galactic halo. Qualitatively, the main effect of the combined
background is to produce a three-way mixing among the two photon polarizations
and the axion. It is interesting to note that in spite of the extremely weak
interaction of photons with the cold axion background, its effects compete with
those coming from the magnetic field in some regions of the parameter space. We
determine (with one plausible simplification) the proper frequencies and
eigenvectors as well as the corresponding photon ellipticity and induced
rotation of the polarization plane that depend both on the magnetic field and
the local density of axions. We also comment on the possibility that some of
the predicted effects could be measured in optical table-top experiments.


title: Between two moments

abstract:
  In this short note, we draw attention to a relation between two Horn
polytopes which is proved in [Chenciner-Jim\'enez P\'erez] as the result on the
one side of a deep combinatorial result in [Fomin,Fulton, Li,Poon], on the
other side of a simple computation involving complex structures. This suggested
an inequality between Littlewood-Richardson coefficients which we prove using
the symmetric characterization of these coefficients given in
[Carr\'e,Leclerc].


title:
The light curve in supernova modeled by a continuous radioactive decay
  of $^{56}$Ni

abstract:
  The UVOIR bolometric light curves are usually modeled by the radioactive
decay. In order to model more precisely the absolute/apparent magnitude versus
time relationship the continuous production of radioactive isotopes is
introduced. A differential equation of the first order with separable variables
is solved.


title: Entangling two distinguishable quantum bright solitons via collisions

abstract:
  The generation of mesoscopic Bell states via collisions of distinguishable
bright solitons has been suggested in Phys. Rev. Lett. 111, 100406 (2013).
Here, we extend our former proposal to two hyperfine states of 85Rb instead of
two different atomic species, thus simplifying possible experimental
realisations. A calculation of the $s$-wave scattering lengths for the
hyperfine states $(f,m_f)=(2,+2)$ and $(3,+2)$ identifies parameter regimes
suitable for the creation of Bell states with an advantageously broad Feshbach
resonance. We show the generation of Bell states using the truncated Wigner
method for the soliton's centre of mass and demonstrate the validity of this
approach by a comparison to a mathematically rigorous effective potential
treatment of the quantum many-particle problem.


title:
Bright excitons in monolayer transition metal dichalcogenides: from
  Dirac cones to Dirac saddle points

abstract:
  In monolayer transition metal dichalcogenides, tightly bound excitons have
been discovered with a valley pseudospin that can be optically addressed
through polarization selection rules. Here, we show that this valley pseudospin
is strongly coupled to the exciton center-of-mass motion through electron-hole
exchange. This coupling realizes a massless Dirac cone with chirality index I=2
for excitons inside the light cone, i.e. bright excitons. Under moderate
strain, the I=2 Dirac cone splits into two degenerate I=1 Dirac cones, and
saddle points with a linear Dirac spectrum emerge in the bright exciton
dispersion. Interestingly, after binding an extra electron, the charged exciton
becomes a massive Dirac particle associated with a large valley Hall effect
protected from intervalley scattering. Our results point to unique
opportunities to study Dirac physics, with exciton's optical addressability at
specifiable momentum, energy and pseudospin. The strain-tunable valley-orbit
coupling also implies new structures of exciton condensates, new
functionalities of excitonic circuits, and possibilities for mechanical control
of valley pseudospin.


title: Kinetic Inductance Magnetometer

abstract:
  Ultrasensitive magnetic field detection is utilized in the fields of science,
medicine and industry. We report on a novel magnetometer relying on the kinetic
inductance of superconducting material. The kinetic inductance exhibits a
non-linear response with respect to DC current, a fact that is exploited by
applying magnetic flux through a superconducting loop to generate a shielding
current and a change in the inductance of the loop. The magnetometer is
arranged into a resonator, allowing readout through a transmission measurement
that makes the device compatible with radio frequency multiplexing techniques.
The device is fabricated using a single thin-film layer of NbN, simplifying the
fabrication process compared to existing magnetometer technologies
considerably. Our experimental data, supported by theory, demonstrates a
magnetometer having potential to replace established technology in applications
requiring ultra-high sensitivity.


title:
Nonperturbative tests of the renormalization of mixed clover-staggered
  currents in lattice QCD

abstract:
  The Fermilab Lattice and MILC collaborations have shown in one-loop lattice
QCD perturbation theory that the renormalization constants of vector and
axial-vector mixed clover-asqtad currents are closely related to the product of
those for clover-clover and asqtad-asqtad (local) vector currents. To be useful
for future higher precision calculations this relationship must be valid beyond
one-loop and very general. We test its validity nonperturbatively using clover
and Highly Improved Staggered (HISQ) strange quarks, utilising the absolute
normalization of the HISQ temporal axial current. We find that the
renormalization of the mixed current differs from the square root of the
product of the pure HISQ and pure clover currents by $2-3\%$. We also compare
discretization errors between the clover and HISQ formalisms.


title: MRF denoising with compressed sensing and adaptive filtering

abstract:
  The recently proposed Magnetic Resonance Fingerprinting (MRF) technique can
simultaneously estimate multiple parameters through dictionary matching. It has
promising potentials in a wide range of applications. However, MRF introduces
errors due to undersampling during the data acquisition process and the limit
of dictionary resolution. In this paper, we investigate the error source of MRF
and propose the technologies of improving the quality of MRF with compressed
sensing, error prediction by decision trees, and adaptive filtering.
Experimental results support our observations and show significant improvement
of the proposed technologies.


title: Few-body Physics in a Many-body World

abstract:
  The study of quantum mechanical few-body systems is a century old pursuit
relevant to countless subfields of physics. While the two-body problem is
generally considered to be well-understood theoretically and numerically,
venturing to three or more bodies brings about complications but also a host of
interesting phenomena. In recent years, the cooling and trapping of atoms and
molecules has shown great promise to provide a highly controllable environment
to study few-body physics. However, as is true for many systems where few-body
effects play an important role the few-body states are not isolated from their
many-body environment. An interesting question then becomes if or (more
precisely) when we should consider few-body states as effectively isolated and
when we have to take the coupling to the environment into account. Using some
simple, yet non-trivial, examples I will try to suggest possible approaches to
this line of research.


title:
Spin Dephasing as a Probe of Mode Temperature, Motional State
  Distributions, and Heating Rates in a 2D Ion Crystal

abstract:
  We employ spin-dependent optical dipole forces to characterize the transverse
center-of-mass (COM) motional mode of a two-dimensional Wigner crystal of
hundreds of $^9$Be$^+$. By comparing the measured spin dephasing produced by
the spin-dependent force with the predictions of a semiclassical dephasing
model, we obtain absolute mode temperatures in excellent agreement with both
the Doppler laser cooling limit and measurements obtained from a previously
published technique (B. C. Sawyer et al. Phys. Rev. Lett. \textbf{108}, 213003
(2012)). Furthermore, the structure of the dephasing histograms allows for
discrimination between initial thermal and coherent states of motion. We also
apply the techniques discussed here to measure, for the first time, the ambient
heating rate of the COM mode of a 2D Coulomb crystal in a Penning trap. This
measurement places an upper limit on the anomalous single-ion heating rate due
to electric field noise from the trap electrode surfaces of
$\frac{d\bar{n}}{dt}\sim 5$ s$^{-1}$ for our trap at a frequency of 795 kHz,
where $\bar{n}$ is the mean occupation of quantized COM motion in the axial
harmonic well.


title: Emergence of Riemannian geometry and the massive graviton

abstract:
  We overview a new mechanism whereby classical Riemannian geometry emerges out
of the differential structure on quantum spacetime, as extension data for the
classical algebra of differential forms. Outcomes for physics include a new
formula for the standard Levi-Civita connection, a new point of view of the
cosmological constant as a very small mass for the graviton of around
$10^{-33}$ev, and a weakening of metric-compatibility in the presence of
torsion. The same mechanism also provides a new construction for quantum
bimodule connections on quantum spacetimes and a new approach to the quantum
Ricci tensor.


title:
Pullback attractor for a non local non-autonomous evolution equation in
  an unbounded domain

abstract:
  In this work we consider the non local evolution equation with time-dependent
terms which arises in models of phase separation in $\mathbb{R}^N$ \[
\partial_t u=- u + g \left(\beta(J*u) +\beta h(t,u)\right) \] under some
restrictions on $h$, growth restrictions on the nonlinear term $g$ and
$\beta>1$. We prove, under suitable assumptions, existence, regularity and
upper-semicontinuity of pullback attractors with respect to functional
parameter $h(t)$ in some weighted spaces.


title: Energy flow in periodic thermodynamics

abstract:
  A key quantity characterizing a time-periodically forced quantum system
coupled to a heat bath is the energy flowing in the steady state through the
system into the bath, where it is dissipated. We derive a general expression
which allows one to compute this energy dissipation rate for a heat bath
consisting of a large number of harmonic oscillators, and work out two
analytically solvable model examples. In particular, we distinguish between
genuine transitions effectuating a change of the systems's Floquet state, and
pseudo-transitions preserving that state; the latter are shown to yield an
important contribution to the total dissipation rate. Our results suggest
possible driving-mediated heating and cooling schemes on the quantum level.
They also indicate that a driven system does not necessarily occupy only a
single Floquet state when being in contact with a zero-temperature bath.


title: Generalized Coupled-line All-Pass Phasers

abstract:
  Generalized coupled-line all-pass phasers, based on transversally-cascaded
(TC), longitudinally-cascaded (LC) and hybrid-cascaded (HC) coupled
transmission line sections, are presented and demonstrated using analytical,
full-wave and experimental results. It is shown that for N commensurate
coupled-line sections, LC and TC phasers exhibit N group delay peaks per
coupled-line section harmonic frequency band, in contrast to the TC
configuration, which exhibits only one peak within this band. It is also shown
that for a given maximum achievable coupling-coefficient, the HC configuration
provides the largest group delay swing. A wave-interference analysis is finally
applied to the various coupled-line phasers, explaining their unique group
delay characteristics based on physical wave-propagation mechanisms.


title:
G-Doob-Meyer Decomposition and its Application in Bid-Ask Pricing for
  American Contingent Claim Under Knightian Uncertainty

abstract:
  The target of this paper is to establish the bid-ask pricing frame work for
the American contingent claims against risky assets with G-asset price systems
(see \cite{Chen2013b}) on the financial market under Knight uncertainty. First,
we prove G-Dooby-Meyer decomposition for G-supermartingale. Furthermore, we
consider bid-ask pricing American contingent claims under Knight uncertain, by
using G-Dooby-Meyer decomposition, we construct dynamic superhedge stragies for
the optimal stopping problem, and prove that the value functions of the optimal
stopping problems are the bid and ask prices of the American contingent claims
under Knight uncertain. Finally, we consider a free boundary problem, prove the
strong solution existence of the free boundary problem, and derive that the
value function of the optimal stopping problem is equivalent to the strong
solution to the free boundary problem.


title:
Velocity-Gradient Probability Distribution Functions in a Lagrangian
  Model of Turbulence

abstract:
  The Recent Fluid Deformation Closure (RFDC) model of lagrangian turbulence is
recast in path-integral language within the framework of the Martin-Siggia-Rose
functional formalism. In order to derive analytical expressions for the
velocity-gradient probability distribution functions (vgPDFs), we carry out
noise renormalization in the low-frequency regime and find approximate extrema
for the Martin-Siggia-Rose effective action. We verify, with the help of Monte
Carlo simulations, that the vgPDFs so obtained yield a close description of the
single-point statistical features implied by the original RFDC stochastic
differential equations.


title: Inverse melting in a two-dimensional off-lattice model

abstract:
  We carry out computer simulations of a simple, two-dimensional off-lattice
model that exhibits inverse melting. The monodisperse system comprises
core-softened disks interacting through a repulsive square shoulder located
inside an attractive square well. By systematically varying the potential
parameters, we increase the pressure range over which the liquid freezes to a
crystal upon isobaric heating. The effect is largely controlled by the extent
of the shoulder. Despite occurring in two dimensions, the melting transition is
first order and to a liquid, rather than to a hexatic or quasicrystal phase. We
also provide comment on a commonly employed correlation function used to
determine the degree of translational ordering in a system.


title:
Perturbative calculation of critical exponents for the Bose-Hubbard
  model

abstract:
  We develop a strategy for calculating critical exponents for the Mott
insulator-to-superfluid transition shown by the Bose-Hubbard model. Our
approach is based on the field-theoretic concept of the effective potential,
which provides a natural extension of the Landau theory of phase transitions to
quantum critical phenomena. The coefficients of the Landau expansion of that
effective potential are obtained by high-order perturbation theory. We
counteract the divergency of the weak-coupling perturbation series by including
the seldom considered Landau coefficient $a_6$ into our analysis. Our
preliminary results indicate that the critical exponents for both the
condensate density and the superfluid density, as derived from the
two-dimensional Bose-Hubbard model, deviate by less than $1\%$ from the best
known estimates computed so far for the three-dimensional $XY$ universality
class.


title:
Quasi-periodic motions in a special class of dynamical equations with
  dissipative effects: a pair of detection methods

abstract:
  We consider a particular class of equations of motion, generalizing to n
degrees of freedom the "dissipative spin--orbit problem", commonly studied in
Celestial Mechanics. Those equations are formulated in a pseudo-Hamiltonian
framework with action-angle coordinates; they contain a quasi-integrable
conservative part and friction terms, assumed to be linear and isotropic with
respect to the action variables. In such a context, we transfer two methods
determining quasi-periodic solutions, which were originally designed to analyze
purely Hamiltonian quasi-integrable problems.
  First, we show how the frequency map analysis can be adapted to this kind of
dissipative models. Our approach is based on a key remark: the method can work
as usual, by studying the behavior of the angular velocities of the motions as
a function of the so called "external frequencies", instead of the actions.
Moreover, we explicitly implement the Kolmogorov's normalization algorithm for
the dissipative systems considered here. In a previous article, we proved a
theoretical result: such a constructing procedure is convergent under the
hypotheses usually assumed in KAM theory. In the present work, we show that it
can be translated to a code making algebraic manipulations on a computer, so to
calculate effectively quasi-periodic solutions on invariant tori. Both the
methods are carefully tested, by checking that their predictions are in
agreement, in the case of the so called "dissipative forced pendulum".
Furthermore, the results obtained by applying our adaptation of the frequency
analysis method to the dissipative standard map are compared with some existing
ones in the literature.


title:
The model of a level crossing with a Coulomb band: exact probabilities
  of nonadiabatic transitions

abstract:
  We derive an exact solution of an explicitly time-dependent multichannel
model of quantum mechanical nonadiabatic transitions. Our model corresponds to
the case of a single linear diabatic energy level interacting with a band of an
arbitrary N states, for which the diabatic energies decay with time according
to the Coulomb law. We show that the time-dependent Schroedingier equation for
this system can be solved in terms of Meijer functions whose asymptotics at a
large time can be compactly written in terms of elementary functions that
depend on the roots of an Nth order characteristic polynomial. Our model can be
considered a generalization of the Demkov-Osherov model. In comparison to the
latter, our model allows one to explore the role of curvature of the band
levels and diabatic avoided crossings.

categories: quant-ph cond-mat.mes-hall math-ph math.MP


title: Uniform ergodicity of the Particle Gibbs sampler

abstract:
  The particle Gibbs (PG) sampler is a systematic way of using a particle
filter within Markov chain Monte Carlo (MCMC). This results in an off-the-shelf
Markov kernel on the space of state trajectories, which can be used to simulate
from the full joint smoothing distribution for a state space model in an MCMC
scheme. We show that the PG Markov kernel is uniformly ergodic under rather
general assumptions, that we will carefully review and discuss. In particular,
we provide an explicit rate of convergence which reveals that: (i) for fixed
number of data points, the convergence rate can be made arbitrarily good by
increasing the number of particles, and (ii) under general mixing assumptions,
the convergence rate can be kept constant by increasing the number of particles
superlinearly with the number of observations. We illustrate the applicability
of our result by studying in detail two common state space models with
non-compact state spaces.


title: Two-Page Book Embeddings of 4-Planar Graphs

abstract:
  Back in the Eighties, Heath showed that every 3-planar graph is
subhamiltonian and asked whether this result can be extended to a class of
graphs of degree greater than three. In this paper we affirmatively answer this
question for the class of 4-planar graphs. Our contribution consists of two
algorithms: The first one is limited to triconnected graphs, but runs in linear
time and uses existing methods for computing hamiltonian cycles in planar
graphs. The second one, which solves the general case of the problem, is a
quadratic-time algorithm based on the book-embedding viewpoint of the problem.


title:
The discharge characteristics of the DUHOCAMIS with a high magnetic
  bottle-shaped field

abstract:
  For the purpose to produce high intensity, multiply charged metal ion beams,
the DUHOCAMIS (dual hollow cathode ion source for metal ions) was derived from
the hot cathode Penning ion source combined with the hollow cathode sputtering
experiments in 2007. It was interesting to investigate the behavior of this
discharge geometry in a stronger magnetic bottle-shaped field. So a new test
bench for DUHOCAMIS with a high magnetic bottle-shaped field up to 0.6 T has
been set up at Peking University, on which have been made primary experiments
in connection with discharge characteristics of the source. The experiments
with magnetic fields from 0.13 T to 0.52 T have shown that the magnetic flux
densities are very sensitive to the discharge behavior: discharge curves and
ion spectra. It has been found that the slope of discharge curves in a very
wide range can be controlled by changing the magnetic field as well as
regulated by adjusting cathode heating power. On the other hand, by comparison
of discharge curves between dual hollow cathode discharge (DHCD) mode and PIG
discharge mode, it was found a much stronger magnetic effect occurred on DHCD
mode. In this paper, the new test bench with ion source structure is described
in detail; and main experimental results are presented and discussed, including
the effects of cathode heating power and magnetic flux density on discharge
characteristics, also the ion spectra. The effects of the magnetic field on the
source operating are emphasized, and a unique behavior of the DUHOCAMIS
operating in the high magnetic field is expected and discussed especially.


title: Bose-Fermi mixtures in the molecular limit

abstract:
  We consider a Bose-Fermi mixture in the molecular limit of the attractive
interaction between fermions and bosons. For a boson density smaller or equal
to the fermion density, we show analytically how a T-matrix approach for the
constituent bosons and fermions recovers the expected physical limit of a
Fermi-Fermi mixture of molecules and atoms. In this limit, we derive simple
expressions for the self-energies, the momentum distribution function, and the
chemical potentials. By extending these equations to a trapped system, we
determine how to tailor the experimental parameters of a Bose-Fermi mixture in
order to enhance the 'indirect Pauli exclusion effect' on the boson momentum
distribution function. For the homogeneous system, we present finally a
Diffusion Monte Carlo simulation which confirms the occurrence of such a
peculiar effect.


title:
Ricci Tensor for Diffusion Operators and Curvature-Dimension
  Inequalities under Conformal Transformations and Time Changes

abstract:
  Within the $\Gamma_2$-calculus of Bakry and Ledoux, we define the Ricci
tensor induced by a diffusion operator, we deduce precise formulas for its
behavior under drift transformation, time change and conformal transformation,
and we derive new transformation results for the curvature-dimension conditions
of Bakry-Emery as well as for those of Lott-Sturm-Villani. Our results are
based on new identities and sharp estimates for the $N$-Ricci tensor and for
the Hessian. In particular, we obtain Bochner's formula in the general setting.


title:
Quantile Regression for Location-Scale Time Series Models with
  Conditional Heteroscedasticity

abstract:
  This paper considers quantile regression for a wide class of time series
models including ARMA models with asymmetric GARCH (AGARCH) errors. The
classical mean-variance models are reinterpreted as conditional location-scale
models so that the quantile regression method can be naturally geared into the
considered models. The consistency and asymptotic normality of the quantile
regression estimator is established in location-scale time series models under
mild conditions. In the application of this result to ARMA-AGARCH models, more
primitive conditions are deduced to obtain the asymptotic properties. For
illustration, a simulation study and a real data analysis are provided.


title:
Machine Assisted Authentication of Paper Currency: an Experiment on
  Indian Banknotes

abstract:
  Automatic authentication of paper money has been targeted. Indian bank notes
are taken as reference to show how a system can be developed for discriminating
fake notes from genuine ones. Image processing and pattern recognition
techniques are used to design the overall approach. The ability of the embedded
security aspects is thoroughly analysed for detecting fake currencies. Real
forensic samples are involved in the experiment that shows a high precision
machine can be developed for authentication of paper money. The system
performance is reported in terms of both accuracy and processing speed.
Comparison with human subjects namely forensic experts and bank staffs clearly
shows its applicability for mass checking of currency notes in the real world.
The analysis of security features to protect counterfeiting highlights some
facts that should be taken care of in future designing of currency notes.


title: Tverberg plus constraints

abstract:
  Many of the strengthenings and extensions of the topological Tverberg theorem
can be derived with surprising ease directly from the original theorem: For
this we introduce a proof technique that combines a concept of "Tverberg
unavoidable subcomplexes" with the observation that Tverberg points that
equalize the distance from such a subcomplex can be obtained from maps to an
extended target space.
  Thus we obtain simple proofs for many variants of the topological Tverberg
theorem, such as the colored Tverberg theorem of Zivaljevic and Vrecica (1992).
We also get a new strengthened version of the generalized van Kampen-Flores
theorem by Sarkaria (1991) and Volovikov (1996), an affine version of their
"j-wise disjoint" Tverberg theorem, and a topological version of Soberon's
(2013) result on Tverberg points with equal barycentric coordinates.


title: Projective linear configurations via non-reductive actions

abstract:
  We study the iterated blow-up X of projective space along an arbitrary
collection of linear subspaces. By replacing the universal torsor with an
$\mathbb{A}^1$-homotopy equivalent model, built from $\mathbb{A}^1$-fiber
bundles not just algebraic line bundles, we construct an "algebraic
uniformization": X is a quotient of affine space by a solvable group action.
This provides a clean dictionary, using a single coordinate system, between the
algebra and geometry of hypersurfaces: effective divisors are characterized via
toric and invariant-theoretic techniques. In particular, the Cox ring is an
invariant subring of a Pic(X)-graded polynomial ring and it is an intersection
of two explicit finitely generated rings. When all linear subspaces are points,
this recovers a theorem of Mukai while also giving it a geometric proof and
topological intuition. Consequently, it is algorithmic to describe Cox(X) up to
any degree, and when Cox(X) is finitely generated it is algorithmic to verify
finite generation and compute an explicit presentation. We consider in detail
the special case of $\overline{M}_{0,n}$. Here the algebraic uniformization is
defined over the integers. It admits a natural modular interpretation, and it
yields a precise sense in which $\overline{M}_{0,n}$ is "one non-linearizable
$\mathbb{G}_a$ away" from being a toric variety. The Hu-Keel question becomes a
special case of Hilbert's 14th problem for $\mathbb{G}_a$.


title:
Percentage depth dose distributions in inhomogeneous phantoms with lung
  and bone equivalent media for small fields of CyberKnife

abstract:
  The percentage depth dose distributions in inhomogeneous phantoms with lung
and bone equivalent media are studied. For lung equivalent media a Balsa wood
is used, and for a soft bone equivalent media a compound material with epoxy
resin, hardener and calcium carbonate is used. Polystyrene slabs put together
with these materials are used as an inhomogeneous phantom. Dose measurements
are performed with Gafchromic EBT film by using photon beams from 6MV
CyberKnife at the Seoul Uridul Hospital. The cone sizes of the photon beams are
varied from 5, 10 to 30 mm. As a simulation tool GEANT4 Monte Carlo code
v9.4.p02 is used. When the Balsa wood is inserted in the phantom, the dose
measured with EBT film is found to be significantly different from the dose
without the EBT film in and beyond the Balsa wood region, particularly for
small field sizes. On the other hand, when the soft bone equivalent material is
inserted in the phantom, discrepancy between the dose measured with EBT film
and the dose without EBT film can be seen only in the region of bone equivalent
material. GEANT4 simulations are done with and without the EBT film to compare
the simulation results with measurements. We find that the simulations
including EBT film agree with the measurements for all the cases within an
error of $2.2\%$. Also, we find the "doses to phantom" without the EBT film
differ from the "doses to film" up to $29\%$, which shows that for accurate
dose estimations for inhomogeneous phantoms with EBT film the presence of the
EBT film needs to be taken into account properly in particular for small
fields.


title: Non-existence of greedy bases in direct sums of mixed $\ell_{p}$ spaces

abstract:
  The fact that finite direct sums of two or more mutually different spaces
from the family $\{\ell_{p} : 1\le p<\infty\}\cup c_{0}$ fail to have greedy
bases is stated in [Dilworth et al., Greedy bases for Besov spaces, Constr.
Approx. 34 (2011), no. 2, 281-296]. However, the concise proof that the authors
give of this fundamental result in greedy approximation relies on a fallacious
argument, namely the alleged uniqueness of unconditional basis up to
permutation of the spaces involved. The main goal of this note is to settle the
problem by providing a correct proof. For that we first show that all greedy
bases in an $\ell_{p}$ space have fundamental functions of the same order. As a
by-product of our work we obtain that every almost greedy basis of a Banach
space with unconditional basis and nontrivial type contains a greedy subbasis.


title:
Uncertainty-based information extraction in wireless sensor networks for
  control applications

abstract:
  Design of control applications over wireless sensor networks (WSNs) is a
challenging issue due to the bandwidth-limited communication medium, energy
constraints and real-time data delivery requirements. This paper introduces a
new information extraction method for WSN-based control applications, which
reduces the number of required data transmissions to save energy and avoid data
congestion. According to the proposed approach, control applications recognize
when new data readings have to be collected and determine sensor nodes that
have to be activated on the basis of uncertainty analysis. Processing of the
selectively collected input data is based on definition of information granules
that describe state of the controlled system as well as performance of
particular control decisions. This method was implemented for object tracking
in WSNs. The task is to control movement of a mobile sink, which has to reach a
target in the shortest possible time. Extensive simulation experiments were
performed to compare performance of the proposed approach against
state-of-the-art methods. Results of the experiments show that the presented
information extraction method allows for substantial reduction in the amount of
transmitted data with no significant negative effect on tracking performance.


title: Mapping multiplicative to additive noise

abstract:
  The Langevin formulation of a number of well-known stochastic processes
involves multiplicative noise. In this work we present a systematic mapping of
a process with multiplicative noise to a related process with additive noise,
which may often be easier to analyse. The mapping is easily understood in the
example of the branching process. In a second example we study the random
neighbour (or infinite range) contact process which is mapped to an
Ornstein-Uhlenbeck process with absorbing wall. The present work might shed
some light on absorbing state phase transitions in general, such as the role of
conditional expectation values and finite size scaling, and elucidate the
meaning of the noise amplitude. While we focus on the physical interpretation
of the mapping, we also provide a mathematical derivation.


title: Simulating the initial growth of a deposit from colloidal suspensions

abstract:
  We study the short time properties of a two-dimensional film growth model in
which incident particles execute advective-diffusive motion with a vertical
step followed by $D$ horizontal steps. The model represents some features of
the deposition of anisotropic colloidal particles of the experiment in Phys.
Rev. Lett. {\bf 110}, 035501 (2013), in which wandering particles are attracted
to particle-rich regions in the deposit. Height profiles changing from rough to
columnar structure are observed as $D$ increases from $0$ (ballistic
deposition) to $8$, with striking similarity to the experimental ones. The
effective growth exponents matches the experimental estimates and the scaling
of those exponents on $D$ show a remarkable effect of the range of the
particle-deposit interaction. The nearly ellipsoidal shape of colloidal
particles is represented for the calculation of roughness exponents in
conditions that parallel the experimental ones, giving a range of estimates
that also include the experimental values. The effective dynamic exponents
calculated from the autocorrelation function are shown to be suitable to decide
between a true dynamic scaling or transient behavior, particularly because the
latter leads to deviations in an exponent relation. These results are
consistent with arguments on short time unstable (columnar) growth of Phys.
Rev. Lett {\bf 111}, 209601 (2013), indicating that critical quenched KPZ
dynamics does not explain that colloidal particle deposition problem.


title:
Time series analysis of Parkinson's disease, Huntington's disease and
  Amyotrophic Lateral Sclerosis

abstract:
  The aim of this paper is to study the (clinical) time-series data of three
diseases with complex dynamics: Parkinson's disease, Huntington's disease and
Amyotrophic Lateral Sclerosis. For this purpose, first all of the time series
data are embedded in a vector space of suitable dimension and then the
correlation dimension of the above mentioned diseases is estimated. The results
are also compared with healthy control subjects. At the next step, existence of
chaos in these diseases is investigated by means of the so-called 0-1 test. The
simulations show that none of the above mentioned diseases are chaotic.


title: A New Possible Way to Explain the DAMA Results

abstract:
  At present there is an effort to reconcile the results of the DAMA experiment
with those from other Dark Matter experiments such as CoGeNT, CRESST, CDMS, and
all LXe experiments. The author suggests a new model describing the Dark Matter
signal as the result of collisions of very light (1-to-few GeV/c^2) WIMPs with
hydrogen, and compares it with currently accepted models of collisions with
heavy nuclei (Na, Ge or Xe). The hydrogen target would come from
H-contamination of NaI(Tl), Ge and CaWO4 crystals. Initial tuning indicates
that one can explain the modulation amplitude of DAMA and CoGeNT with this
model, assuming a WIMP-proton cross section between 10^33 and 10^32 cm^2. This
paper should be considered to be a new idea which will need substantial new
experimental input from all involved experiments.


title: Nonuniform Graph Partitioning with Unrelated Weights

abstract:
  We give a bi-criteria approximation algorithm for the Minimum Nonuniform
Partitioning problem, recently introduced by Krauthgamer, Naor, Schwartz and
Talwar (2014). In this problem, we are given a graph $G=(V,E)$ on $n$ vertices
and $k$ numbers $\rho_1,\dots, \rho_k$. The goal is to partition the graph into
$k$ disjoint sets $P_1,\dots, P_k$ satisfying $|P_i|\leq \rho_i n$ so as to
minimize the number of edges cut by the partition. Our algorithm has an
approximation ratio of $O(\sqrt{\log n \log k})$ for general graphs, and an
$O(1)$ approximation for graphs with excluded minors. This is an improvement
upon the $O(\log n)$ algorithm of Krauthgamer, Naor, Schwartz and Talwar
(2014). Our approximation ratio matches the best known ratio for the Minimum
(Uniform) $k$-Partitioning problem.
  We extend our results to the case of "unrelated weights" and to the case of
"unrelated $d$-dimensional weights". In the former case, different vertices may
have different weights and the weight of a vertex may depend on the set $P_i$
the vertex is assigned to. In the latter case, each vertex $u$ has a
$d$-dimensional weight $r(u,i) = (r_1(u,i), \dots, r_d(u,i))$ if $u$ is
assigned to $P_i$. Each set $P_i$ has a $d$-dimensional capacity $c(i) =
(c_1(i),\dots, c_d(i))$. The goal is to find a partition such that $\sum_{u\in
{P_i}} r(u,i) \leq c(i)$ coordinate-wise.


title: Finite-dimensional simple modules over generalized Heisenberg algebras

abstract:
  Generalized Heisenberg algebras $\H(f)$ for any polynomial $f(h)\in\C[h]$
have been used to explain various physical systems and many physical phenomena
for the last 20 years. In this paper, we first obtain the center of $\H(f)$,
and the necessary and sufficient conditions on $f$ for two $\H(f)$ to be
isomorphic. Then we determine all finite dimensional simple modules over
$\H(f)$ for any polynomial $f(h)\in\C[h]$. If $f=wh+c$ for any $c\in \C$ and
$n$-th ($n>1$) primitive root $w$ of unity we actually obtain a complete
classification of all irreducible modules over $\mathcal{H}(f)$. For many
$f\in\C[h]$, we also prove that, for any $n\in\N$, $\mathcal{H}(f)$ has
infinitely many ideals $I_n$ such that $\mathcal{H}(f)/I_n\cong M_n(\C)$, the
matrix algebra.


title:
Nonequilibrium quantum fluctuations of a dispersive medium: Spontaneous
  emission, photon statistics, entropy generation, and stochastic motion

abstract:
  We study the implications of quantum fluctuations of a dispersive medium,
under steady rotation, either in or out of thermal equilibrium with its
environment. A rotating object exhibits a quantum instability by dissipating
its mechanical motion via spontaneous emission of photons, as well as internal
heat generation. Universal relations are derived for the radiated energy and
angular momentum as trace formulas involving the object's scattering matrix. We
also compute the quantum noise by deriving the full statistics of the radiated
photons out of thermal and/or dynamic equilibrium. The (entanglement) entropy
generation is quantified, and the total entropy is shown to be always
increasing. Furthermore, we derive a Fokker-Planck equation governing the
stochastic angular motion resulting from the fluctuating back-reaction
frictional torque. As a result, we find a quantum limit on the uncertainty of
the object's angular velocity in steady rotation. Finally, we show in some
detail that a rotating object drags nearby objects, making them spin parallel
to its axis of rotation. A scalar toy model is introduced in the first part to
simplify the technicalities and ease the conceptual complexities; a detailed
discussion of quantum electrodynamics is presented in the second part.


title:
A Parallel Space Saving Algorithm For Frequent Items and the Hurwitz
  zeta distribution

abstract:
  We present a message-passing based parallel version of the Space Saving
algorithm designed to solve the $k$--majority problem. The algorithm determines
in parallel frequent items, i.e., those whose frequency is greater than a given
threshold, and is therefore useful for iceberg queries and many other different
contexts. We apply our algorithm to the detection of frequent items in both
real and synthetic datasets whose probability distribution functions are a
Hurwitz and a Zipf distribution respectively. Also, we compare its parallel
performances and accuracy against a parallel algorithm recently proposed for
merging summaries derived by the Space Saving or Frequent algorithms.


title:
Electronic structure and magnetic properties of Mn and Fe impurities
  near GaAs (110) surface

abstract:
  Combining density-functional theory calculations and microscopic
tight-binding models, we investigate theoretically the electronic and magnetic
properties of individual substitutional transition-metal impurities (Mn and Fe)
positioned in the vicinity of the (110) surface of GaAs. For the case of the
$[\rm Mn^{2+}]^0$ plus acceptor-hole (h) complex, the results of a
tight-binding model including explicitly the impurity $d$-electrons are in good
agreement with approaches that treat the spin of the impurity as an effective
classical vector. For the case of Fe, where both the neutral isoelectronic
$[\rm Fe^{3+}]^0$ and the ionized $[\rm Fe^{2+}]^-$ states are relevant to
address scanning tunneling microscopy (STM) experiments, the inclusion of
$d$-orbitals is essential. We find that the in-gap electronic structure of Fe
impurities is significantly modified by surface effects. For the neutral
acceptor state $[{\rm Fe}^{2+}, h]^0$, the magnetic-anisotropy dependence on
the impurity sublayer resembles the case of $[{\rm Mn}^{2+}, h]^0$. In
contrast, for $[{\rm Fe}^{3+}]^{0}$ electronic configuration the magnetic
anisotropy behaves differently and it is considerably smaller. For this state
we predict that it is possible to manipulate the Fe moment, e.g. by an external
magnetic field, with detectable consequences in the local density of states
probed by STM.


title: A combinatorial approach to products of Pisot substitutions

abstract:
  We define a generic algorithmic framework to prove pure discrete spectrum for
the substitutive symbolic dynamical systems associated with some infinite
families of Pisot substitutions. We focus on the families obtained as finite
products of the three-letter substitutions associated with the multidimensional
continued fraction algorithms of Brun and Jacobi-Perron.
  Our tools consist in a reformulation of some combinatorial criteria
(coincidence conditions), in terms of properties of discrete plane generation
using multidimensional (dual) substitutions. We also deduce some topological
and dynamical properties of the Rauzy fractals, of the underlying symbolic
dynamical systems, as well as some number-theoretical properties of the
associated Pisot numbers.


title: Undecidable properties of self-affine sets and multi-tape automata

abstract:
  We study the decidability of the topological properties of some objects
coming from fractal geometry. We prove that having empty interior is
undecidable for the sets defined by two-dimensional graph-directed iterated
function systems. These results are obtained by studying a particular class of
self-affine sets associated with multi-tape automata. We first establish the
undecidability of some language-theoretical properties of such automata, which
then translate into undecidability results about their associated self-affine
sets.


title:
A clear and measurable signature of modified gravity in the galaxy
  velocity field

abstract:
  The velocity field of dark matter and galaxies reflects the continued action
of gravity throughout cosmic history. We show that the low-order moments of the
pairwise velocity distribution, $v_{12}$, are a powerful diagnostic of the laws
of gravity on cosmological scales. In particular, the projected line-of-sight
galaxy pairwise velocity dispersion, $\sigma_{12}(r)$, is very sensitive to the
presence of modified gravity. Using a set of high-resolution N-body simulations
we compute the pairwise velocity distribution and its projected line-of-sight
dispersion for a class of modified gravity theories: the chameleon \fR gravity
and Galileon gravity (cubic and quartic). The velocities of dark matter halos
with a wide range of masses would exhibit deviations from General Relativity at
the $(5-10)\sigma$ level. We examine strategies for detecting these deviations
in galaxy redshift and peculiar velocity surveys. If detected, this signature
would be a "smoking gun" for modified gravity.


title:
The XMM-Newton view of the yellow hypergiant IRC +10420 and its
  surroundings

abstract:
  Among evolved massive stars likely in transition to the Wolf-Rayet phase, IRC
+10420 is probably one of the most enigmatic. It belongs to the category of
yellow hypergiants and it is characterized by quite high mass loss episodes.
Even though IRC +10420 benefited of many observations in several wavelength
domains, it has never been a target for an X-ray observatory. We report here on
the very first dedicated observation of IRC +10420 in X-rays, using the
XMM-Newton satellite. Even though the target is not detected, we derive X-ray
flux upper limits of the order of 1--3 10^-14 erg cm^-2 s^-1 (between 0.3 and
10.0 keV), and we discuss the case of IRC +10420 in the framework of emission
models likely to be adequate for such an object. Using the Optical/UV Monitor
on board XMM-Newton, we present the very first upper limits of the flux density
of IRC +10420 in the UV domain (between 1800 and 2250 A, and between 2050 and
2450 A). Finally, we also report on the detection in this field of 10 X-ray and
7 UV point sources, and we briefly discuss their properties and potential
counterparts at longer wavelengths.


title:
Quantitative methods for Phylogenetic Inference in Historical
  Linguistics: An experimental case study of South Central Dravidian

abstract:
  In this paper we examine the usefulness of two classes of algorithms Distance
Methods, Discrete Character Methods (Felsenstein and Felsenstein 2003) widely
used in genetics, for predicting the family relationships among a set of
related languages and therefore, diachronic language change. Applying these
algorithms to the data on the numbers of shared cognates- with-change and
changed as well as unchanged cognates for a group of six languages belonging to
a Dravidian language sub-family given in Krishnamurti et al. (1983), we
observed that the resultant phylogenetic trees are largely in agreement with
the linguistic family tree constructed using the comparative method of
reconstruction with only a few minor differences. Furthermore, we studied these
minor differences and found that they were cases of genuine ambiguity even for
a well-trained historical linguist. We evaluated the trees obtained through our
experiments using a well-defined criterion and report the results here. We
finally conclude that quantitative methods like the ones we examined are quite
useful in predicting family relationships among languages. In addition, we
conclude that a modest degree of confidence attached to the intuition that
there could indeed exist a parallelism between the processes of linguistic and
genetic change is not totally misplaced.


title: Axion-Electromagnetic Waves

abstract:
  We extend the duality symmetry between the electric and the magnetic fields
to the case in which an additional axion-like term is present, and we derive
the set of Maxwell's equations that preserves this symmetry. This new set of
equations allows for a gauge symmetry extending the ordinary symmetry in the
classical electrodynamics. We obtain explicit solutions for the new set of
equations in the absence of external sources, and we discuss the implications
of a new internal symmetry between the axion field and the electromagnetic
gauge potential.


title:
GeMS in the Outer Galaxy: Near-Infrared Imaging of Three Young Clusters
  at Large Galactic Radii

abstract:
  Images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and
corrected for atmospheric seeing by the Gemini Multiconjugate Adaptive Optics
System (GeMS) are used to investigate the stellar contents of the young outer
Galactic disk clusters Haffner 17, NGC 2401, and NGC 3105. Ages estimated from
the faint end of the main sequence (MS) and the ridgeline of the pre-main
sequence (PMS) on the (K, J-K) color-magnitude diagrams are consistent with
published values that are based on the MS turn-off, with the GSAOI data
favoring the younger end of the age range for NGC 2401 in the literature. The
mass function (MF) of NGC 2401 is similar to that in the Solar neighborhood,
and stars spanning a wide range of masses in this cluster have similar
clustering properties on the sky. It is concluded that NGC 2401 is not evolved
dynamically. In contrast, the MF of Haffner 17 differs significantly from that
in the Solar neighborhood over all masses covered by these data, while the MF
of NGC 3105 is deficient in objects with sub-solar masses when compared with
the Solar neighborhood. Low mass objects in Haffner 17 and NGC 3105 are also
more uniformly distributed on the sky than brighter, more massive, MS stars.
This is consistent with both clusters having experienced significant dynamical
evolution.


title:
Computing Entropy Rate Of Symbol Sources & A Distribution-free Limit
  Theorem

abstract:
  Entropy rate of sequential data-streams naturally quantifies the complexity
of the generative process. Thus entropy rate fluctuations could be used as a
tool to recognize dynamical perturbations in signal sources, and could
potentially be carried out without explicit background noise characterization.
However, state of the art algorithms to estimate the entropy rate have markedly
slow convergence; making such entropic approaches non-viable in practice. We
present here a fundamentally new approach to estimate entropy rates, which is
demonstrated to converge significantly faster in terms of input data lengths,
and is shown to be effective in diverse applications ranging from the
estimation of the entropy rate of English texts to the estimation of complexity
of chaotic dynamical systems. Additionally, the convergence rate of entropy
estimates do not follow from any standard limit theorem, and reported
algorithms fail to provide any confidence bounds on the computed values.
Exploiting a connection to the theory of probabilistic automata, we establish a
convergence rate of $O(\log \vert s \vert/\sqrt[3]{\vert s \vert})$ as a
function of the input length $\vert s \vert$, which then yields explicit
uncertainty estimates, as well as required data lengths to satisfy
pre-specified confidence bounds.

categories: cs.IT cs.LG math.IT math.PR stat.CO stat.ML


title:
Charge-density-wave order with momentum $(2Q, 0)$ and $(0, 2Q)$ within
  the spin-fermion model: continuous and discrete symmetry breaking, preemptive
  composite order, and relation to pseudogap in hole-doped cuprates

abstract:
  We analyze charge order within the the spin-fermion model. We show that
magnetically-mediated interaction gives rise to charge order $\Delta_k^Q =
\langle c^\dagger_{{\bf k}+{\bf Q}} c_{{\bf k}-{\bf Q}}\rangle$ with momenta
${\bf Q}=Q_x =(2Q,0)$ and ${\bf Q}=Q_y =(0,2Q)$, if the magnetic correlation
length $\xi$ exceeds some critical value. We argue that $\Delta_k^Q$ and
$\Delta_{-k}^Q$ are not equivalent, and their symmetric and antisymmetric
combinations describe density modulations and bond current. We derive GL
functional for four-component $U(1)$ order parameters $\Delta^Q_{\pm k}$ with
${\bf Q} = Q_x$ or $Q_y$. Within mean-field we find two types of CDW states, I
and II, depending on system parameters. In state I density and current
modulations emerge with the same ${\bf Q} = Q_x$ or $Q_y$, breaking $Z_2$
lattice rotational symmetry, and differ in phase by $\pm\pi/2$. The selection
of $\pi/2$ or $-\pi/2$ additionally breaks $Z_2$ time-reversal symmetry, such
that the total order parameter manifold is $U(1) \times Z_2 \times Z_2$. In
state II density and current modulations emerge with different $\bf Q$ and the
order parameter manifold is $U(1) \times U (1) \times Z_2$. We go beyond
mean-field and show that discrete symmetries get broken before long-range
charge order sets in. For state I, the system first breaks $Z_2$ lattice
rotational symmetry ($C_4 \to C_2$) at $T= T_n$ and develops a nematic order,
then breaks $Z_2$ time-reversal symmetry at $T_t < T_n$, and finally breaks
$U(1)$ symmetry of a common phase of even and odd components of $\Delta^Q_{k}$
at $T= T_{\rm cdw} < T_t < T_n$ and develops a true charge order. We argue that
the preemptive orders lift $T_{\rm cdw}$ and reduces $T_{\rm sc}$ such that at
large $\xi$ charge order may develop prior to superconductivity. We obtain the
phase diagram and present quantitative comparison with ARPES data for
hole-doped cuprates.


title: Gluonic three-point correlations in pure Landau gauge QCD

abstract:
  We report on the first self-consistent solution of the Dyson-Schwinger
equation (DSE) for the three-gluon vertex. Based on earlier results for the
propagators which match data from lattice Monte-Carlo simulations, we obtain
results for the three-gluon vertex that are in very good agreement with
available lattice data likewise. Feeding these results back into the propagator
DSEs leads to some changes especially in the gluon propagator. These changes
allow us to assess previously used models for the three-gluon vertex and to
systematically estimate the influence of neglected two-loop diagrams with
four-gluon interactions. In the final step, a full iterative solution to the
coupled DSEs of pure Landau gauge QCD without quarks is then obtained for the
first time in an extended truncation which now dynamically includes the
complete set of three-point vertex functions.


title: Cold, ultracold and Nariai black holes with quintessence

abstract:
  In this paper, we study the properties of the charged black hole surrounded
by the quintessence. The solution space for the horizons for various values of
the mass $M$, charge $Q$, and the quintessence parameter $\alpha$ are studied
in detail. Special focus in given to the degenerate horizons: we obtain cold,
ultracold and Nariai black holes which has similar topologies as for the
Reissner-Nordstrom-de Sitter black holes. We also study the lukewarm black hole
with the quintessence in this paper.


title: A Note on Minimal zero-sum sequences over ${\mathbb Z}$

abstract:
  A zero-sum sequence over ${\mathbb Z}$ is a sequence with terms in ${\mathbb
Z}$ that sum to $0$. It is called minimal if it does not contain a proper
zero-sum subsequence. Consider a minimal zero-sum sequence over ${\mathbb Z}$
with positive terms $a_1,\ldots,a_h$ and negative terms $b_1,\ldots,b_k$. We
prove that $h\leq \lfloor \sigma^+/k\rfloor$ and $k\leq \lfloor
\sigma^+/h\rfloor$, where $\sigma^+=\sum_{i=1}^h a_i=-\sum_{j=1}^k b_j$. These
bounds are tight and improve upon previous results. We also show a natural
partial order structure on the collection of all minimal zero-sum sequences
over the set $\{i\in {\mathbb Z}:\; -n\leq i\leq n\}$ for any positive integer
$n$.


title: Radio Astronomy in LSST Era

abstract:
  A community meeting on the topic of "Radio Astronomy in the LSST Era" was
hosted by the National Radio Astronomy Observatory in Charlottesville, VA (2013
May 6--8). The focus of the workshop was on time domain radio astronomy and sky
surveys. For the time domain, the extent to which radio and visible wavelength
observations are required to understand several classes of transients was
stressed, but there are also classes of radio transients for which no visible
wavelength counterpart is yet known, providing an opportunity for discovery.
From the LSST perspective, the LSST is expected to generate as many as 1
million alerts nightly, which will require even more selective specification
and identification of the classes and characteristics of transients that can
warrant follow up, at radio or any wavelength. The LSST will also conduct a
deep survey of the sky, producing a catalog expected to contain over 38 billion
objects in it. Deep radio wavelength sky surveys will also be conducted on a
comparable time scale, and radio and visible wavelength observations are part
of the multi-wavelength approach needed to classify and understand these
objects. Radio wavelengths are valuable because they are unaffected by dust
obscuration and, for galaxies, contain contributions both from star formation
and from active galactic nuclei. The workshop touched on several other topics,
on which there was consensus including the placement of other LSST "Deep
Drilling Fields," inter-operability of software tools, and the challenge of
filtering and exploiting the LSST data stream. There were also topics for which
there was insufficient time for full discussion or for which no consensus was
reached, which included the procedures for following up on LSST observations
and the nature for future support of researchers desiring to use LSST data
products.

categories: astro-ph.IM astro-ph.CO astro-ph.GA astro-ph.HE astro-ph.SR


title:
Cosmological parameter estimation from CMB and X-ray clusters after
  Planck

abstract:
  We update the cosmological parameter estimation for three non-vanilla models
by a joint analysis of \CCCP\ X-ray cluster, the newly released \Planck\ CMB
data as well as some external data sets, such as baryon acoustic oscillation
measurements from the 6dFGS, SDSS DR7 and BOSS DR9 surveys, and Hubble Space
Telescope $H_0$ measurement. First of all, we find that X-ray cluster data sets
strongly favor a non-zero summed neutrino mass at more than 3$\sigma$
confidence level in these non-vanilla models. And then, we reveal some tensions
between X-ray cluster and {\it Planck} data in some cosmological parameters.
For the matter power spectrum amplitude $\sigma_8$, X-ray cluster data favor a
lower value compared with {\it Planck}. Because of the strong $\sigma_8-\sum
m_{\nu}$ degeneracy, this tension could beyond 2$\sigma$ confidence level when
the summed neutrino mass $\sum m_{\nu}$ is allowed to vary. For the CMB lensing
amplitude $A_L$, the addition of X-ray cluster data results in a 3$\sigma$
deviation from the vanilla model. Furthermore, {\it Planck}+X-ray data prefer a
large Hubble constant and phantom-like dark energy equation of state, which are
in $2\sigma$ tension with those from WMAP7+X-ray data. Finally, we find that
these tensions/descrepencies could be relaxed in some sense by adding a $9\%$
systematic shift in the cluster mass functions.


title:
Generalization of the Poisson distribution for the case of changing
  probabilities of consecutive events

abstract:
  In this paper the generalization of the Poisson distribution is derived for
the case when each consecutive event changes event rate. A simple formula for
the probability of observing of a given number of events for the selected
period of time is derived for a given set of rates. Application of this
distribution in high-energy physics calculations is discussed.


title:
Linearly Degenerate Hamiltonian PDEs and a New Class of Solutions to the
  WDVV Associativity Equations

abstract:
  We define a new class of solutions to the WDVV associativity equations. This
class is determined by the property that one of the commuting PDEs associated
with such a WDVV solution is linearly degenerate. We reduce the problem of
classifying such solutions of the WDVV equations to the particular case of the
so-called algebraic Riccati equation and, in this way, arrive at a complete
classification of irreducible solutions.


title:
Water Cycling Between Ocean and Mantle: Super-Earths Need Not be
  Waterworlds

abstract:
  Large terrestrial planets are expected to have muted topography and deep
oceans, implying that most super-Earths should be entirely covered in water,
so-called waterworlds. This is important because waterworlds lack a silicate
weathering thermostat so their climate is predicted to be less stable than that
of planets with exposed continents. In other words, the continuously habitable
zone for waterworlds is much narrower than for Earth-like planets. A planet's
water is partitioned, however, between a surface reservoir, the ocean, and an
interior reservoir, the mantle. Plate tectonics transports water between these
reservoirs on geological timescales. Degassing of melt at mid-ocean ridges and
serpentinization of oceanic crust depend negatively and positively on seafloor
pressure, respectively, providing a stabilizing feedback on long-term ocean
volume. Motivated by Earth's approximately steady-state deep water cycle, we
develop a two-box model of the hydrosphere and derive steady-state solutions to
the water partitioning on terrestrial planets. Critically, hydrostatic seafloor
pressure is proportional to surface gravity, so super-Earths with a deep water
cycle will tend to store more water in the mantle. We conclude that a
tectonically active terrestrial planet of any mass can maintain exposed
continents if its water mass fraction is less than ~0.2%, dramatically
increasing the odds that super-Earths are habitable. The greatest source of
uncertainty in our study is Earth's current mantle water inventory: the greater
its value, the more robust planets are to inundation. Lastly, we discuss how
future missions can test our hypothesis by mapping the oceans and continents of
massive terrestrial planets.


title:
\"Uber erreichbare und baumartige unzerlegbare Darstellungen von
  K\"ochern

abstract:
  Let $A$ be a finite-dimensional algebra over an algebraically closed field.
The problem of constructing indecomposable $A$-modules inductively from simple
ones by means of exact sequences - called accessibility - is the starting point
of the present diploma-thesis. It has lead us to the consideration of
exceptional and indecomposable tree-representations of finite quivers.
Following Ringel, we prove his result that exceptional representations are
tree-representations. We give a detailed description of the various aspects of
the Schofield-Induction which plays an important role in the proof. Moreover we
introduce a functor (strong hypotheses being given) which enables us to
construct indecomposable modules of an algebra from indecomposable
representations of a certain bipartite quiver. We also give a proof of Ringel's
result that each exceptional representation of dimension $d>1$ of a generalized
Kronecker quiver has an indecomposable factor- or subrepresentation of
dimension $d-1$. The thesis is concluded by some calculations showing the
accessibility of representations of the 3-Kronecker-quiver in small dimensions.


title:
The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9m
  Program: Trigonometric Parallaxes of Nearby Low-Mass Active and Young Systems

abstract:
  We present basic observational data and association membership analysis for
45 young and active low-mass stellar systems from the ongoing RECONS photometry
and astrometry program at the Cerro Tololo Inter-American Observatory. Most of
these systems have saturated X-ray emission (log(Lx/Lbol) > -3.5) based on
X-ray fluxes from the ROSAT All-Sky Survey, and many are significantly more
luminous than main-sequence stars of comparable color. We present parallaxes
and proper motions, Johnson-Kron-Cousins VRI photometry, and multiplicity
observations from the CTIOPI program on the CTIO 0.9m telescope. To this we add
low-resolution optical spectroscopy and line measurements from the CTIO 1.5m
telescope, and interferometric binary measurements from the Hubble Space
Telescope Fine Guidance Sensors. We also incorporate data from published
sources: JHKs photometry from the 2MASS point source catalog; X-ray data from
the ROSAT All-Sky Survey; and radial velocities from literature sources. Within
the sample of 45 systems, we identify 21 candidate low-mass pre-main-sequence
members of nearby associations, including members of beta Pictoris, TW Hydrae,
Argus, AB Doradus, two ambiguous 30 Myr old systems, and one object that may be
a member of the Ursa Major moving group. Of the 21 candidate young systems, 14
are newly identified as a result of this work, and six of those are within 25
parsecs of the Sun.


title:
Spin-Transfer-Torque Driven Magneto-Logic Gates Using Nano Spin-Valve
  Pillars

abstract:
  We propose model magneto-logic NOR and NAND gates using a spin valve pillar,
wherein the logical operation is induced by spin-polarized currents which also
form the logical inputs. The operation is facilitated by the simultaneous
presence of a constant controlling magnetic field. The same spin-valve assembly
can also be used as a magnetic memory unit. We identify regions in the
parameter space of the system where the logical operations can be effectively
performed. The proposed gates retain the non-volatility of a magnetic random
access memory,(MRAM). We verify the functioning of the gate by numerically
simulating its dynamics, governed by the appropriate Landau-Lifshitz-Gilbert
equation with the spin-transfer torque term. The flipping time for the logical
states is estimated to be within nano seconds.


title:
The Cosmological Constant Constrained with Union2.1 Supernovae Type Ia
  Data. Derivation and evaluation of several FRW and Carmeli models presenting
  underwhelming support for the standard model

abstract:
  We derive several, detailed relationships in terms of the Friedmann,
Robertson, Walker (FRW) generalization which describe the Universe during both
the radiation and matter dominated epochs. We explicitly provide for the
influence of radiation, rather than burying this term within the matter term.
Several models allow the cosmological constant (CC) to vary with universe
expansion in differing manners. We evaluate these and other popular models
including the $\Lambda$CDM({standard model}), quintessence as presented by
Vishwakarma, Equation of State (EoS) and the Carmeli model with data from the
580 Union2.1 supernovae type Ia collection, using several minimization routines
and find models built about the CC, the $\Lambda$CDM models, fare no better
than those without.


title:
Single-photon frequency conversion and multi-mode entanglement via
  constructive interference on Sagnac Loop

abstract:
  Based on constructive interference in Sagnac waveguide loop, an efficient
scheme is proposed for selective frequency conversion and multifrequency modes
W entanglement via input-output formalism. We can adjust the probability
amplitudes of output photons by choosing parameter values properly. The tunable
probability amplitude will lead to the generation of output photon with a
selectable frequency and W photonic entanglement of different frequencies modes
in a wide range of parameter values. Our calculations show the present scheme
is robust to the deviation of parameters and spontaneous decay.


title:
The Dark Matter distribution function and Halo Thermalization from the
  Eddington equation in Galaxies

abstract:
  We find the distribution function f(E) for dark matter (DM) halos in galaxies
and the corresponding equation of state from the (empirical) DM density
profiles derived from observations. We solve for DM in galaxies the analogous
of the Eddington equation originally used for the gas of stars in globular
clusters. The observed density profiles are a good realistic starting point and
the distribution functions derived from them are realistic. We do not make any
assumption about the DM nature, the methods developed here apply to any DM
kind, though all results are consistent with Warm DM. With these methods we
find: (i) Cored density profiles behaving quadratically for small distances
rho(r) r -> 0 = rho(0) - K r^2 produce distribution functions which are finite
and positive at the halo center while cusped density profiles always produce
divergent distribution functions at the center. (ii) Cored density profiles
produce approximate thermal Boltzmann distribution functions for r < 3 r_h
where r_h is the halo radius. (iii) Analytic expressions for the dispersion
velocity and the pressure are derived yielding an ideal DM gas equation of
state with local temperature T(r) = m v^2(r)/3. T(r) turns to be constant in
the same region where the distribution function is thermal and exhibits the
same temperature within the percent. The self-gravitating DM gas can thermalize
despite being collisionless because it is an ergodic system. (iv) The DM halo
can be consistently considered at local thermal equilibrium with: (a) a
constant temperature T(r) = T_0 for r < 3 \; r_h, (b) a space dependent
temperature T(r) for 3 r_h < r < R_{virial}, which slowly decreases with r.
That is, the DM halo is realistically a collisionless self-gravitating thermal
gas for r < R_{virial}. (v) T(r) outside the halo radius nicely follows the
decrease of the circular velocity squared.


title: Disorder-tuned selection of order in bilayer graphene

abstract:
  The nature of the interaction-driven spontaneously broken-symmetry state in
charge neutral bilayer graphene (BLG) has attracted a lot of interest.
Theoretical studies predict various ordered states as the candidates for the
ground state of BLG in the absence of external fields. Several experiments have
been performed by different groups to identify the nature of the collective
ground state in BLG. However, so far, there is no consensus: some experiments
show evidence that suggests the establishment of a nematic gapless state, while
others present results that are more consistent with the establishment of a
fully gapped state. Moreover, even among the experiments that appear to see a
bulk gap, some of the samples are found to be conducting (suggesting existence
of gapless edge states), while others are insulating. Here we explore the
hypothesis that disorder might explain the discrepancy between experiments. We
find that the pair breaking effect due to non-magnetic short-range disorder
varies among the candidate ground states, giving rise to different amounts of
suppression of their mean-field transition temperatures. Our results indicate
that BLG can undergo a transition between different ordered states as a
function of the disorder strength providing a possible scenario to resolve the
discrepancy between experimental observations.


title:
Spitzer Space Telescope spectra of post-AGB stars in the Large
  Magellanic Cloud ---polycyclic aromatic hydrocarbons at low metallicities

abstract:
  This paper reports variations of polycyclic aromatic hydrocarbons (PAHs)
features that were found in Spitzer Space Telescope spectra of carbon-rich
post-asymptotic giant branch (post-AGB) stars in the Large Magellanic Cloud
(LMC). The paper consists of two parts. The first part describes our Spitzer
spectral observing programme of 24 stars including post-AGB candidates. The
latter half of this paper presents the analysis of PAH features in 20
carbon-rich post-AGB stars in the LMC, assembled from the Spitzer archive as
well as from our own programme. We found that five post-AGB stars showed a
broad feature with a peak at 7.7 micron, that had not been classified before.
Further, the 10--13 micron PAH spectra were classified into four classes, one
of which has three broad peaks at 11.3, 12.3 and 13.3 micron rather than two
distinct sharp peaks at 11.3 and 12.7 micron, as commonly found in HII regions.
Our studies suggest that PAHs are gradually processed while the central stars
evolve from post-AGB phase to PNe, changing their composition before PAHs are
incorporated into the interstellar medium. Although some metallicity dependence
of PAH spectra exists, the evolutionary state of an object is more significant
than its metallicity in determining the spectral characteristics of PAHs for
LMC and Galactic post-AGB stars.


title: The Host Galaxies of Fast-Ejecta Core-Collapse Supernovae

abstract:
  Spectra of broad-lined Type Ic supernovae (SN Ic-BL), the only kind of SN
observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit
wide features indicative of high ejecta velocities (~0.1c). We study the host
galaxies of a sample of 245 low-redshift (z<0.2) core-collapse SN, including 17
SN Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous
and dust-obscured z<1.2 LGRBs. We show that, in comparison with SDSS galaxies
having similar stellar masses, the hosts of low-redshift SN Ic-BL and z<1.2
LGRBs have high stellar-mass and star-formation-rate densities. Core-collapse
SN having typical ejecta velocities, in contrast, show no preference for such
galaxies. Moreover, we find that the hosts of SN Ic-BL, unlike those of SN
Ib/Ic and SN II, exhibit high gas velocity dispersions for their stellar
masses. The patterns likely reflect variations among star-forming environments,
and suggest that LGRBs can be used as probes of conditions in high-redshift
galaxies. They may be caused by efficient formation of massive binary
progenitors systems in densely star-forming regions, or, less probably, a
higher fraction of stars created with the initial masses required for a SN
Ic-BL or LGRB. Finally, we show that the preference of SN Ic-BL and LGRBs for
galaxies with high stellar-mass and star-formation-rate densities cannot be
attributed to a preference for low metal abundances but must reflect the
influence of a separate environmental factor.


title:
What is usual in unusual videos? Trajectory snippet histograms for
  discovering unusualness

abstract:
  Unusual events are important as being possible indicators of undesired
consequences. Moreover, unusualness in everyday life activities may also be
amusing to watch as proven by the popularity of such videos shared in social
media. Discovery of unusual events in videos is generally attacked as a problem
of finding usual patterns, and then separating the ones that do not resemble to
those. In this study, we address the problem from the other side, and try to
answer what type of patterns are shared among unusual videos that make them
resemble to each other regardless of the ongoing event. With this challenging
problem at hand, we propose a novel descriptor to encode the rapid motions in
videos utilizing densely extracted trajectories. The proposed descriptor, which
is referred to as trajectory snipped histograms, is used to distinguish unusual
videos from usual videos, and further exploited to discover snapshots in which
unusualness happen. Experiments on domain specific people falling videos and
unrestricted funny videos show the effectiveness of our method in capturing
unusualness.


title:
Kennard-Stepanov relation connecting absorption and emission spectra in
  an atomic gas

abstract:
  The Kennard-Stepanov relation describes a thermodynamic, Boltzmann-type
scaling between the absorption and emission spectral profiles of an absorber,
which applies in many liquid state dye solutions as well as in semiconductor
systems. Here we examine absorption and emission spectra of rubidium atoms in
dense argon buffer gas environment. We demonstrate that the Kennard-Stepanov
relation between absorption and emission spectra is well fulfilled in the
collisionally broadened atomic gas system. Our experimental findings are
supported by a simple theoretical model.


title: Hybridized/Coupled Multiple Resonances in Nacre

abstract:
  We report that nacre (also known as mother-of-pearl), a wondrous
nanocomposite found in nature, is a rich photonic nanomaterial allowing the
experimental realization of collective excitation and light amplification via
coupled states. Localized modes in three-dimensional complex media are
typically isolated in frequency and space. However, multiple local resonances
can be hybridized in multilayered nanostructures of nacre so that the effective
cavity size for efficient disordered resonators is scaled up. Localized modes
in hybridized states in nacre are overlapped in frequency with similar shapes
in space, thus being collectively excited and synergistically amplified. These
hybridized states boost light amplification, leading to stable and regular
multimode lasing at low excitation energy. The simplicity of ameliorating
disordered resonators by mimicking nacre can further serve as platforms for
developing cost-effective photonic systems and provide materials for
fundamental research on complex media


title: ConceptVision: A Flexible Scene Classification Framework

abstract:
  We introduce ConceptVision, a method that aims for high accuracy in
categorizing large number of scenes, while keeping the model relatively simpler
and efficient for scalability. The proposed method combines the advantages of
both low-level representations and high-level semantic categories, and
eliminates the distinctions between different levels through the definition of
concepts. The proposed framework encodes the perspectives brought through
different concepts by considering them in concept groups. Different
perspectives are ensembled for the final decision. Extensive experiments are
carried out on benchmark datasets to test the effects of different concepts,
and methods used to ensemble. Comparisons with state-of-the-art studies show
that we can achieve better results with incorporation of concepts in different
levels with different perspectives.