title: TLEP: A High-Performance Circular e+e- Collider to Study the Higgs Boson

abstract:
  The recent discovery of a light Higgs boson has opened up considerable
interest in circular e+e- Higgs factories around the world. We report on the
progress of the TLEP concept since last year. TLEP is an e+e- circular collider
capable of very high luminosities in a wide centre-of-mass (ECM) spectrum from
90 to 350 GeV. TLEP could be housed in a new 80 to 100 km tunnel in the Geneva
region. The design can be adapted to different ring circumference (e.g. LEP3 in
the 27 km LHC tunnel). TLEP is an ideal complementary machine to the LHC thanks
to high luminosity, exquisite determination of ECM and the possibility of four
interaction points, both for precision measurements of the Higgs boson
properties and for precision tests of the closure of the Standard Model from
the Z pole to the top threshold.


title: Quasar Cartography: from Black Hole to Broad Line Region Scales

abstract:
  A generalized approach to reverberation mapping (RM) is presented, which is
applicable to broad- and narrow-band photometric data, as well as to
spectroscopic observations. It is based on multivariate correlation analysis
techniques and, in its present implementation, is able to identify
reverberating signals across the accretion disk and the broad line region (BLR)
of active galactic nuclei (AGN). Statistical tests are defined to assess the
significance of time-delay measurements using this approach, and the
limitations of the adopted formalism are discussed. It is shown how additional
constraints on some of the parameters of the problem may be incorporated into
the analysis thereby leading to improved results. When applied to a sample of
14 Seyfert 1 galaxies having good-quality high-cadence photometric data,
accretion disk scales and BLR sizes are simultaneously determined, on a
case-by-case basis, in most objects. The BLR scales deduced here are in good
agreement with the findings of independent spectroscopic RM campaigns.
Implications for the photometric RM of AGN interiors in the era of large
surveys are discussed.


title: Graphene nano-ribbon waveguides

abstract:
  Graphene as a one-atom-thick platform for infrared metamaterial plays an
important role in optical science and engineering. Here we study the unique
properties of some plasmonic waveguides based on graphene nano-ribbon. It is
found that a graphene ribbon of finite width leads to the occurrence of coupled
edge mode. The single-mode region of a single freestanding graphene ribbon is
identified at a fixed frequency of 30 THz. A low-loss waveguide structure,
consisting of a graphene layer, a silica buffer layer and silicon substrate is
proposed to reduce the propagation loss and obtain a high figure of merit for
future integration of waveguide devices. Furthermore, two coupled ribbon
configurations, namely, side-side coupling and top-bottom coupling, are
investigated. As a device example, a nano-ring cavity of ultra-small size is
designed.


title: Metric Diophantine approximation on the middle-third Cantor set

abstract:
  Let $\mu\geq 2$ be a real number and let $\Mcal(\mu)$ denote the set of real
numbers approximable at order at least $\mu$ by rational numbers. More than
eighty years ago, Jarn\'i k and, independently, Besicovitch established that
the Hausdorff dimension of $\Mcal(\mu)$ is equal to $2/\mu$. We investigate the
size of the intersection of $\Mcal(\mu)$ with Ahlfors regular compact subsets
of the interval $[0, 1]$. In particular, we propose a conjecture for the exact
value of the dimension of $\Mcal(\mu)$ intersected with the middle-third Cantor
set and give several results supporting this conjecture. We especially show
that the conjecture holds for a natural probabilistic model that is intended to
mimic the distribution of the rationals. The core of our study relies heavily
on dimension estimates concerning the set of points lying in an Ahlfors regular
set and approximated at a given rate by a system of random points.


title: On the Eve property for CSBP

abstract:
  We consider the population model associated to continuous state branching
processes and we are interested in the so-called Eve property that asserts the
existence of an ancestor with an overwhelming progeny at large times, and more
generally, in the possible behaviours of the frequencies among the population
at large times. In this paper, we classify all the possible behaviours
according to the branching mechanism of the continuous state branching process.


title: Conjugation-free groups, lower central series and line arrangements

abstract:
  The quotients $G_k/G_{k+1}$ of the lower central series of a finitely
presented group $G$ are an important invariant of this group. In this work we
investigate the ranks of these quotients in the case of a certain class of
conjugation-free groups, which are groups generated by $x_1,...,x_n$, and
having only cyclic relations: $$ x_{i_t} x_{i_{t-1}} ... x_{i_1} = x_{i_{t-1}}
... x_{i_1} x_{i_t} = ... = x_{i_1} x_{i_t} ... x_{i_2}.$$ Using tools from
group theory and from the theory of line arrangements we explicitly find these
ranks, which depend only at the number and length of these cyclic relations. It
follows that for these groups the associated graded Lie algebra $gr(G)$
decomposes, in any degree, as a direct product of local components.


title: Photoionization Delay in He, Ne, Ar and Kr

abstract:
  We study photoionization of various noble gas atoms by attosecond pulses
produced in High Harmonic Generation (HHG). We use a pump-probe experiment to
measure the time delays of electrons photoionized from Neon, Argon, and Krypton
relative to those photoionized from Helium atoms. The Attosecond Pulse Train
(APT) is characterized and the relative delay in photoionization of various
noble gases is measured. The photoionization delay of Ne, Ar, and Kr is
determined using previously calculated values for the He atomic delay and the
delay associated with the probe process.


title: The Demon in a vacuum tube

abstract:
  In the present paper, several issues concerning the second law of
thermodynamics, Maxwell's demon and Landauer's principle are dealt with. I
argue that if the demon and the system on which it operates without dissipation
of external energy are made of atoms and molecules (gas, liquid or solid) in
thermal equilibrium (whose behaviour is described by a canonical distribution),
then the unavoidable reason why the demon cannot successfully operate resides
in the ubiquity of thermal fluctuations and friction. Landauer's principle
appears to be unnecessary. I also suggest that if the behaviour of the demon
and the system on which it acts is not always describable by a canonical
distribution, as would happen for instance with the ballistic motion of
electrons at early stages of thermionic emission, then a successful working
demon cannot be ruled out a priori. A critical review of two recent experiments
on thermionic emission Maxwell's demons is also given.


title: Notes on Physical & Logical Data Layouts

abstract:
  In this short note I review and discuss fundamental options for physical and
logical data layouts as well as the impact of the choices on data processing. I
should say in advance that these notes offer no new insights, that is,
everything stated here has already been published elsewhere. In fact, it has
been published in so many different places, such as blog posts, in the
literature, etc. that the main contribution is to bring it all together in one
place.


title:
The Case for Standard Irradiated Accretion Disks in Active Galactic
  Nuclei

abstract:
  We analyze the broadband photometric light curves of Seyfert 1 galaxies from
the Sergeev et al. (2005) sample and find that a) perturbations propagating
across the continuum emitting region are a general phenomenon securely detected
in most cases, b) it is possible to obtain reliable time-delays between
continuum emission in different wavebands, which are not biased by the
contribution of broad emission lines to the signal, and that c) such lags are
consistent with the predictions of standard irradiated accretion disk models,
given the optical luminosity of the sources. These findings provide new and
independent support for standard accretion disks being responsible for the bulk
of the (rest) optical emission in low-luminosity active galactic nuclei (AGN).
We interpret our lag measurements in individual objects within the framework of
this model and estimate the typical mass accretion rate to be <~0.1Msol/yr,
with little dependence on the black hole mass. Assuming bolometric corrections
typical of type-I sources, we find tentative evidence for the radiative
efficiency of accretion flows being a rising function of the black hole mass.
With upcoming surveys that will regularly monitor the sky, we may be able to
better quantify possible departures from standard self-similar models, and
identify other modes of accretion in AGN.


title:
Discovery of TeV Gamma-ray Emission Toward Supernova Remnant SNR
  G78.2+2.1

abstract:
  We report the discovery of an unidentified, extended source of
very-high-energy (VHE) gamma-ray emission, VER J2019+407, within the radio
shell of the supernova remnant SNR G78.2+2.1, using 21.4 hours of data taken by
the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary
indications of gamma-ray emission previously seen in a two-year (2007-2009)
blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected
at a post-trials significance of 7.5 standard deviations in the 2009 data, is
localized to the northwestern rim of the remnant in a region of enhanced radio
and X-ray emission. It has an intrinsic extent of 0.23^{\circ} \pm 0.03^{\circ}
(stat)+0.04^{\circ}_{-0.02}^{\circ}(sys) and its spectrum is well-characterized
by a differential power law (dN/dE = N_0 \times (E/TeV)^{-\Gamma}) with a
photon index of {\Gamma} = 2.37 \pm 0.14 (stat) \pm 0.20 (sys) and a flux
normalization of N0 = 1.5 \pm 0.2 (stat) \pm 0.4(sys) \times 10^-12 ph TeV^{-1}
cm^{-2} s^{-1}. This yields an integral flux of 5.2 \pm 0.8 (stat) \pm 1.4
(sys) \times 10^-12 ph cm^{-2} s^{-1} above 320 GeV, corresponding to 3.7% of
the Crab Nebula flux. We consider the relationship of the TeV gamma-ray
emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as
that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple
scenarios are considered as possible origins for the TeV gamma-ray emission,
including hadronic particle acceleration at the supernova remnant shock.


title: DR 21(OH): a highly fragmented, magnetized, turbulent dense core

abstract:
  We present high-angular-resolution observations of the massive star forming
core DR21(OH) at 880 mum using the Submillimeter Array (SMA). The dense core
exhibits an overall velocity gradient in a Keplerian-like pattern, which breaks
at the center of the core where SMA 6 and SMA 7 are located. The dust
polarization shows a complex magnetic field, compatible with a toroidal
configuration. This is in contrast with the large, parsec-scale filament that
surrounds the core, where there is a smooth magnetic field. The total magnetic
field strengths in the filament and in the core are 0.9 and 2.1 mG,
respectively. We found evidence of magnetic field diffusion at the core scales,
far beyond the expected value for ambipolar diffusion. It is possible that the
diffusion arises from fast magnetic reconnection in the presence of turbulence.
The dynamics of the DR 21(OH) core appear to be controlled energetically in
equal parts by the magnetic field, magneto-hydrodynamic (MHD) turbulence and
the angular momentum. The effect of the angular momentum (this is a fast
rotating core) is probably causing the observed toroidal field configuration.
Yet, gravitation overwhelms all the forces, making this a clear supercritical
core with a mass-to-flux ratio of ~6 times the critical value. However,
simulations show that this is not enough for the high level of fragmentation
observed at 1000 AU scales. Thus, rotation and outflow feedback is probably the
main cause of the observed fragmentation.


title:
An atom trap trace analysis system for measuring krypton contamination
  in xenon dark matter detectors

abstract:
  We have developed an atom trap trace analysis (ATTA) system to measure Kr in
Xe at the part per trillion (ppt) level, a prerequisite for the sensitivity
achievable with liquid xenon dark matter detectors beyond the current
generation. Since Ar and Kr have similar laser cooling wavelengths, the
apparatus has been tested with Ar to avoid contamination prior to measuring Xe
samples. A radio-frequency (RF) plasma discharge generates a beam of metastable
atoms which is optically collimated, slowed, and trapped using standard
magneto-optical techniques. Based on the measured overall system efficiency of
$1.2 \times 10^{-8}$ (detection mode) we expect the ATTA system to reach the
design goal sensitivity to ppt concentrations of Kr in Xe in $<2$ hours.


title:
Observation of $B^0_s\rightarrow\chi_{c1}\phi$ decay and study of
  $B^0\rightarrow\chi_{c1,2}K^{*0}$ decays

abstract:
  The first observation of the decay $B^0_s\rightarrow\chi_{c1}\phi$ and a
study of $B^0\rightarrow\chi_{c1,2}K^{*0}$ decays are presented. The analysis
is performed using a dataset, corresponding to an integrated luminosity of 1.0
fb$^{-1}$, collected by the LHCb experiment in pp collisions at a
centre-of-mass energy of 7 TeV. The following ratios of branching fractions are
measured: \begin{equation*} \begin{array}{lll}
\dfrac{\cal{B}(B^0_s\rightarrow\chi_{c1}\phi)}{\cal{B}(B^0_s\rightarrow
J/\psi\phi)} &=& (18.9 \pm1.8\,(stat)\pm1.3\,(syst)\pm0.8\,(\cal{B})) \times
10^{-2}, \nonumber \\ \noalign{\vskip 3pt}
\dfrac{\cal{B}(B^0\rightarrow\chi_{c1}K^{*0})}{\cal{B}(B^0\rightarrow
J/\psiK^{*0})} &=& (19.8 \pm1.1\,(stat)\pm1.2\,(syst)\pm0.9\,(\cal{B})) \times
10^{-2}, \nonumber \\ \noalign{\vskip 3pt}
\dfrac{\cal{B}(B^0\rightarrow\chi_{c2}K^{*0})}{\cal{B}(B^0\rightarrow\chi_{c
1}K^{*0})} &=& (17.1 \pm5.0\,(stat)\pm1.7\,(syst)\pm1.1\,(\cal{B})) \times
10^{-2}, \nonumber \\ \noalign{\vskip 3pt} \end{array} \end{equation*}
\noindent where the third uncertainty is due to the limited knowledge of the
branching fractions of ${\chi_{c}\rightarrow J/\psi \gamma}$ modes.


title: Quasiparticle GW calculations for solids, molecules and 2D materials

abstract:
  We present a plane wave implementation of the G0W0 approximation within the
projector augmented wave method code GPAW. The computed band gaps of ten bulk
semiconductors and insulators deviate on average by 0.2 eV (~ 5 %) from the
experimental values - the only exception being ZnO where the calculated band
gap is around 1 eV too low. Similar relative deviations are found for the
ionization potentials of a test set of 32 small molecules. The importance of
substrate screening for a correct description of quasiparticle energies and
Fermi velocities in supported 2D materials is illustrated by the case of
graphene/h-BN interfaces. Due to the long range Coulomb interaction between
periodically repeated images, the use of a truncated interaction is found to be
essential for obtaining converged results for 2D materials. For all systems
studied, a plasmon pole approximation is found to reproduce the full frequency
results to within 0.2 eV with a significant gain in computational speed. As
alternative to G0W0, the efficient local GLLBSC potential yields significantly
better results than the PBE0 hybrid. For completeness, we provide a
mathematically rigorous and physically transparent introduction to the notion
of quasiparticle states.


title: Analytical Treatment of Planetary Resonances

abstract:
  An ever-growing observational aggregate of extrasolar planets has revealed
that systems of planets that reside in or near mean-motion resonances are
relatively common. While the origin of such systems is attributed to
protoplanetary disk-driven migration, a qualitative description of the
dynamical evolution of resonant planets remains largely elusive. Aided by the
pioneering works of the last century, we formulate an approximate, integrable
theory for first-order resonant motion. We utilize the developed theory to
construct an intuitive, geometrical representation of resonances within the
context of the unrestricted three-body problem. Moreover, we derive a simple
analytical criterion for the appearance of secondary resonances between
resonant and secular motion. Subsequently, we demonstrate the onset of rapid
chaotic motion as a result of overlap among neighboring first-order mean-motion
resonances, as well as the appearance of slow chaos as a result of secular
modulation of the planetary orbits. Finally, we take advantage of the
integrable theory to analytically show that, in the adiabatic regime, divergent
encounters with first-order mean-motion resonances always lead to persistent
apsidal anti-alignment.


title:
Nonlinear-dissipation-induced Entanglement of Coupled Nonlinear
  Oscillators

abstract:
  The quantum dynamics of two weakly coupled nonlinear oscillators is
analytically and numerically investigated in the context of nonlinear
dissipation. The latter facilitates the creation and preservation of
non-classical steady states. Starting from a microscopic description of two
oscillators individually interacting with their dissipative environments, it is
found that in addition to energy relaxation, dephasing arises due to the mutual
coupling. Using the negativity as an entanglement measure, it is shown that the
coupling entangles the oscillators in the long-time limit. For finite
temperatures, entanglement sudden death and rebirth are observed.


title:
Effect of the toroidal magnetic field on the runaway instability of
  relativistic tori

abstract:
  Runaway instability operates in fluid tori around black holes. It affects
systems close to the critical (cusp overflowing) configuration. The runaway
effect depends on the radial profile l(R) of the angular momentum distribution
of the fluid, on the dimension-less spin a of the central black hole, and other
factors, such as self-gravity. Previously it was demonstrated that, for the
power-law dependence of the radial angular momentum profile, non-magnetized
tori always become runaway stable for a sufficiently high positive value of q.
Here we discuss the role of runaway instability within a framework of an
axially symmetric model of perfect fluid endowed with a purely toroidal
magnetic field. The gradual accretion of material over the cusp transfers the
mass and angular momentum into the black hole, thereby changing the intrinsic
parameters of the Kerr metric. We studied the effect of the ratio of gas to
magnetic pressure and other parameters of the model on the evolution of
critical configurations that are just on the verge of cusp overflow. We show
that the toroidal magnetic component inside an accretion torus does not change
the frequency of its oscillations significantly. We identify these oscillations
as the radial epicyclic mode. These weak effects can trigger the runaway
instability even in situations when the purely hydrodynamical regime of the
torus is stable. On the other hand, in most cases the stable configuration
remains unaffected, and the initial deviations gradually decay after several
orbital periods. We show examples of the torus evolution depending on the
initial magnetization beta, the slope q, and the spin a. The toroidal magnetic
field plays a more important role in the early phases of the accretion process
until the perturbed configuration finds a new equilibrium or disappears because
of the runaway instability.


title:
Delaunay type domains for an overdetermined elliptic problem in S^n x R
  and H^n x R

abstract:
  We prove the existence of a countable family of Delaunay type domains
\Omega_j in M^n x R, where M^n is the Riemannian manifold S^n or H^n and n is
at least 2, bifurcating from the cylinder B^n x R (where B^n is a geodesic ball
of radius 1 in M^n) for which the first eigenfunction of the Laplace-Beltrami
operator with zero Dirichlet boundary condition also has constant Neumann data
at the boundary. The domains \Omega_j are rotationally symmetric and periodic
with respect to the R-axis of the cylinder and as j converges to 0 the domain
\Omega_j converges to the cylinder B^n x R.


title:
Covariant formulation for the optimal control of jointed arm robots: an
  alternative to Pontryagin's principle

abstract:
  We elaborate algorithms able to efficiently command the actuators of an
articulated robot. Our time discretization method is based on cubic and quintic
Hermite Finite Elements. The suggested control optimization consists in
minimizing directly the selected criterium by a conjugate gradient type
algorithm. A generic example illustrates the super convergence of the Hermite's
technique.


title:
Spin fluctuations with two-dimensional XY behavior in a frustrated S =
  1/2 square-lattice ferromagnet

abstract:
  The spin dynamics of the layered square-lattice vanadate Pb2VO(PO4)2 is
investigated by electron spin resonance at various magnetic fields and at
temperatures above magnetic ordering. The linewidth divergence towards low
temperatures seems to agree with isotropic Heisenberg-type spin exchange
suggesting that the spin relaxation in this quasi-two dimensional compound is
governed by low-dimensional quantum fluctuations. However, a weak easy- plane
anisotropy of the g factor points to the presence of a planar XY type of
exchange. Indeed, we found that the linewidth divergence is described best by
XY-like spin fluctuations which requires a single parameter only. Therefore,
ESR-probed spin dynamics could establish Pb2VO(PO4)2 as the first frustrated
square lattice system with XY-inherent spin topological fluctuations.


title:
Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum
  and composition

abstract:
  We discuss the effects of diffusion of high energy cosmic rays in turbulent
extra-galactic magnetic fields. We find an approximate expression for the low
energy suppression of the spectrum of the different mass components (with
charge $Z$) in the case in which this suppression happens at energies below
$\sim Z$ EeV, so that energy losses are dominated by the adiabatic ones.
  The low energy suppression appears when cosmic rays from the closest sources
take a time comparable to the age of the Universe to reach the Earth. This
occurs for energies $E< Z\, {\rm EeV}\,(B/{{\rm G}})\sqrt{l_c/{\rm
Mpc}}(d_s/70\ {\rm Mpc})$ in terms of the magnetic field RMS strength $B$, its
coherence length $l_c$ and the typical separation between sources $d_s$.
  We apply this to scenarios in which the sources produce a mixed composition
and have a relatively low maximum rigidity ($E_{max}\sim (2$--$10) Z $ EeV),
finding that diffusion has a significant effect on the resulting spectrum, the
average mass and on its spread, in particular reducing this last one. For
reasonable values of $B$ and $l_c$ these effects can help to reproduce the
composition trends observed by the Auger Collaboration for source spectra
compatible with Fermi acceleration.


title:
Design of Wideband Microstrip Filters with Non-Equiripple Responses and
  Low Sensitivity

abstract:
  This paper presents a novel design procedure for wideband microstrip bandpass
filters with non-equiripple filtering frequency responses and low sensitivity.
Different from the traditional Chebyshev transfer function filters, the return
loss zeros of the proposed non-equiripple filters can be redistributed within
the operating passband. For the industrial applications, the proposed filters
have a reduced sensitivity to manufacturing errors and exhibit good tolerance
control for both specified bandwidth and maximum in-band reflection loss. By
deriving the transfer functions, a synthesis approach with a set of non-linear
equations can be established according to the specifications such as the
bandwidth and predetermined reflection lobes. Without performing any post
optimization in the full-wave simulation, the non-equiripple synthesized
results have less sensitivity and fractional bandwidth (delta) error in
comparison with those obtained from traditional Chebyshev transfer functions
with equiripple frequency responses. As design examples, a four-pole bandpass
filter with delta=60% and a five-pole bandpass filter with delta=82.5% are
designed and fabricated. Measured results show a good agreement with those
obtained from the prediction, without any tuning or adjustments.


title: Self-interacting Dark Radiation

abstract:
  We consider a simple class of models where dark radiation has
self-interactions and therefore does not free stream. Such dark radiation has
no anisotropic stress (or viscosity), leaving a distinct signature on the CMB
angular power spectrum. Specifically we study a possibility that hidden gauge
bosons and/or chiral fermions account for the excess of the effective number of
neutrino species. They have gauge interactions and remain light due to the
unbroken hidden gauge symmetry, leading to \Delta N_{\rm eff} \simeq 0.29 in
some case.


title:
Probability Distribution Function for the Euclidean Distance Between Two
  Telegraph Processes

abstract:
  Consider two independent Goldstein-Kac telegraph processes $X_1(t)$ and
$X_2(t)$ on the real line $\Bbb R$. The processes $X_k(t), \; k=1,2,$ are
performed by stochastic motions at finite constant velocities $c_1>0, \;
c_2>0,$ that start at the initial time instant $t=0$ from the origin of the
real line $\Bbb R$ and are controlled by two independent homogeneous Poisson
processes of rates $\lambda_1>0, \; \lambda_2>0$, respectively. Closed-form
expression for the probability distribution function of the Euclidean distance
$$\rho(t) = |X_1(t) - X_2(t) |, \qquad t>0,$$ between these processes at
arbitrary time instant $t>0$, is obtained. Some numerical results are
presented.


title:
Optimal Convergence Rates and One-Term Edgeworth Expansions for
  Multidimensional Functionals of Gaussian Fields

abstract:
  We develop techniques for determining the exact asymptotic speed of
convergence in the multidimensional normal approximation of smooth functions of
Gaussian fields. As a by-product, our findings yield exact limits and often
give rise to one-term generalized Edgeworth expansions increasing the speed of
convergence. Our main mathematical tools are Malliavin calculus, Stein's method
and the Fourth Moment Theorem. This work can be seen as an extension of the
results of arXiv:0803.0458 to the multi-dimensional case, with the notable
difference that in our framework covariances are allowed to fluctuate. We apply
our findings to exploding functionals of Brownian sheets, vectors of Toeplitz
quadratic functionals and the Breuer-Major Theorem.


title:
Study of Scheme Transformations to Remove Higher-Loop Terms in the
  $\beta$ Function of a Gauge Theory

abstract:
  Since three-loop and higher-loop terms in the $\beta$ function of a gauge
theory are scheme-dependent, one can, at least for sufficiently small coupling,
carry out a scheme transformation that removes these terms. A basic question
concerns the extent to which this can be done at an infrared fixed point of an
asymptotically free gauge theory. This is important for quantitative analyses
of the scheme dependence of such a fixed point. Here we study a scheme
transformation $S_{R,m}$ with $m \ge 2$ that is constructed so as to remove the
terms in the beta function at loop order $\ell=3$ to $\ell=m+1$, inclusive.
Starting from an arbitrary initial scheme, we present general expressions for
the coefficients of terms of loop order $\ell$ in the beta function in the
transformed scheme from $\ell=m+2$ up to $\ell=8$. Extending a previous study
of $S_{R,2}$, we investigate the range of applicability of the $S_{R,3}$ scheme
transformation in an asymptotically free SU($N_c$) gauge theory with an
infrared zero in $\beta$ depending on the number, $N_f$, of fermions in the
theory. We show that this $S_{R,3}$ scheme transformation can only be applied
self-consistently in a restricted range of $N_f$ with a correspondingly small
value of infrared fixed-point coupling. We also study the effect of higher-loop
terms on the beta function of a U(1) gauge theory.


title: Ramanujan's cubic transformation and generalized modular equation

abstract:
  We study the quotient of hypergeometric functions \begin{equation*}
\mu_{a}^*(r)=\frac{\pi}{2\sin{(\pi a)}}\frac{F(a,1-a;1;1-r^3)}{F(a,1-a;1;r^3)}
\quad (r\in(0,1)) \end{equation*} in the theory of Ramanujan's generalized
modular equation for $a\in(0,1/2]$, find an infinite product formula for
$\mu_{1/3}^*(r)$ by use of the properties of $\mu_{a}^*(r)$ and Ramanujan's
cubic transformation. Besides, a new cubic transformation formula of
hypergeometric function is given, which complements the Ramanujan's cubic
transformation.


title:
Adaptive estimation of the copula correlation matrix for semiparametric
  elliptical copulas

abstract:
  We study the adaptive estimation of copula correlation matrix $\Sigma$ for
the semi-parametric elliptical copula model. In this context, the correlations
are connected to Kendall's tau through a sine function transformation. Hence, a
natural estimate for $\Sigma$ is the plug-in estimator $\hat{\Sigma}$ with
Kendall's tau statistic. We first obtain a sharp bound on the operator norm of
$\hat{\Sigma}-\Sigma$. Then we study a factor model of $\Sigma$, for which we
propose a refined estimator $\widetilde{\Sigma}$ by fitting a low-rank matrix
plus a diagonal matrix to $\hat{\Sigma}$ using least squares with a nuclear
norm penalty on the low-rank matrix. The bound on the operator norm of
$\hat{\Sigma}-\Sigma$ serves to scale the penalty term, and we obtain finite
sample oracle inequalities for $\widetilde{\Sigma}$. We also consider an
elementary factor copula model of $\Sigma$, for which we propose closed-form
estimators. All of our estimation procedures are entirely data-driven.


title: Wigner transport equation with finite coherence length

abstract:
  The use of the Wigner function for the study of quantum transport in open
systems present severe criticisms. Some of the problems arise from the
assumption of infinite coherence length of the electron dynamics outside the
system of interest. In the present work the theory of the Wigner function is
revised assuming a finite coherence length. A new dynamical equation is found,
corresponding to move the Wigner momentum off the real axis, and a numerical
analysis is performed for the case of study of the onedimensional potential
barrier.


title: Brauer algebras of type H3 and H4

abstract:
  In this paper, we will present Brauer algebras associated to spherical
Coxeter groups of type H3 and H4, which are also can be regarded as subalgebras
of Brauer algebras D6 and E8 by Muhlherr's admissible partition. Also some
basic properties will be described here.


title: Sum formula for finite multiple zeta values

abstract:
  The sum formula is one of the most well-known relations among multiple zeta
values. This paper proves a conjecture of Kaneko predicting that an analogous
formula holds for finite multiple zeta values.


title: Minimal idempotent ultrafilters and the Auslander-Ellis theorem

abstract:
  We characterize the existence of minimal idempotent ultrafilters (on N) in
the style of reverse mathematics and higher-order reverse mathematics using the
Auslander-Ellis theorem and variant thereof.
  We obtain that the existence of minimal idempotent ultrafilters restricted to
countable algebras of sets is equivalent to the Auslander-Ellis theorem (AET)
and that the existence of minimal idempotent ultrafilters as higher-order
objects is $\Pi^1_2$-conservative over a refinement of AET.


title: WZ and W+jets production at large transverse momenta beyond NLO

abstract:
  We present a study of higher order QCD corrections beyond NLO to processes
with electroweak vector bosons. We focus on the regions of high transverse
momenta of commonly used differential distributions. We employ the LoopSim
method, combined with NLO packages, VBFNLO and MCFM, to merge the NLO samples
with different multiplicities, in order to compute the dominant part of the
NNLO corrections at high pT. We find that these corrections are indeed
substantial, in the 30%-100% range, for a number of experimentally relevant
observables. For other observables, they lead to significant reduction of scale
uncertainties.


title:
The nonlinear Dirac equation in Bose-Einstein condensates: I.
  Relativistic solitons in armchair nanoribbon optical lattices

abstract:
  We present a thorough analysis of soliton solutions to the
quasi-one-dimensional nonlinear Dirac equation (NLDE) for a Bose-Einstein
condensate in a honeycomb lattice with armchair geometry. Our NLDE corresponds
to a quasi-one-dimensional reduction of the honeycomb lattice along the zigzag
direction, in direct analogy to graphene nanoribbons. Excitations in the
remaining large direction of the lattice correspond to the linear subbands in
the armchair nanoribbon spectrum. Analytical as well as numerical soliton Dirac
spinor solutions are obtained. We analyze the solution space of the
quasi-one-dimensional NLDE by finding fixed points, delineating the various
regions in solution space, and through an invariance relation which we obtain
as a first integral of the NLDE. We obtain spatially oscillating multi-soliton
solutions as well as asymptotically flat single soliton solutions using five
different methods: by direct integration; an invariance relation; parametric
transformation; a series expansion; and by numerical shooting. By tuning the
ratio of the chemical potential to the nonlinearity for a fixed value of the
energy-momentum tensor, we can obtain both bright and dark solitons over a
nonzero density background.


title: Sequences of preimages in elementary cellular automata

abstract:
  We search for regularities in the sequences of numbers of preimages for
elementary cellular automata. For 46 out of 88 "minimal" rules, we find
recognizable patterns, usually in the form of second order recurrence equations
with constant coefficients. Introducing the concept of asymptotic emulation of
CA rules, we then show how the regularities in the sequences of preimage
numbers can be used to find rules emulating identity. We also show that the
average density of nonzero sites after arbitrary number of steps (starting from
disordered configuration) can be computed using the sequences of preimage
numbers.


title:
Disk complexes and genus two Heegaard splittings for non-prime
  3-manifolds

abstract:
  Given a genus two Heegaard splitting for a non-prime 3-manifold, we define a
special subcomplex of the disk complex for one of the handlebodies of the
splitting, and then show that it is contractible. As applications, first we
show that the complex of Haken spheres for the splitting is contractible, which
refines the results of Lei and Lei-Zhang. Secondly, we classify all the genus
two Heegaard splittings for non-prime 3-manifolds, which is a generalization of
the result of Montesinos-Safont. Finally, we show that the mapping class group
of the splitting, called the Goeritz group, is finitely presented by giving its
explicit presentation.


title:
Study of $\chi_{c0}(1P) --> J/\psi \gamma $ and $\chi_{b0}(1P) -->
  \Upsilon(1S) \gamma $ decays via QCD sum rules

abstract:
  In this study we present the first theoretical calculation of the form factor
of the $\chi_{c0}(1P) \rar J/\psi \gamma $ and $\chi_{b0}(1P) \rightarrow
\Upsilon(1S) \gamma $ decays in the frame work of QCD sum rules. We also find
branching ratio ${\cal B}_r(\chi_{c0}(1P) \rightarrow J/\psi
\gamma)=(1.07\times \pm 0.14) \times 10^{(-2)} $ which is in agreement with the
experimental data. Furthermore, we estimate the $\Gamma_{tot}(\chi_{b0}(1P))
=5.5\pm 0.5 $ MeV, where experimental bound for full width of $\chi_{b0}$ is
$\Gamma_{tot}(\chi_{b0}(1P)) <6 $ MeV.


title: Entanglement Spectroscopy using Quantum Monte Carlo

abstract:
  We present a numerical scheme to reconstruct a subset of the entanglement
spectrum of quantum many body systems using quantum Monte Carlo. The approach
builds on the replica trick to evaluate particle number resolved traces of the
first n of powers of a reduced density matrix. From this information we
reconstruct n entanglement spectrum levels using a polynomial root solver. We
illustrate the power and limitations of the method by an application to the
extended Bose-Hubbard model in one dimension where we are able to resolve the
quasi-degeneracy of the entanglement spectrum in the Haldane-Insulator phase.
In general the method is able to reconstruct the largest few eigenvalues in
each symmetry sector and typically performs better when the eigenvalues are not
too different.


title:
A Cooperative Coevolutionary Genetic Algorithm for Learning Bayesian
  Network Structures

abstract:
  We propose a cooperative coevolutionary genetic algorithm for learning
Bayesian network structures from fully observable data sets. Since this problem
can be decomposed into two dependent subproblems, that is to find an ordering
of the nodes and an optimal connectivity matrix, our algorithm uses two
subpopulations, each one representing a subtask. We describe the empirical
results obtained with simulations of the Alarm and Insurance networks. We show
that our algorithm outperforms the deterministic algorithm K2.


title:
Quantum Entanglement and Thermal Reduced Density Matrices in Fermion and
  Spin Systems on Ladders

abstract:
  Numerical studies of the reduced density matrix of a gapped spin-1/2
Heisenberg antiferromagnet on a two-leg ladder find that it has the same form
as the Gibbs density matrix of a gapless spin-1/2 Heisenberg antiferromagnetic
chain at a finite temperature determined by the spin gap of the ladder. We
investigate this interesting result by considering a model of free fermions on
a two-leg ladder (gapped by the inter-chain tunneling operator) and in spin
systems on a ladder with a gapped ground state using exact solutions and
several controlled approximations. We calculate the reduced density matrix and
the entanglement entropy for a leg of the ladder (i.e. cut made between the
chains). In the fermionic system we find the exact form of the reduced density
matrix for one of the chains and determine the entanglement spectrum
explicitly. Here we find that in the weak tunneling limit of the ladder the
entanglement entropy of one chain of the gapped ladder has a simple and
universal form dictated by conformal invariance. In the case of the spin
system, we consider the strong coupling limit by using perturbation theory and
get the reduced density matrix by the Schmidt decomposition. The entanglement
entropies of a general gapped system of two coupled conformal field theories
(in 1+1 dimensions) is discussed using the replica trick and scaling arguments.
We show that 1) for a system with a bulk gap the reduced density matrix has the
form of a thermal density matrix, 2) the long-wavelength modes of one subsystem
(a chain) of a gapped coupled system are always thermal, 3) the von Neumann
entropy equals to the thermodynamic entropy of one chain, and 4) the bulk gap
plays the role of effective temperature.

categories: cond-mat.str-el cond-mat.stat-mech hep-th quant-ph


title:
Universal deformation rings of group representations, with an
  application of Brauer's generalized decomposition numbers

abstract:
  We give an introduction to the deformation theory of linear representations
of profinite groups which Mazur initiated in the 1980's. We then consider the
case of representations of finite groups. We show how Brauer's generalized
decomposition numbers can be used in some cases to explicitly determine
universal deformation rings.


title: Hexagonal patterns in a simplified model for block copolymers

abstract:
  In this paper we study a new model for patterns in two dimensions, inspired
by diblock copolymer melts with a dominant phase. The model is simple enough to
be amenable not only to numerics but also to analysis, yet sophisticated enough
to reproduce hexagonally packed structures that resemble the cylinder patterns
observed in block copolymer experiments.
  Starting from a sharp-interface continuum model, a nonlocal energy functional
involving a Wasserstein cost, we derive the new model using Gamma-convergence
in a limit where the volume fraction of one phase tends to zero. The limit
energy is defined on atomic measures; in three dimensions the atoms represent
small spherical blobs of the minority phase, in two dimensions they represent
thin cylinders of the minority phase.
  We then study minimisers of the limit energy. Numerical minimisation is
performed in two dimensions by recasting the problem as a computational
geometry problem involving power diagrams. The numerical results suggest that
the small particles of the minority phase tend to arrange themselves on a
triangular lattice as the number of particles goes to infinity. This is proved
in the companion paper Bourne, Peletier & Theil and agrees with patterns
observed in block copolymer experiments. This is a rare example of a nonlocal
energy-driven pattern formation problem in two dimensions where it can be
proved that the optimal pattern is periodic.


title:
BSDEs with singular terminal condition and control problems with
  constraints

abstract:
  We provide a probabilistic solution of a not necessarily Markovian control
problem with a state constraint by means of a Backward Stochastic Differential
Equation (BSDE). The novelty of our solution approach is that the BSDE
possesses a singular terminal condition. We prove that a solution of the BSDE
exists, thus partly generalizing existence results obtained by Popier in [7]
and [8]. We perform a verification and discuss special cases for which the
control problem has explicit solutions.


title: Surfaces in 4-manifolds: Concordance, Isotopy, and Surgery

abstract:
  In this paper we will show that two surfaces of the same genus and homology
class in a simply connected 4-manifold are concordant. We will show they are
often topologically isotopic when their complements have cyclic fundamental
group. Finally, we will show that if they are 0-concordant, then surgery on one
is equivalent to surgery on the other.


title: MirrorShard: Proof by Computational Reflection with Verified Hints

abstract:
  We describe a method for building composable and extensible verification
procedures within the Coq proof assistant. Unlike traditional methods that rely
on run-time generation and checking of proofs, we use verified-correct
procedures with Coq soundness proofs. Though they are internalized in Coq's
logic, our provers support sound extension by users with hints over new
domains, enabling automated reasoning about user-defined abstract predicates.
We maintain soundness by developing an architecture for modular packaging,
construction, and composition of hint databases, which had previously only been
implemented in Coq at the level of its dynamically typed, proof-generating
tactic language. Our provers also include rich handling of unification
variables, enabling integration with other tactic-based deduction steps within
Coq. We have implemented our techniques in MirrorShard, an open-source
framework for reflective verification. We demonstrate its applicability by
instantiating it to separation logic in order to reason about imperative
program verification.


title:
Influence of hadronic bound states above $T_c$ on heavy-quark
  observables in Pb+Pb collisions at at the CERN Large Hadron Collider

abstract:
  We investigate how the possible existence of hadronic bound states above the
deconfinement transition temperature $T_c$ affects heavy-quark observables like
the nuclear modification factor, the elliptic flow and azimuthal correlations.
Lattice QCD calculations suggest that above $T_c$ the effective degrees of
freedom might not be exclusively partonic but that a certain fraction of
hadronic degrees of freedom might already form at higher temperatures. This is
an interesting questions by itself but also has a strong influence on other
probes of the strongly interacting matter produced in ultrarelativistic
heavy-ion collisions. A substantial fraction of hadronic bound states above
$T_c$ reduces on average the interaction of the heavy quarks with colored
constituents of the medium. We find that all studied observables are highly
sensitive to the active degrees of freedom in the quark-gluon plasma.


title:
Construction of all general symmetric informationally complete
  measurements

abstract:
  We construct the set of all general (i.e. not necessarily rank 1) symmetric
informationally complete (SIC) positive operator valued measures (POVMs). In
particular, we show that any orthonormal basis of a real vector space of
dimension d^2-1 corresponds to some general SIC POVM and vice versa. Our
constructed set of all general SIC-POVMs contains weak SIC-POVMs for which each
POVM element can be made arbitrarily close to a multiple times the identity. On
the other hand, it remains open if for all finite dimensions our constructed
family contains a rank 1 SIC-POVM.


title: Finite group actions on Kervaire manifolds

abstract:
  The (4k+2)-dimensional Kervaire manifold is a closed, piecewise linear (PL)
manifold with Kervaire invariant 1 and the same homology as the product of two
(2k+1)-dimensional spheres. We show that a finite group of odd order acts
freely on a Kervaire manifold if and only if it acts freely on the
corresponding product of spheres. If the Kervaire manifold M is smoothable,
then each smooth structure on M admits a free smooth involution. If k + 1 is
not a 2-power, then the Kervaire manifold in dimension 4k+2 does not admit any
free TOP involutions. Free "exotic" (PL) involutions are constructed on the
Kervaire manifolds of dimensions 30, 62, and 126. Each smooth structure on the
30-dimensional Kervaire manifold admits a free Z/2 x Z/2 action.


title: On the ergodic theorem for affine actions on Hilbert space

abstract:
  This note establishes a new weak mean ergodic theorem for 1-cocycles
associated to weakly mixing representations of amenable groups.


title:
Adaptive Optics Images II: 12 Kepler Objects of Interest and 15
  Confirmed Transiting Planets

abstract:
  All transiting planet observations are at risk of contamination from nearby,
unresolved stars. Blends dilute the transit signal, causing the planet to
appear smaller than it really is, or produce a false positive detection when
the target star is blended with an eclipsing binary. High spatial resolution
adaptive optics images are the best way of resolving undetected contaminants.
Here we present companions and detection limits for 12 Kepler candidates, of
which 4 have companions within 4 arcsec. One system (KOI 1537) consists of two
similar-magnitude stars separated by 0.1 arcsec, while KOI 174 has a companion
at 0.5 arcsec. In addition, observations were made of 15 transiting planets
that were previously discovered by other surveys. The only companion found
within 1 arcsec of a known planet is the previously identified companion to
WASP-2b. An additional four systems have companions between 1-4 arcsec:
HAT-P-30b (3.7 arcsec, Delta Ks = 2.9), HAT-P-32b (2.9 arcsec, Delta Ks = 3.4),
TrES-1b (2.3 arcsec, Delta Ks = 7.7), and WASP-P-33b (1.9 arcsec, Delta Ks =
5.5), some of which have not been reported previously. Depending on the spatial
resolution of the transit photometry for these systems, these companion stars
may require a reassessment of the planetary parameters derived from transit
light curves. For all systems observed, we report the limiting magnitudes of
additional objects located 0.1-4 arcsec from the target.


title: Application of the 3-space approach to the Bianchi II cosmological model

abstract:
  Einstein used 4-dimensional space time geometry to explain gravity. However,
in 1962, Baierlein, Sharp and Wheeler proposed a Jacobi type timeless
Lagrangian based on the 3-dimensional geometry of space to reproduce the same
physics. In 2002, Barbour $et$. $al$. further extended this idea and they call
it 3-space approach. Here we use Bianchi II cosmological model to demonstrate
the 3-space idea. Indeed, we find that this theory is more fundamental and the
manipulation is more practical. We recover the known and find a new solutions.


title:
Millimetric and sub-millimetric observations of IRAS 05327+3404 "Holoea"
  in M36

abstract:
  The transition between the proto-star, Class I, and the pre-main sequence
star, Class II, phases is still one of the most uncertain, and important,
stages in the knowledge of the process of formation of an individual star,
because it is the stage that determines the final mass of the star. We observed
the YSO "Holoea", associated with IRAS 05327+3404, which was classified as an
object in transition between the Class I and Class II phases with several
unusual properties, and appears to be surrounded by large amounts of
circumstellar material. We used the SMA and BIMA telescopes at millimeter and
sub-millimeter wavelengths to observe the dust continuum emission and the CO
(1-0) and (2-1), HCO+ (1-0) and (3-2), and HCN (1-0) transitions in the region
around IRAS 05327+3404. We detected two continuum emission peaks at 1.1-mm: SMM
1, the sub-mm counterpart of IRAS 05327+3404, and SMM 2, ~6 arcsec to the West.
The emissions of the three molecules show marked differences. The CO emission
near the systemic velocity is filtered out by the telescopes, and CO mostly
traces the high-velocity gas. The HCO+ and HCN emissions are more centrally
concentrated around the central parts of the region, and show several intensity
peaks coincident with the sub-mm continuum peaks. We identify two main
molecular outflows: a bipolar outflow in an E-W direction that would be powered
by SMM 1 and another one in a NE direction, which we associate with SMM 2. We
propose that the SMM sources are probably Class I objects, with SMM 1 in an
earlier evolutionary stage.


title:
Statistical mechanical expression of entropy production for an open
  quantum system

abstract:
  A quantum statistical expression for the entropy of a nonequilibrium system
is defined so as to be consistent with Gibbs' relation, and is shown to
corresponds to dynamical variable by introducing analogous to the Heisenberg
picture in quantum mechanics. The general relation between system-reservoir
interactions and an entropy change operator in an open quantum system, relying
just on the framework of statistical mechanics and the definition of von
Neumann entropy. By using this formula, we can obtain the correct entropy
production in the linear response framework. The present derivation of entropy
production is directly based on the first principle of microscopic
time-evolution, while the previous standard argument is due to the
thermodynamic energy balance.


title:
Rotationally symmetric p-harmonic flows from D^2 to S^2: local
  well-posedness and blow-up

abstract:
  We study the $p$-harmonic flow from the unit disk $D^2$ to the unit sphere
$S^2$ under rotational symmetry. We show that the Dirichlet problem with
constant boundary conditions is locally well-posed in the class of classical
solutions and we also give a sufficient criterion, in terms of the boundary
condition, for the derivative of the solutions to blow-up in finite time.


title: Wave Mechanics: Behavior of a Distributed Electron Charge in an Atom

abstract:
  In Part one of this Paper a hypothesis is forwarded of the electron charge in
an atom existing in a distributed form. To check it by methods of
electrodynamics and mechanics (without invoking the formalism of quantum
mechanics and the concepts of the wave function and of the operators), the
potential, kinetic, and total energies were calculated for three states of the
hydrogen atom, which were found to agree closely with the available
experimental data. The Part two of the Paper offers additional assumptions
concerning various scenarios of motion of elements of the distributed electron
charge which obey fully the laws of theoretical mechanics. The angular momentum
of the ground-state hydrogen atom calculated in the frame of theoretical
mechanics is shown to coincide with the spin which is $\hbar/2$.


title:
Use of B->J/\psi f0 decays to discern the q anti-q or tetraquark nature
  of scalar mesons

abstract:
  We consider the relative decay rates of B0 and Bs mesons into a J\psi\ plus a
light scalar meson either the f0(500) (\sigma) or the f0(980). We show that it
is possible to distinguish between the quark content of the scalars being
quark-antiquark or tetraquark by measuring specific ratios of decay rates.
Using current data we determine the ratio of form-factors in Bs->J\psi f0(980)
with respect to B0->J\psi f0(500) decays to be 1.02(+0.14, -0.04) at a
four-momentum transfer squared equal to the mass of the J\psi\ meson squared.
In the case where these light mesons are considered to be quark-antiquark
states, we give a determination of the mixing angle between strange and light
quark states of less than 28 degrees at 90% confidence level. We also discuss
the use of a similar ratio to investigate the structure of other isospin
singlet states.


title: Reallocation Problems in Scheduling

abstract:
  In traditional on-line problems, such as scheduling, requests arrive over
time, demanding available resources. As each request arrives, some resources
may have to be irrevocably committed to servicing that request. In many
situations, however, it may be possible or even necessary to reallocate
previously allocated resources in order to satisfy a new request. This
reallocation has a cost. This paper shows how to service the requests while
minimizing the reallocation cost. We focus on the classic problem of scheduling
jobs on a multiprocessor system. Each unit-size job has a time window in which
it can be executed. Jobs are dynamically added and removed from the system. We
provide an algorithm that maintains a valid schedule, as long as a sufficiently
feasible schedule exists. The algorithm reschedules only a total number of
O(min{log^* n, log^* Delta}) jobs for each job that is inserted or deleted from
the system, where n is the number of active jobs and Delta is the size of the
largest window.


title: Schrodinger Sigma Models and Jordanian Twists

abstract:
  We proceed to study the integrable structures of two-dimensional non-linear
sigma models defined on three-dimensional Schrodinger spacetimes. We show that
anisotropic Lax pairs are equivalent with isotropic Lax pairs with flat
conserved currents under non-local gauge transformations. Then a quite
non-trivial realization of the undeformed Yangian symmetry Y(sl(2)) is revealed
after an appropriate gauge fixing, which is determined by comparing the gauge
transformation to a quantum Jordanian twist. As a result, an exotic symmetry
found in arXiv:1209.4147 may be interpreted as a Jordanian deformation of
Y(sl(2)).


title:
Geometric results on linear actions of reductive Lie groups for
  applications to homogeneous dynamics

abstract:
  Several problems in number theory when reformulated in terms of homogenous
dynamics involve study of limiting distributions of translates of algebraically
defined measures on orbits of reductive groups. The general non-divergence and
linearization techniques, in view of Ratner's measure classification for
unipotent flows, reduce such problems to dynamical questions about linear
actions of reductive groups on finite dimensional vectors spaces. This article
provides general results which resolve these linear dynamical questions in
terms of natural group theoretic or geometric conditions.


title: Dilepton creation based on an analytic hydrodynamic solution

abstract:
  High-energy collisions of various nuclei, so called ``Little Bangs'' are
observed at various experiments of heavy ion colliders. The time evolution of
the strongly interacting quark-gluon plasma created in heavy ion collisions can
be described by hydrodynamical models. After expansion and cooling, the hadrons
are created in a freeze-out. Their distribution describes the final state of
this medium. To investigate the time evolution one needs to analyze penetrating
probes, such as direct photon or dilepton observables, as these particles are
created throughout the evolution of the medium. In this paper we analyze an 1+3
dimensional analytic solution of relativistic hydrodynamics, and we calculate
dilepton transverse momentum and invariant mass distributions. We investigate
the dependence of dilepton production on time evolution parameters, such as
emission duration and equation of state. Using parameters from earlier fits of
this model to photon and hadron spectra, we compare our calculations to
measurements as well. The most important feature of this work is that dilepton
observables are calculated from an exact, analytic, 1+3D solution of
relativistic hydrodynamics that is also compatible with hadronic and direct
photon observables.


title: Using R and Bioconductor for proteomics data analysis

abstract:
  This review presents how R, the popular statistical environment and
programming language, can be used in the frame of proteomics data analysis. A
short introduction to R is given, with special emphasis on some of the features
that make R and its add-on packages a premium software for sound and
reproducible data analysis. The reader is also advised on how to find relevant
R software for proteomics. Several use cases are then presented, illustrating
data input/output, quality control, quantitative proteomics and data analysis.
Detailed code and additional links to extensive documentation are available in
the freely available companion package RforProteomics.


title:
Lang's conjecture and sharp height estimates for the elliptic curves
  $y^{2}=x^{3}+b$

abstract:
  For $E_{b}: y^{2}=x^{3}+b$, we establish Lang's conjecture on a lower bound
for the canonical height of non-torsion points along with upper and lower
bounds for the difference between the canonical and logarithmic height. In many
cases, our results are actually best-possible.


title: The Geometry of Niggli Reduction II: BGAOL -- Embedding Niggli Reduction

abstract:
  Niggli reduction can be viewed as a series of operations in a six-dimensional
space derived from the metric tensor. An implicit embedding of the space of
Niggli-reduced cells in a higher dimensional space to facilitate calculation of
distances between cells is described. This distance metric is used to create a
program, BGAOL, for Bravais lattice determination. Results from BGAOL are
compared to the results from other metric-based Bravais lattice determination
algorithms.


title:
Mikusi\'nski's Operational Calculus with Algebraic Foundations and
  Applications to Bessel Functions

abstract:
  We construct an operational calculus supported on the algebraic operational
calculus introduced by Bengochea and Verde. With this operational calculus we
study the solution of certain Bessel type equations.


title: Evolution of the 1919 Ejecta of V605 Aquilae

abstract:
  New imaging of V605 Aql, was obtained in 2009 with HST/WFPC2, which had a
nova-like outburst in 1919, and is located at the center of the planetary
nebula (PN), Abell 58. This event has long been ascribed to a final helium
shell flash, but it has been suggested recently that it may instead have been
an ONe nova. The new images provide an 18 year baseline for the expansion of
the ejecta from the 1919 event. In addition, the central star has been directly
detected in the visible for the first time since 1923, when it faded from sight
due to obscuration by dust. The expansion of the ejecta has a velocity of ~200
km/s, and an angular expansion rate of ~10 mas/yr, consistent with a 1919
ejection. This implies a geometric distance of 4.6 kpc for V605 Aql, consistent
with previous estimates. The gas mass in the central knot of ejecta was
previously estimated to be 5 x 10^-5 M(Sun). It is estimated that warm dust
associated with this gas has a mass of ~10^-5 M(Sun). There is also evidence
for a significant amount, 10^-3 M(Sun), of cold (75 K) dust, which may be
associated with its PN. The knot ejected in 1919 is asymmetrical and is
approximately aligned with the asymmetry of the surrounding PN. Polarimetric
imaging was obtained to investigate whether the 2001 spectrum of V605 Aql was
obtained primarily in scattered light from dust in the central knot, but the
signal-to-noise in the data was insufficient to measure the level of
polarization.


title: The lithium isotopic ratio in very metal-poor stars

abstract:
  Un-evolved, very metal-poor stars are the most important tracers of the
cosmic abundance of lithium in the early universe. Combining the standard Big
Bang nucleosynthesis model with Galactic production through cosmic ray
spallation, these stars at [Fe/H]<-2 are expected to show an undetectably small
6Li/7Li isotopic signature. Evidence to the contrary may necessitate an
additional pre-galactic production source or a revision of the standard model
of Big Bang nucleosynthesis. We revisit the isotopic analysis of four halo
stars, two with claimed 6Li-detections in the literature, to investigate the
influence of improved model atmospheres and line formation treatment. For the
first time, a combined 3D, NLTE (non-local thermodynamic equilibrium) modelling
technique for Li, Na, and Ca lines is utilised to constrain the intrinsic
line-broadening and to determine the Li isotopic ratio. We discuss the
influence of 3D NLTE effects on line profile shapes and assess the realism of
our modelling using the Ca excitation and ionisation balance. By accounting for
NLTE line formation in realistic 3D hydrodynamical model atmospheres, we can
model the Li resonance line and other neutral lines with a consistency that is
superior to LTE, with no need for additional line asymmetry caused by the
presence of 6Li. Contrary to the results from 1D and 3D LTE modelling, no star
in our sample has a significant 2-sigma detection of the lighter isotope in
NLTE. Over a large parameter space, NLTE modelling systematically reduces the
best-fit Li isotopic ratios by up to five percentage points. As a bi-product,
we also present the first ever 3D NLTE Ca and Na abundances of halo stars,
which reveal significant departures from LTE. The observational support for a
significant and non-standard 6Li production source in the early universe is
substantially weakened by our findings.


title: Path Integrals and Reality

abstract:
  We define the idea of {\it real path quantum theory}, a realist
generalisation of quantum theory in which it is postulated that the
configuration space path actually followed by a closed quantum system is
probabilistically chosen. This is done a postulate defining probabilities for
paths, which we propose are determined by an expression involving path
amplitudes and a distance function that quantifies path separation. We suggest
a possible form for a path probability postulate and explore possible choices
of distance function, including choices suitable for Lorentz or generally
covariant versions of real path quantum theory. We set out toy models of
quantum interferometry and show that in these models the probability postulate
and specific distance functions do indeed give a physically sensible path
ontology. These functions can be chosen so as to predict quantum interference
for interference of microscopic quantum systems and the failure of interference
for macroscopic quantum systems. More generally, they predict interference when
the beams are close, and its failure when they are far apart, as determined by
the distance function. If taken seriously in its present relatively
unconstrained form, real path quantum theory thus motivates experimental tests
of quantum interference in all unexplored regimes defined by potentially
physically interesting parameters, including the mass of the beam object, the
beam separation distance, the beam separation time, and many others. We discuss
open questions raised by these ideas.


title: Almost local generation of EPR entanglement in non-equilibrium

abstract:
  The generation of entanglement is studied in a minimal model consisting of
two independent Gaussian parties embedded in a common heat bath and subject to
local control signals. Neither the reservoir alone nor the external driving can
induce quantum non-locality but only the cooperative impact of both in
non-equilibrium. It is shown that this corresponds to a dynamical symmetry
breaking between the modes. By applying optimal control protocols substantial
entanglement is generated even for single-site control and at higher
temperatures and is preserved after the control is switched off.


title:
Physical interpretation of the dressed Polyakov loop in the
  Nambu--Jona-Lasinio model

abstract:
  We investigate the rapid rise of the dressed Polyakov loop in the
Nambu--Jona-Lasinio (NJL) model as a function of temperature. In QCD such a
behaviour is interpreted as a confinement- deconfinement phase transition.
However, we demonstrate that in the NJL model this is simply a remnant of the
chiral transition.


title: Reinforcement Learning for the Soccer Dribbling Task

abstract:
  We propose a reinforcement learning solution to the \emph{soccer dribbling
task}, a scenario in which a soccer agent has to go from the beginning to the
end of a region keeping possession of the ball, as an adversary attempts to
gain possession. While the adversary uses a stationary policy, the dribbler
learns the best action to take at each decision point. After defining
meaningful variables to represent the state space, and high-level macro-actions
to incorporate domain knowledge, we describe our application of the
reinforcement learning algorithm \emph{Sarsa} with CMAC for function
approximation. Our experiments show that, after the training period, the
dribbler is able to accomplish its task against a strong adversary around 58%
of the time.


title: Mathematical Analysis of Temperature Accelerated Dynamics

abstract:
  We give a mathematical framework for temperature accelerated dynamics (TAD),
an algorithm proposed by M.R. S{\o}rensen and A.F. Voter to efficiently
generate metastable stochastic dynamics. Using the notion of quasistationary
distributions, we propose some modifications to TAD. Then considering the
modified algorithm in an idealized setting, we show how TAD can be made
mathematically rigorous.


title:
Intensity landscape and the possibility of magic trapping of alkali
  Rydberg atoms in infrared optical lattices

abstract:
  Motivated by compelling advances in manipulating cold Rydberg (Ry) atoms in
optical traps, we consider the effect of large extent of Ry electron wave
function on trapping potentials. We find that when the Ry orbit lies outside
inflection points in laser intensity landscape, the atom can stably reside in
laser intensity maxima. Effectively, the free-electron AC polarizability of Ry
electron is modulated by intensity landscape and can accept both positive and
negative values. We apply these insights to determining magic wavelengths for
Ry-ground-state transitions for alkali atoms trapped in infrared optical
lattices. We find magic wavelengths to be around 10 $\mu \mathrm{m}$, with
exact values that depend on Ry state quantum numbers.


title:
Transmission Eigenvalues for a Class of Non-Compactly Supported
  Potentials

abstract:
  Let $\Omega\subseteq\mathbb R^n$ be a non-empty open set for which the
Sobolev embedding $H_0^2(\Omega)\longrightarrow L^2(\Omega)$ is compact, and
let $V\in L^\infty(\Omega)$ be a potential taking only positive real values and
satisfying the asymptotics
$V(\cdot)\asymp\left\langle\cdot\right\rangle^{-\alpha}$ for some
$\alpha\in\left]3,\infty\right[$. We establish the discreteness of the set of
real transmission eigenvalues for both Schr\"odinger and Helmholtz scattering
with these potentials.


title:
Exciton Dynamics in Carbon Nanotubes: From the Luttinger Liquid to
  Harmonic Oscillators

abstract:
  We show that the absorption spectrum in semiconducting nanotubes can be
determined using the bosonization technique combined with mean-field theory and
a harmonic approximation. Our results indicate that a multiple band
semiconducting nanotube reduces to a system of weakly coupled harmonic
oscillators. Additionally, the quasiparticle nature of the electron and hole
that comprise an optical exciton emerges naturally from the bosonized model.


title: Subgroups of p-divisible groups and centralizers in symmetric groups

abstract:
  For cohomology theories closely related to Morava E-theory, we provide an
algebro-geometric interpretation of the cohomology of groups that arise as
centralizers of tuples of commuting elements inside of symmetric groups. The
interpretation is given in terms of the connected components of the scheme that
classifies subgroup schemes of a particular p-divisible group.


title:
Atomic magnetic resonance induced by amplitude-, frequency-, or
  polarization-modulated light

abstract:
  In recent years diode laser sources have become widespread and reliable tools
in magneto-optical spectroscopy. In particular, laser-driven atomic
magnetometers have found a wide range of practical applications. More recently,
so-called magnetically silent variants of atomic magnetometers have been
developed. While in conventional magnetometers the magnetic resonance
transitions between atomic sublevels are phase-coherently driven by a weak
oscillating magnetic field, silent magnetometers use schemes in which either
the frequency (FM) or the amplitude (AM) of the light beam is modulated. Here
we present a theoretical model that yields algebraic expressions for the
parameters of the multiple resonances that occur when either amplitude-,
frequency- or polarization-modulated light of circular polarization is used to
drive the magnetic resonance transition in a transverse magnetic field. The
relative magnitudes of the resonances that are observed in the transmitted
light intensity at harmonic m of the Larmor frequency \omega_L (either by DC or
phase sensitive detection at harmonics q of the modulation frequency
\omega_mod) of the transmitted light are expressed in terms of the Fourier
coefficients of the modulation function. Our approach is based on an atomic
multipole moment representation that is valid for spin-oriented atomic states
with arbitrary angular momentum F in the low light power limit. We find
excellent quantitative agreement with an experimental case study using
(square-wave) amplitude-modulated (AM) light.


title:
Index for Assessing Water Trophic Status in Semi-Enclosed Cuban Bays.
  Case Study: Cienfuegos Bay

abstract:
  This paper aims at contributing to the coastal environmental management by
developing a new trophic status index of the water (TSIW). The index is
tailored to semi-enclosed bays with estuarine characteristic like the
Cienfuegos bay in Cuba. We also propose pressure indicators related to
exporting and assimilation capacities as a tool to assess the vulnerability of
the system to eutrophication. The TSIW is based on response indicators to
eutrophication processes showing correspondence with the predefined pressure
indicators and previous reports on water quality. Thus, the proposed trophic
status index is a reliable scientific tool to measure the current stage of the
water quality and to establish a baseline for further studies.


title: Frozen photons in Jaynes Cummings arrays

abstract:
  We study the origin of "frozen" states in coupled Jaynes-Cummings-Hubbard
arrays in the presence of losses. For the case of half the array initially
populated with photons while the other half is left empty we show the emergence
of self-localized photon or "frozen" states for specific values of the local
atom-photon coupling. We analyze the dynamics in the quantum regime and
discover important additional features appear not captured by a semiclassical
treatment, which we analyze for different array sizes and filling fractions. We
trace the origin of this interaction-induced photon "freezing" to the
suppression of excitation of propagating modes in the system at large
interaction strengths. We discuss in detail the possibility to experimentally
probe the relevant transition by analyzing the emitted photon correlations. We
find a strong signature of the effect in the emitted photons statistics.


title: Polynomial Bounds for the Grid-Minor Theorem

abstract:
  One of the key results in Robertson and Seymour's seminal work on graph
minors is the Grid-Minor Theorem (also called the Excluded Grid Theorem). The
theorem states that for every grid $H$, every graph whose treewidth is large
enough relative to $|V(H)|$ contains $H$ as a minor. This theorem has found
many applications in graph theory and algorithms. Let $f(k)$ denote the largest
value such that every graph of treewidth $k$ contains a grid minor of size
$(f(k)\times f(k))$. The best previous quantitative bound, due to recent work
of Kawarabayashi and Kobayashi, and Leaf and Seymour, shows that
$f(k)=\Omega(\sqrt{\log k/\log \log k})$. In contrast, the best known upper
bound implies that $f(k) = O(\sqrt{k/\log k})$. In this paper we obtain the
first polynomial relationship between treewidth and grid minor size by showing
that $f(k)=\Omega(k^{\delta})$ for some fixed constant $\delta > 0$, and
describe a randomized algorithm, whose running time is polynomial in $|V(G)|$
and $k$, that with high probability finds a model of such a grid minor in $G$.


title:
Thickness-induced violation of de Haas-van Alphen effect through exact
  analytical solutions at a one-electron and a one-Composite Fermion level

abstract:
  A systematic study of the energetics of electrons in an interface in a
magnetic field is reported with exact analytical calculations based on a Landau
Level (LL) picture, by serious consideration of the finite thickness of the
Quantum Well (QW). The approach is physically transparent and subtly different
in its line of reasoning from standard methods avoiding any semi-classical
approximation. We find "internal" phase transitions (at partial LL filling) for
magnetisation and susceptibility that are not captured by other approaches and
that give rise to nontrivial violations of the standard de Haas-van Alphen
periods, in a manner that reproduces the exact quantal astrophysical behaviours
in the limit of full three-dimensional (3D) space. Upon inclusion of Zeeman
splitting, additional features are also found, such as global energy minima
originating from the interplay of QW, Zeeman and LL Physics, while a
corresponding calculation in a Composite Fermion picture with {\Lambda}-Levels,
leads to new predictions on magnetic properties of an interacting electron
liquid. By pursuing the same line of reasoning for a topologically nontrivial
system with a relativistic spectrum, we find evidence that similar effects
might be operative in the dimensionality crossover of 3D strong topological
insulators to 2D topological insulator quantum wells.


title: Generalization of the Nualart-Peccati criterion

abstract:
  The celebrated Nualart-Peccati criterion [Ann. Probab. 33 (2005) 177-193]
ensures the convergence in distribution toward a standard Gaussian random
variable $N$ of a given sequence $\{X_n\}_{n\ge1}$ of multiple Wiener-It\^{o}
integrals of fixed order, if $\mathbb {E}[X_n^2]\to1$ and $\mathbb
{E}[X_n^4]\to \mathbb {E}[N^4]=3$. Since its appearance in 2005, the natural
question of ascertaining which other moments can replace the fourth moment in
the above criterion has remained entirely open. Based on the technique recently
introduced in [J. Funct. Anal. 266 (2014) 2341-2359], we settle this problem
and establish that the convergence of any even moment, greater than four, to
the corresponding moment of the standard Gaussian distribution, guarantees the
central convergence. As a by-product, we provide many new moment inequalities
for multiple Wiener-It\^{o} integrals. For instance, if $X$ is a normalized
multiple Wiener-It\^{o} integral of order greater than one, \[\forall
k\ge2,\qquad \mathbb {E}\bigl[X^{2k}\bigr]>\mathbb {E}
\bigl[N^{2k}\bigr]=(2k-1)!!.\]


title: Cooperation dilemma in finite populations under fluctuating environments

abstract:
  We present a novel approach allowing the study of rare events like fixation
under fluctuating environments, modeled as extrinsic noise, in evolutionary
processes characterized by the dominance of one species. Our treatment consists
of mapping the system onto an auxiliary model, exhibiting metastable species
coexistence, that can be analyzed semiclassically. This approach enables us to
study the interplay between extrinsic and demographic noise on the statistics
of interest. We illustrate our theory by considering the paradigmatic
prisoner's dilemma game whose evolution is described by the probability that
cooperators fixate the population and replace all defectors. We analytically
and numerically demonstrate that extrinsic noise may drastically enhance the
cooperation fixation probability and even change its functional dependence on
the population size. These results, which generalize earlier works in
population genetics, indicate that extrinsic noise may help sustain and promote
a much higher level of cooperation than static settings.


title:
Comparison of different nonlinear solvers for 2D time-implicit stellar
  hydrodynamics

abstract:
  Time-implicit schemes are attractive since they allow numerical time steps
that are much larger than those permitted by the Courant-Friedrich-Lewy
criterion characterizing time-explicit methods. This advantage comes, however,
with a cost: the solution of a system of nonlinear equations is required at
each time step. In this work, the nonlinear system results from the
discretization of the hydrodynamical equations with the Crank-Nicholson scheme.
We compare the cost of different methods, based on Newton-Raphson iterations,
to solve this nonlinear system, and benchmark their performances against
time-explicit schemes. Since our general scientific objective is to model
stellar interiors, we use as test cases two realistic models for the convective
envelope of a red giant and a young Sun. Focusing on 2D simulations, we show
that the best performances are obtained with the quasi-Newton method proposed
by Broyden. Another important concern is the accuracy of implicit calculations.
Based on the study of an idealized problem, namely the advection of a single
vortex by a uniform flow, we show that there are two aspects: i) the nonlinear
solver has to be accurate enough to resolve the truncation error of the
numerical discretization, and ii) the time step has be small enough to resolve
the advection of eddies. We show that with these two conditions fulfilled, our
implicit methods exhibit similar accuracy to time-explicit schemes, which have
lower values for the time step and higher computational costs. Finally, we
discuss in the conclusion the applicability of these methods to fully implicit
3D calculations.

categories: astro-ph.SR cs.NA math.NA physics.comp-ph


title: Analysis of Uq(sl(m+1))-symmetries on quantum n-spaces

abstract:
  In this paper, the module-algebra structures of $U_q(sl(m+1))$ on the quantum
$n$-space $A_q(n)$ are studied. We characterize all module-algebra structures
of $U_q(sl(m+1))$ on $A_q(2)$ and $A_q(3)$ when $m\geq 2$. The module-algebra
structures of $U_q(sl(m+1))$ on $A_q(n)$ are also considered for any $n\geq 4$.


title: Controlling the dynamic range of a Josephson parametric amplifier

abstract:
  One of the central challenges in the development of parametric amplifiers is
the control of the dynamic range relative to its gain and bandwidth, which
typically limits quantum limited amplification to signals which contain only a
few photons per inverse bandwidth. Here, we discuss the control of the dynamic
range of Josephson parametric amplifiers by using Josephson junction arrays. We
discuss gain, bandwidth, noise, and dynamic range properties of both a
transmission line and a lumped element based parametric amplifier. Based on
these investigations we derive useful design criteria, which may find broad
application in the development of practical parametric amplifiers.


title: Trampoline metamaterial: Local resonance enhancement by springboards

abstract:
  We investigate the dispersion characteristics of locally resonant elastic
metamaterials formed by the erection of pillars on the solid regions in a plate
patterned by a periodic array of holes. We show that these solid regions
effectively act as springboards leading to an enhanced resonance behavior by
the pillars when compared to the nominal case of pillars with no holes. This
local resonance amplification phenomenon, which we define as the "trampoline
effect", is shown to cause subwavelength band gaps to increase in size by up to
a factor of 4. This outcome facilitates the utilization of subwavelength
metamaterial properties over exceedingly broad frequency ranges.


title:
Effects of diffuse background emission and source crowding on
  photometric completeness in Spitzer Space Telescope IRAC surveys: The GLIMPSE
  Catalogs and Archives

abstract:
  We characterize the completeness of point source lists from Spitzer Space
Telescope surveys in the four Infrared Array Camera (IRAC) bandpasses,
emphasizing the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire
(GLIMPSE) programs (GLIMPSE I, II, 3D, 360; Deep GLIMPSE) and their resulting
point source Catalogs and Archives. The analysis separately addresses effects
of incompleteness resulting from high diffuse background emission and
incompleteness resulting from point source confusion (i.e., crowding). An
artificial star addition and extraction analysis demonstrates that completeness
is strongly dependent on local background brightness and structure, with
high-surface-brightness regions suffering up to five magnitudes of reduced
sensitivity to point sources. This effect is most pronounced at the IRAC 5.8
and 8.0 microns bands where UV-excited PAH emission produces bright, complex
structures (photodissociation regions; PDRs). With regard to diffuse background
effects, we provide the completeness as a function of stellar magnitude and
diffuse background level in graphical and tabular formats. These data are
suitable for estimating completeness in the low-source-density limit in any of
the four IRAC bands in GLIMPSE Catalogs and Archives and some other Spitzer
IRAC programs that employ similar observational strategies and are processed by
the GLIMPSE pipeline. Point source incompleteness is primarily a consequence of
structure in the diffuse background emission rather than photon noise. With
regard to source confusion in the high-source-density regions of the Galactic
Plane, we provide figures illustrating the 90% completeness levels as a
function of point source density at each band. (Slightly abridged)


title: Asteroseismic surface gravity for evolved stars

abstract:
  Context: Asteroseismic surface gravity values can be of importance in
determining spectroscopic stellar parameters. The independent log(g) value from
asteroseismology can be used as a fixed value in the spectroscopic analysis to
reduce uncertainties due to the fact that log(g) and effective temperature can
not be determined independently from spectra. Since 2012, a combined analysis
of seismically and spectroscopically derived stellar properties is ongoing for
a large survey with SDSS/APOGEE and Kepler. Therefore, knowledge of any
potential biases and uncertainties in asteroseismic log(g) values is now
becoming important. Aims: The seismic parameter needed to derive log(g) is the
frequency of maximum oscillation power (nu_max). Here, we investigate the
influence of nu_max derived with different methods on the derived log(g)
values. The large frequency separation between modes of the same degree and
consecutive radial orders (Dnu) is often used as an additional constraint for
the determination of log(g). Additionally, we checked the influence of small
corrections applied to Dnu on the derived values of log(g). Methods We use
methods extensively described in the literature to determine nu_max and Dnu
together with seismic scaling relations and grid-based modeling to derive
log(g). Results: We find that different approaches to derive oscillation
parameters give results for log(g) with small, but different, biases for
red-clump and red-giant-branch stars. These biases are well within the quoted
uncertainties of ~0.01 dex (cgs). Corrections suggested in the literature to
the Dnu scaling relation have no significant effect on log(g). However somewhat
unexpectedly, method specific solar reference values induce biases of the order
of the uncertainties, which is not the case when canonical solar reference
values are used.


title: Minimal Decaying Dark Matter and the LHC

abstract:
  We consider a minimal Dark Matter model with just two additional states, a
Dark Matter Majorana fermion and a colored or electroweakly charged scalar,
without introducing any symmetry to stabilize the DM state. We identify the
parameter region where an indirect DM signal would be within the reach of
future observations and the DM relic density generated fits the observations.
We find in this way two possible regions in the parameter space, corresponding
to a FIMP/SuperWIMP or a WIMP DM. We point out the different collider signals
of this scenario and how it will be possible to measure the different couplings
in case of a combined detection.


title: Decay of correlation for random intermittent maps

abstract:
  We study a class of random transformations built over finitely many
intermittent maps sharing a common indifferent fixed point. Using a Young-tower
technique, we show that the map with the fastest relaxation rate dominates the
asymptotics. In particular, we prove that the rate of correlation decay for the
annealed dynamics of the random map is the same as the sharp rate of
correlation decay for the map with the fastest relaxation rate.


title: Thermodynamics of Quantum-Jump-Conditioned Feedback Control

abstract:
  We consider open quantum systems weakly coupled to thermal reservoirs and
subjected to quantum feedback operations triggered with or without delay by
monitored quantum jumps. We establish a thermodynamic description of such
system and analyze how the first and second law of thermodynamics are modified
by the feedback. We apply our formalism to study the efficiency of a qubit
subjected to a quantum feedback control and operating as a heat pump between
two reservoirs. We also demonstrate that quantum feedbacks can be used to
stabilize coherences in nonequilibrium stationary states which in some cases
may even become pure quantum states.


title: Electric Field Driven Torque in ATP Synthase

abstract:
  Fo-ATP synthase (Fo) is a rotary motor that converts potential energy from
ions, usually protons, moving from high- to low-potential sides of a membrane
into torque and rotary motion. Here we propose a mechanism whereby electric
fields emanating from the proton entry and exit channels act on asymmetric
charge distributions in the c-ring, due to protonated and deprotonated sites,
and drive it to rotate. The model predicts a scaling between time-averaged
torque and proton motive force, which can be hindered by mutations that
adversely affect the channels. The torque created by the c-ring of Fo drives
the gamma-subunit to rotate within the ATP-producing complex (F1) overcoming,
with the aid of thermal fluctuations, an opposing torque that rises and falls
with angular position. Using the analogy with thermal Brownian motion of a
particle in a tilted washboard potential, we compute ATP production rates vs.
proton motive force. The latter shows a minimum, needed to drive ATP
production, which scales inversely with the number of proton binding sites on
the c-ring.


title:
Delay of light in an optical bottle resonator with nanoscale radius
  variation: dispersionless, broadband, and low-loss

abstract:
  It is shown theoretically that an optical bottle resonator with a nanoscale
radius variation can perform a multi-nanosecond long dispersionless delay of
light in a nanometer-order bandwidth with minimal losses. Experimentally, a 3
mm long resonator with a 2.8 nm deep semi-parabolic radius variation is
fabricated from a 19 micron radius silica fiber with a sub-angstrom precision.
In excellent agreement with theory, the resonator exhibits the
impedance-matched 2.58 ns (3 bytes) delay of 100 ps pulses with 0.44 dB/ns
intrinsic loss. This is a miniature slow light delay line with the record large
delay time, record small transmission loss, dispersion, and effective speed of
light.


title:
Polarization radiation of vortex electrons with large orbital angular
  momentum

abstract:
  Vortex electrons, - freely propagating electrons whose wavefunction has
helical wavefronts, - could become a novel tool in the physics of
electromagnetic radiation. They carry a non-zero intrinsic orbital angular
momentum (OAM) $\ell$ with respect to the propagation axis and, for \ell \gg 1,
a large OAM-induced magnetic moment, \mu ~ \ell \mu_B (\mu_B is the Bohr
magneton), which influences the radiation of electromagnetic waves. Here, we
consider in detail the OAM-induced effects by such electrons in two forms of
polarization radiation, namely in Cherenkov radiation and transition radiation.
Thanks to the large \ell, we can neglect quantum or spin-induced effects, which
are of the order of \hbar \omega/E_e \ll 1, but retain the magnetic moment
contribution \ell \hbar \omega/E_e \lesssim 1, which makes the quasiclassical
approach to polarization radiation applicable. We discuss the magnetic moment
contribution to polarization radiation, which has never been experimentally
observed, and study how its visibility depends on the kinematical parameters
and the medium permittivity. In particular, it is shown that this contribution
can, in principle, be detected in azimuthally non-symmetrical problems, for
example when vortex electrons obliquely cross a metallic screen (transition
radiation) or move nearby it (diffraction radiation). We predict a left-right
angular asymmetry of the transition radiation (in the plane where the charge
radiation distributions would stay symmetric), which appears due to an
effective interference between the charge radiation field and the magnetic
moment one. Numerical values of this asymmetry for vortex electrons with E_e =
300keV and \ell = O(100-1000) are O(0.1-1%), and we argue that this effect
could be detected with existing technology. The finite conductivity of the
target and frequency dispersion play the crucial roles in these predictions.

categories: physics.optics hep-ph physics.acc-ph quant-ph


title:
Geometry of moduli spaces of meromorphic connections on curves, Stokes
  data, wild nonabelian Hodge theory, hyperkahler manifolds, isomonodromic
  deformations, Painleve equations, and relations to Lie theory

abstract: Summary of main work 1999-2012


title: Symmetric cubic surfaces and G_2 character varieties

abstract:
  We will consider a two dimensional "symmetric" subfamily of the four
dimensional family of Fricke cubic surfaces. The main result is that such
symmetric cubic surfaces arise as character varieties for the exceptional group
of type G_2. Further, this symmetric family will be related to the fixed points
of the triality automorphism of Spin(8), and an example involving the finite
simple group of order 6048 inside G_2 will be considered.


title: Paired galaxies with different activity levels and their supernovae

abstract:
  We investigate the influence of close neighbor galaxies on the properties of
supernovae (SNe) and their host galaxies using 56 SNe located in pairs of
galaxies with different levels of star formation (SF) and nuclear activity. The
statistical study of SN hosts shows that there is no significant difference
between morphologies of hosts in our sample and the larger general sample of SN
hosts in the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). The mean
distance of type II SNe from nuclei of hosts is greater by about a factor of 2
than that of type Ibc SNe. The distributions and mean distances of SNe are
consistent with previous results compiled with the larger sample. For the first
time it is shown that SNe Ibc are located in pairs with significantly smaller
difference of radial velocities between components than pairs containing SNe Ia
and II. We consider this as a result of higher star formation rate (SFR) of
these closer systems of galaxies. SN types are not correlated with the
luminosity ratio of host and neighbor galaxies in pairs. The orientation of SNe
with respect to the preferred direction toward neighbor galaxy is found to be
isotropic and independent of kinematical properties of the galaxy pair.


title: On the Coloring of Pseudoknots

abstract:
  Pseudodiagrams are diagrams of knots where some information about which
strand goes over/under at certain crossings may be missing. Pseudoknots are
equivalence classes of pseudodiagrams, with equivalence defined by a class of
Reidemeister-type moves. In this paper, we introduce two natural extensions of
classical knot colorability to this broader class of knot-like objects. We use
these definitions to define the determinant of a pseudoknot (i.e. the
pseudodeterminant) that agrees with the classical determinant for classical
knots. Moreover, we extend Conway notation to pseudoknots to facilitate the
investigation of families of pseudoknots and links. The general formulae for
pseudodeterminants of pseudoknot families may then be used as a criterion for
p-colorability of pseudoknots.


title: Low-degree planar monomials in characteristic two

abstract:
  Planar functions over finite fields give rise to finite projective planes and
other combinatorial objects. They exist only in odd characteristic, but
recently Zhou introduced an even characteristic analogue which has similar
applications. In this paper we determine all planar functions on F_q of the
form c-->uc^t, where q is a power of 2, t is an integer with 0<t<=q^{1/4}, and
u is a nonzero element of F_q. This settles and sharpens a conjecture of
Schmidt and Zhou.


title: Microscopic observation of magnon bound states and their dynamics

abstract:
  More than eighty years ago, H. Bethe pointed out the existence of bound
states of elementary spin waves in one-dimensional quantum magnets. To date,
identifying signatures of such magnon bound states has remained a subject of
intense theoretical research while their detection has proved challenging for
experiments. Ultracold atoms offer an ideal setting to reveal such bound states
by tracking the spin dynamics after a local quantum quench with single-spin and
single-site resolution. Here we report on the direct observation of two-magnon
bound states using in-situ correlation measurements in a one-dimensional
Heisenberg spin chain realized with ultracold bosonic atoms in an optical
lattice. We observe the quantum walk of free and bound magnon states through
time-resolved measurements of the two spin impurities. The increased effective
mass of the compound magnon state results in slower spin dynamics as compared
to single magnon excitations. In our measurements, we also determine the decay
time of bound magnons, which is most likely limited by scattering on thermal
fluctuations in the system. Our results open a new pathway for studying
fundamental properties of quantum magnets and, more generally, properties of
interacting impurities in quantum many-body systems.


title: Similarity flow of a neutral scalar coupled to a fixed source

abstract:
  A neutral scalar meson interacting with a fixed isoscalar nucleon is evolved
according to the similarity renormalization group. The fixed source ends up
being too singular and an appropriately dressed static source arises from the
similarity flow. The fixed source is dressed by a virtual cloud of mesons
extending out past the inverse meson mass according to the Yukawa potential.
For low energies the source produces a Yukawa mean field which decouples from
the remaining meson field fluctuations. The renormalization group procedure for
effective particles is also illustrated for this fixed-source model.


title: Marginally trapped surfaces in spaces of oriented geodesics

abstract:
  We investigate the geometric properties of marginally trapped surfaces
(surfaces which have null mean curvature vector) in the spaces of oriented
geodesics of Euclidean 3-space and hyperbolic 3-space, endowed with their
canonical neutral Kaehler structures.
  We prove that every rank one surface in these four manifolds is marginally
trapped. In the Euclidean case we show that Lagrangian rotationally symmetric
sections are marginally trapped and construct an explicit family of marginally
trapped Lagrangian tori.
  In the hyperbolic case we explore the relationship between marginally trapped
and Weingarten surfaces, and construct examples of marginally trapped surfaces
with various properties.


title:
Some New Hermite-Hadamard type inequalities for s-geometrically convex
  functions and their applications

abstract:
  In this paper, some new integral inequalities of Hermite-Hadamard type
related to the s-geometrically convex functions are established and some
applications to special means of positive real numbers are also given.


title:
Tunable Quantum Temperature Oscillations in Graphene and Carbon
  Nanoribbons

abstract:
  We investigate the local electron temperature distribution in carbon
nano-ribbon (CNR) and graphene junctions subject to an applied thermal
gradient. Using a realistic model of a scanning thermal microscope, we predict
quantum temperature oscillations whose wavelength is related to that of Friedel
oscillations. Experimentally, this wavelength can be tuned over several orders
of magnitude by gating/doping, bringing quantum temperature oscillations within
reach of the spatial resolution of existing measurement techniques.