title: A Fundamental Solution to the CCC equation

abstract:
  We display a simple solution to the Penrose CCC scenario. For this solution
we chose for the late stages of the previous aeon a FRW, k=0, universe with a
both a cosmological constant and radiation (no mass) while for the early stages
of the 'present' aeon we have again a FRW universe, k=0, with the same
cosmological constant and again with radiation but with mass not yet present.
The Penrose conditions force the parameters describing the radiation of the
former and present aeons to be equal and the transition metric in the overlap
region turns out to be flat. We further study how different rest-mass zero
fields transition between the different conformally related regions. These
(test) fields appears to easily allow perturbations of the geometry within the
CCC scenario.


title: On the use of human mobility proxy for the modeling of epidemics

abstract:
  Human mobility is a key component of large-scale spatial-transmission models
of infectious diseases. Correctly modeling and quantifying human mobility is
critical for improving epidemic control policies, but may be hindered by
incomplete data in some regions of the world. Here we explore the opportunity
of using proxy data or models for individual mobility to describe commuting
movements and predict the diffusion of infectious disease. We consider three
European countries and the corresponding commuting networks at different
resolution scales obtained from official census surveys, from proxy data for
human mobility extracted from mobile phone call records, and from the radiation
model calibrated with census data. Metapopulation models defined on the three
countries and integrating the different mobility layers are compared in terms
of epidemic observables. We show that commuting networks from mobile phone data
well capture the empirical commuting patterns, accounting for more than 87% of
the total fluxes. The distributions of commuting fluxes per link from both
sources of data - mobile phones and census - are similar and highly correlated,
however a systematic overestimation of commuting traffic in the mobile phone
data is observed. This leads to epidemics that spread faster than on census
commuting networks, however preserving the order of infection of newly infected
locations. Match in the epidemic invasion pattern is sensitive to initial
conditions: the radiation model shows higher accuracy with respect to mobile
phone data when the seed is central in the network, while the mobile phone
proxy performs better for epidemics seeded in peripheral locations. Results
suggest that different proxies can be used to approximate commuting patterns
across different resolution scales in spatial epidemic simulations, in light of
the desired accuracy in the epidemic outcome under study.


title:
Renormalization group flow of Ho\v{r}ava-Lifshitz gravity at low
  energies

abstract:
  The functional renormalization group equation for projectable
Ho\v{r}ava-Lifshitz gravity is used to derive the non-perturbative beta
functions for the Newton's constant, cosmological constant and anisotropy
parameter. The resulting coupled differential equations are studied in detail
and exemplary RG trajectories are constructed numerically. The beta functions
possess a non-Gaussian fixed point and a one-parameter family of Gaussian fixed
points. One of the Gaussian fixed points corresponds to the Einstein-Hilbert
action with vanishing cosmological constant and constitutes a saddle point with
one IR-attractive direction. For RG trajectories dragged into this fixed point
at low energies diffeomorphism invariance is restored. The emergence of general
relativity from Ho\v{r}ava-Lifshitz gravity can thus be understood as a
crossover-phenomenon where the IR behavior of the theory is controlled by this
Gaussian fixed point. In particular RG trajectories with a tiny positive
cosmological constant also come with an anisotropy parameter which is
compatible with experimental constraints, providing a mechanism for the
approximate restoration of diffeomorphism invariance in the IR. The
non-Gaussian fixed point is UV-attractive in all three coupling constants. Most
likely, this fixed point is the imprint of Asymptotic Safety at the level of
Ho\v{r}ava-Lifshitz gravity.


title:
Generation of Projector Augmented-Wave atomic data: a 71 elements
  validated table in the XML format

abstract:
  A Projector Augmented Wave (PAW) atomic data file is needed to be generated
for each element, and plays in the PAW method the role of the pseudopotential
file for norm-conserving (NC) or ultra-soft (US) plane wave calculations. In
this paper, we present a review on how to obtain these data as well as results
concerning their accuracy, their transferability and their efficiency for bulk
solids. Following \cite{Lejaeghere}, we propose a new criterium to test PAW
atomic data and we provide a new table written in a XML format potentially
readable by every PAW electronic structure code.


title: Superelliptical laws for complex networks

abstract:
  All dynamical systems of biological interest--be they food webs, regulation
of genes, or contacts between healthy and infectious individuals--have complex
network structure. Wigner's semicircular law and Girko's circular law describe
the eigenvalues of systems whose structure is a fully connected network.
However, these laws fail for systems with complex network structure. Here we
show that in these cases the eigenvalues are described by superellipses. We
also develop a new method to analytically estimate the dominant eigenvalue of
complex networks.


title: Adopting level set theory based algorithms to segment human ear

abstract:
  Human identification has always been a topic that interested researchers
around the world. Biometric methods are found to be more effective and much
easier for the users than the traditional identification methods like keys,
smart cards and passwords. Unlike with the traditional methods, with biometric
methods the data acquisition is most of the times passive, which means the
users do not take active part in data acquisition. Data acquisition can be
performed using cameras, scanners or sensors. Human physiological biometrics
such as face, eye and ear are good candidates for uniquely identifying an
individual. However, human ear scores over face and eye because of certain
advantages it has over face. The most challenging phase in human identification
based on ear biometric is the segmentation of the ear image from the captured
image which may contain many unwanted details. In this work, PDE based image
processing techniques are used to segment out the ear image. Level Set Theory
based image processing is employed to obtain the contour of the ear image. A
few Level set algorithms are compared for their efficiency in segmenting test
ear images.


title: A note on the Chern-Simons-Dirac equations in the Coulomb Gauge

abstract:
  We prove that the Chern-Simons-Dirac equations in the Coulomb gauge are
locally well-posed from initial data in H^s with s > 1/4 . To study nonlinear
Wave or Dirac equations at this regularity generally requires the presence of
null structure. The novel point here is that we make no use of the null
structure of the system. Instead we exploit the additional elliptic structure
in the Coulomb gauge together with the bilinear Strichartz estimates of
Klainerman-Tataru.


title:
Universal Quantum Computation With Majorana Fermion Edge Modes Through
  Microwave Spectroscopy Of Quasi-1D Cold Gases In Optical Lattices

abstract:
  We describe how microwave spectroscopy of cold fermions in quasi-1D traps can
be used to detect, manipulate, and entangle exotic non-local qbits associated
with "Majorana" edge modes. We present different approaches to generate the
p-wave superfluidity which is responsible for these topological zero-energy
edge modes. We find that the edge modes have clear signatures in the microwave
spectrum, and that the line shape distinguishes between the degenerate states
of a qbit encoded in these edge modes. Moreover, the microwaves rotate the
system in its degenerate ground-state manifold. We use these rotations to
implement a set of universal quantum gates, allowing the system to be used as a
universal quantum computer.


title: Exciton condensation due to electron-phonon interaction

abstract:
  We show that the coupling to vibrational degrees of freedom can drive a
semimetal excitonic-insulator quantum phase transition in an one-dimensional
two-band f-c electron system at zero temperature. The insulating state typifies
an excitonic condensate accompanied by a finite lattice distortion. Using the
projector-based renormalization method we analyze the ground-state and spectral
properties of the interacting electron-phonon model at half-filling. In
particular we calculate the momentum dependence of the excitonic order
parameter function and determine the finite critical interaction strength for
the metal-insulator transition to appear. The electron spectral function
reveals the strong hybridization of f- and c-electron states and the opening of
a single-particle excitation gap. The phonon spectral function indicates that
the phonon mode involved in the transition softens (hardens) in the adiabatic
(non-adiabatic and extreme anti-adiabatic) phonon frequency regime.


title:
A splitting higher order scheme with discrete transparent boundary
  conditions for the Schr\"odinger equation in a semi-infinite parallelepiped

abstract:
  An initial-boundary value problem for the $n$-dimensional ($n\geq 2$)
time-dependent Schr\"odinger equation in a semi-infinite (or infinite)
parallelepiped is considered. Starting from the Numerov-Crank-Nicolson
finite-difference scheme, we first construct higher order scheme with splitting
space averages having much better spectral properties for $n\geq 3$. Next we
apply the Strang-type splitting with respect to the potential and, third,
construct discrete transparent boundary conditions (TBC). For the resulting
method, the uniqueness of solution and the unconditional uniform in time
$L^2$-stability (in particular, $L^2$-conservativeness) are proved. Owing to
the splitting, an effective direct algorithm using FFT (in the coordinate
directions perpendicular to the leading axis of the parallelepiped) is
applicable for general potential. Numerical results on the 2D tunnel effect for
a P\"{o}schl-Teller-like potential-barrier and a rectangular potential-well are
also included.


title: Particle detectors in curved spacetime quantum field theory

abstract:
  Unruh-DeWitt particle detector models are studied in a variety of
time-dependent and time-independent settings. We work within the framework of
first-order perturbation theory and couple the detector to a massless scalar
field. The necessity of switching on (off) the detector smoothly is emphasised
throughout, and the transition rate is found by taking the sharp-switching
limit of the regulator-free and finite response function. The detector is
analysed on a variety of spacetimes: $d$-dimensional Minkowski, the
Ba\~nados-Teitelboim-Zanelli (BTZ) black hole, the two-dimensional Minkowski
half-plane, two-dimensional Minkowski with a receding mirror, and the two- and
four-dimensional Schwarzschild black holes. In $d$-dimensional Minkowski
spacetime, the transition rate is found to be finite up to dimension five. In
dimension six, the transition rate diverges unless the detector is on a
trajectory of constant proper acceleration, and the implications of this
divergence to the global embedding spacetime (GEMS) methods are studied. In
three-dimensional curved spacetime, the transition rate for the scalar field in
an arbitrary Hadamard state is found to be finite and regulator-free. Then on
the Ba\~nados-Teitelboim-Zanelli (BTZ) black hole spacetime, we analyse the
detector coupled to the field in the Hartle-Hawking vacua, under both
transparent and reflective boundary conditions at infinity. Results are
presented for the co-rotating detector, which responds thermally, and for the
radially-infalling detector. In four-dimensional Schwarzschild spacetime, we
proceed numerically, and the Hartle-Hawking, Boulware and Unruh vacua rates are
compared. Results are presented for the case of the static detectors, which
respond thermally, and also for the case of co-rotating detectors.


title:
Low superfluid density and possible multi-gap superconductivity in
  BiS2-based layered superconductor Bi4O4S3

abstract:
  The magnetic penetration depth as a function of temperature in Bi4O4S3 was
studied by muon-spin-spectroscopy measurements. The superfluid density of
Bi4O4S3 is found to be very low. The dependence of penetration depth on
temperature possibly suggests the existence of two s-wave type energy gaps with
the zero-temperature values of 0.93(3) and 0.09(4) meV. The upturn in the
temperature dependence of the upper critical field close to Tc further supports
multi-gap superconductivity in Bi4O4S3. The presence of two superconducting
energy gaps is consistent with theoretical and other experimental studies.
However, a single-gap s-wave model fit with a gap of 0.88(2) meV can not be
ruled out completely. The value of penetration depth at T = 0 K is estimated to
be of 861(17) nm, one of the largest of all known layered superconductors,
reflecting a very low superfluid density.


title: Dynamics of quasiparticle trapping in Andreev levels

abstract:
  We present a theory describing the trapping and untrapping of quasiparticles
in the Andreev bound level of a single-channel weak link between two
superconductors. We calculate the rates of the transitions between even and odd
occupations of the Andreev level induced by absorption and emission of both
photons and phonons. We apply the theory to a recent experiment [Phys. Rev.
Lett. 106, 257003 (2011)] in which the dynamics of the trapping of
quasiparticles in the Andreev levels of superconducting atomic contacts coupled
to a Josephson junction was measured. We show that the plasma energy $h\nu_p$
of the Josephson junction defines a rather abrupt transition between a fast
relaxation regime dominated by coupling to photons and a slow relaxation regime
dominated by coupling to phonons. With realistic parameters the theory provides
a semi-quantitative description of the experimental results.


title:
Exact Ultra Cold Neutrons' Energy Spectrum in Gravitational Quantum
  Mechanics

abstract:
  We find exact energy eigenvalues and eigenfunctions of the quantum bouncer in
the presence of the minimal length uncertainty and the maximal momentum. This
form of Generalized (Gravitational) Uncertainty Principle (GUP) agrees with
various theories of quantum gravity and predicts a minimal length uncertainty
proportional to $\hbar\sqrt{\beta}$ and a maximal momentum proportional to
$1/\sqrt{\beta}$, where $\beta$ is the deformation parameter. We also find the
semiclassical energy spectrum and discuss the effects of this GUP on the
transition rate of the ultra cold neutrons in gravitational spectrometers.
Then, based on the Nesvizhevsky's famous experiment, we obtain an upper bound
on the dimensionless GUP parameter.


title: Flavor Physics and Lattice QCD

abstract:
  Our ability to resolve new physics effects is, largely, limited by the
precision with which we calculate. The calculation of observables in the
Standard (or a new physics) Model requires knowledge of associated hadronic
contributions. The precision of such calculations, and therefore our ability to
leverage experiment, is typically limited by hadronic uncertainties. The only
first-principles method for calculating the nonperturbative, hadronic
contributions is lattice QCD. Modern lattice calculations have controlled
errors, are systematically improvable, and in some cases, are pushing the
sub-percent level of precision. I outline the role played by, highlight state
of the art efforts in, and discuss possible future directions of lattice
calculations in flavor physics.


title: Variable rotational line broadening in the Be star Achernar

abstract:
  The main theoretical problem for the formation of a Keplerian disk around Be
stars is how to supply angular momentum from the star to the disk, even more so
since Be stars probably rotate somewhat sub-critically. For instance, nonradial
pulsation may transport angular momentum to the stellar surface until (part of)
this excess supports the disk formation/replenishment. The nearby Be star
Achernar is presently building a new disk and offers an excellent opportunity
to observe this process from relatively close-up. Spectra from various sources
and epochs are scrutinized to identify the salient stellar parameters
characterizing the disk life cycle as defined by H\alpha emission. Variable
strength of the non-radial pulsation is confirmed, but does not affect the
further results. For the first time it is demonstrated that the photospheric
line width does vary in a Be star, by as much as \Delta v sin i \lesssim
35kms^{-1}. However, contrary to assumptions in which a photospheric spin-up
accumulates during the diskless phase and then is released into the disk as it
is fed, the apparent photospheric spin-up is positively correlated with the
appearance of H\alpha line emission: The photospheric line widths and
circumstellar emission increase together, and the apparent stellar rotation
declines to the value at quiescence after the H\alpha line emission becomes
undetectable.


title:
Finding Linear Dependencies in Integration-By-Parts Equations: A Monte
  Carlo Approach

abstract:
  The reduction of a large number of scalar integrals to a small set of master
integrals via Laporta's algorithm is common practice in multi-loop
calculations. It is also a major bottleneck in terms of running time and memory
consumption. It involves solving a large set of linear equations where many of
the equations are linearly dependent. We propose a simple algorithm that
eliminates all linearly dependent equations from a given system, reducing the
time and space requirements of a subsequent run of Laporta's algorithm.


title: Small Polynomial Time Universal Petri Nets

abstract:
  The time complexity of the presented in 2013 by the author small universal
Petri nets with the pairs of places/transitions numbers (14,42) and (14,29) was
estimated as exponential. In the present paper, it is shown, that their slight
modification and interpretation as timed Petri nets with multichannel
transitions, introduced by the author in 1991, allows obtaining polynomial time
complexity. The modification concerns using only inhibitor arcs to control
transitions' firing in multiple instances and employing an inverse control flow
represented by moving zero. Thus, small universal Petri nets are efficient that
justifies their application as models of high performance computations.


title:
A General Stochastic Information Diffusion Model in Social Networks
  based on Epidemic Diseases

abstract:
  Social networks are an important infrastructure for information, viruses and
innovations propagation. Since users behavior has influenced by other users
activity, some groups of people would be made regard to similarity of users
interests. On the other hand, dealing with many events in real worlds, can be
justified in social networks; spreading disease is one instance of them. People
manner and infection severity are more important parameters in dissemination of
diseases. Both of these reasons derive, whether the diffusion leads to an
epidemic or not. SIRS is a hybrid model of SIR and SIS disease models to spread
contamination. A person in this model can be returned to susceptible state
after it removed. According to communities which are established on the social
network, we use the compartmental type of SIRS model. During this paper, a
general compartmental information diffusion model would be proposed and
extracted some of the beneficial parameters to analyze our model. To adapt our
model to realistic behaviors, we use Markovian model, which would be helpful to
create a stochastic manner of the proposed model. In the case of random model,
we can calculate probabilities of transaction between states and predicting
value of each state. The comparison between two mode of the model shows that,
the prediction of population would be verified in each state.


title: Property A and uniform embedding for locally compact groups

abstract:
  For locally compact groups, we define an analogue to Yu's property A that he
defined for discrete metric spaces. We show that our property A for locally
compact groups agrees with Roe's notion of property A for proper metric spaces,
defined in \cite{R05}. We prove that many of the results that are known to hold
in the discrete setting, hold also in the locally compact setting. In
particular, we show that property A is equivalent to amenability at infinity
(see \cite{HR00} for the discrete case), and that a locally compact group with
property A embeds uniformly into a Hilbert space (see \cite{Yu00} for the
discrete case). We also prove that the Baum-Connes assembly map with
coefficients is split-injective, for every locally compact group that embeds
uniformly into a Hilbert space. This extends results by Skandalis, Tu and Yu
\cite{STY02}, and by Chabert, Echterhoff and Oyono-Oyono \cite{CEO04}.


title:
Large time behavior for a porous medium equation in a nonhomogeneous
  medium with critical density

abstract:
  We study the large time behavior of solutions to the porous medium equation
in nonhomogeneous media with critical singular density $$
|x|^{-2}\partial_{t}u=\Delta u^m, \quad \hbox{in} \ \real^N\times(0,\infty), $$
where $m>1$ and $N\geq3$. The asymptotic behavior proves to have some
interesting and striking properties. We show that there are different
asymptotic profiles for the solutions, depending on whether the continuous
initial data $u_0$ vanishes at $x=0$ or not. Moreover, when $u_0(0)=0$, we show
the convergence towards a profile presenting a discontinuity in form of a
shockwave, coming from an unexpected asymptotic simplification to a
conservation law, while when $u_0(0)>0$, the limit profile remains continuous.
These phenomena illustrate the strong effect of the singularity at $x=0$. We
improve the time scale of the convergence in sets avoiding the singularity. On
the way, we also study the large-time behavior for a porous medium equation
with convection which is interesting for itself.


title: Mapping continuous potentials to discrete forms

abstract:
  The optimal conversion of a continuous inter-particle potential to a discrete
equivalent is considered here. Existing and novel algorithms are evaluated to
determine the best technique for creating accurate discrete forms using the
minimum number of discontinuities. This allows the event-driven molecular
dynamics technique to be efficiently applied to the wide range of continuous
force models available in the literature, and facilitates a direct comparison
of event-driven and time-driven molecular dynamics. The performance of the
proposed conversion techniques are evaluated through application to the
Lennard-Jones model. A surprising linear dependence of the computational cost
on the number of discontinuities is found, allowing accuracy to be traded for
speed in a controlled manner. Excellent agreement is found for static and
dynamic properties using a relatively low number of discontinuities. For the
Lennard-Jones potential, the optimized discrete form outperforms the original
continuous form at gas densities but is significantly slower at higher
densities.


title: WW production at high transverse momenta beyond NLO

abstract:
  Pair production of W gauge bosons is an important process at the LHC entering
many experimental analyses, both as background in new-physics searches or Higgs
measurements and as signal in precision studies and tests of the Standard
Model. Therefore, accurate predictions for this class of processes are of great
interest in order to exploit the full potential of LHC measurements. We use the
LoopSim method to combine NLO QCD results for WW and WW+jet, as well as the
loop-squared gluon-fusion contribution, to obtain approximate NNLO predictions
for WW production. The cross sections are calculated with VBFNLO and include
leptonic decays of the W bosons as well as finite-width and off-shell effects.
We find that the size of the additional corrections beyond NLO can be
significant and well outside of the NLO error bands given by renormalization
and factorization scale variation. Applying a jet veto, we observe further
negative corrections at NNLO, which we relate to the presence of large Sudakov
logarithms.


title:
High-resolution measurement of the time-modulated orbital electron
  capture and of the $\beta^+$ decay of hydrogen-like $^{142}$Pm$^{60+}$ ions

abstract:
  The periodic time modulations, found recently in the two-body orbital
electron-capture (EC) decay of both, hydrogen-like $^{140}$Pr$^{58+}$ and
$^{142}$Pm$^{60+}$ ions, with periods near to 7s and amplitudes of about 20%,
were re-investigated for the case of $^{142}$Pm$^{60+}$ by using a 245 MHz
resonator cavity with a much improved sensitivity and time resolution. We
observed that the exponential EC decay is modulated with a period $T =
7.11(11)$s, in accordance with a modulation period $T = 7.12(11)$ s as obtained
from simultaneous observations with a capacitive pick-up, employed also in the
previous experiments. The modulation amplitudes amount to $a_R = 0.107(24)$ and
$a_P = 0.134(27)$ for the 245 MHz resonator and the capacitive pick-up,
respectively. These new results corroborate for both detectors {\it exactly}
our previous findings of modulation periods near to 7s, though with {\it
distinctly smaller} amplitudes. Also the three-body $\beta^+$ decays have been
analyzed. For a supposed modulation period near to 7s we found an amplitude $a
= 0.027(27)$, compatible with $a = 0$ and in agreement with the preliminary
result $a = 0.030(30)$ of our previous experiment. These observations could
point at weak interaction as origin of the observed 7s-modulation of the EC
decay. Furthermore, the data suggest that interference terms occur in the
two-body EC decay, although the neutrinos are not directly observed.


title: Linear extensions of orders invariant under abelian group actions

abstract:
  Let G be an abelian group acting on a set X, and suppose that no element of G
has any finite orbit of size greater than one. We show that every partial order
on X invariant under $G$ extends to a linear order on X also invariant under G.
We then discuss extensions to linear preorders when the orbit condition is not
met, and show that for any abelian group acting on a set X, there is a linear
preorder <= on the powerset PX invariant under G and such that if A is a proper
subset of B, then A<B (i.e., A<=B but not B<=A).


title: Astrophysical constraints on Planck scale dissipative phenomena

abstract:
  The emergence of a classical spacetime from any quantum gravity model is
still a subtle and only partially understood issue. If indeed spacetime is
arising as some sort of large scale condensate of more fundamental objects then
it is natural to expect that matter, being a collective excitations of the
spacetime constituents, will present modified kinematics at sufficiently high
energies. We consider here the phenomenology of the dissipative effects
necessarily arising in such a picture. Adopting dissipative hydrodynamics as a
general framework for the description of the energy exchange between collective
excitations and the spacetime fundamental degrees of freedom, we discuss how
rates of energy loss for elementary particles can be derived from dispersion
relations and used to provide strong constraints on the base of current
astrophysical observations of high energy particles.


title: On the Standard Model Group in F-theory

abstract:
  We analyze the Standard Model gauge group SU(3) x SU(2) x U(1) constructed in
F-theory. The non-Abelian part SU(3) x SU(2) is described by singularities of
Kodaira type. It is distinguished to naive product of SU(3) and SU(2), revealed
by blow-up analysis, since the resolution procedures cannot be done separately
to each group. The Abelian part U(1) is constructed by obtaining a desirable
global two-form harboring it, using `factorization method' similar to the
decomposition method of the spectral cover; It makes use of an extra section in
the elliptic fiber of the Calabi-Yau manifold, on which F-theory is
compactified. Conventional gauge coupling unification of SU(5) is achieved,
without threshold correction from the flux along hypercharge direction.


title: A Greedy Algorithm for the Analysis Transform Domain

abstract:
  Many image processing applications benefited remarkably from the theory of
sparsity. One model of sparsity is the cosparse analysis one. It was shown that
using l_1-minimization one might stably recover a cosparse signal from a small
set of random linear measurements if the operator is a frame. Another effort
has provided guarantees for dictionaries that have a near optimal projection
procedure using greedy-like algorithms. However, no claims have been given for
frames. A common drawback of all these existing techniques is their high
computational cost for large dimensional problems.
  In this work we propose a new greedy-like technique with theoretical recovery
guarantees for frames as the analysis operator, closing the gap between greedy
and relaxation techniques. Our results cover both the case of bounded
adversarial noise, where we show that the algorithm provides us with a stable
reconstruction, and the one of random Gaussian noise, for which we prove that
it has a denoising effect, closing another gap in the analysis framework. Our
proposed program, unlike the previous greedy-like ones that solely act in the
signal domain, operates mainly in the analysis operator's transform domain.
Besides the theoretical benefit, the main advantage of this strategy is its
computational efficiency that makes it easily applicable to visually big data.
We demonstrate its performance on several high dimensional images.


title: Ternary superderivations of Jordan superalgebras

abstract:
  We describe the ternary and the generalized superderivations of
finite-dimensional semisimple Jordan superalgebras over an algebraically closed
field of characteristic zero and of finite-dimensional simple Jordan
superalgebras with semisimple even part over an algebraically closed field of
any characteristic not equal 2.


title:
Search for technipions in exclusive production of diphotons with large
  invariant masses at the LHC

abstract:
  We focus on exclusive production of neutral technipion $\tilde \pi^0$ in $pp$
collisions at the LHC, i.e. on $p p \to p p \tilde \pi^0$ reaction. The
dependence of the cross section on parameters of recently proposed vector-like
Technicolor model is studied. Characteristic features of the differential
distributions are discussed. For not too large technipion masses the diphoton
decay channel has the dominant branching fraction. This is also the main reason
for an enhanced production of neutral technipions in $\gamma\gamma$-fusion
reaction. We discuss potential backgrounds of the QCD and QED origin to the $p
p \to p p (\tilde{\pi}^0 \to \gamma \gamma)$ process at large invariant
$\gamma\gamma$ masses. We conclude that compared to inclusive case the
signal-to-background ratio in the considered exclusive reaction is vary
favorable which thereby could serve as a good probe for Technicolor dynamics
searches at the LHC.


title: A categorification of Grassmannian cluster algebras

abstract:
  We describe a ring whose category of Cohen-Macaulay modules provides an
additive categorification of the cluster algebra structure on the homogeneous
coordinate ring of the Grassmannian of k-planes in n-space. More precisely,
there is a cluster character defined on the category which maps the rigid
indecomposable objects to the cluster variables and the maximal rigid objects
to clusters. This is proved by showing that the quotient of this category by a
single projective-injective object is Geiss-Leclerc-Schroer's category Sub
$Q_k$, which categorifies the coordinate ring of the big cell in this
Grassmannian.


title: Critical Casimir Forces for Films with Bulk Ordering Fields

abstract:
  The confinement of long-ranged critical fluctuations in the vicinity of
second-order phase transitions in fluids generates critical Casimir forces
acting on confining surfaces or among particles immersed in a critical solvent.
This is realized in binary liquid mixtures close to their consolute point
$T_{c}$ which belong to the universality class of the Ising model. The
deviation of the difference of the chemical potentials of the two species of
the mixture from its value at criticality corresponds to the bulk magnetic
filed of the Ising model. By using Monte Carlo simulations for this latter
representative of the corresponding universality class we compute the critical
Casimir force as a function of the bulk ordering field at the critical
temperature $T=T_{c}$. We use a coupling parameter scheme for the computation
of the underlying free energy differences and an energy-magnetization
integration method for computing the bulk free energy density which is a
necessary ingredient. By taking into account finite-size corrections, for
various types of boundary conditions we determine the universal Casimir force
scaling function as a function of the scaling variable associated with the bulk
field. Our numerical data are compared with analytic results obtained from
mean-field theory.


title: Associative and preassociative functions

abstract:
  We investigate the associativity property for functions of indefinite arities
and introduce and discuss the more general property of preassociativity, a
generalization of associativity which does not involve any composition of
functions.


title: Phenomenology of Transverse Momentum Dependent Parton Densities

abstract:
  This talk provides a short overview of the phenomenology of transverse
momentum depedent distribution and fragmention functions, focussing on the most
recent phenomenological developments in the study of their scale evolution and
energy depedence.


title: Charming mesons with baryons and nuclei

abstract:
  The properties of charmed mesons in nuclear matter and nuclei are reviewed.
Different frameworks are discussed paying a special attention to unitarized
coupled-channel approaches which incorporate heavy-quark spin symmetry. Several
charmed baryon states with negative parity are generated dynamically by the
s-wave interaction between pseudoscalar and vector meson multiplets with
$1/2^+$ and $3/2^+$ baryons. These states are compared to experimental data.
Moreover, the properties of open-charm mesons in matter are analyzed. The
in-medium solution accounts for Pauli blocking effects, and for the meson
self-energies in a self-consistent manner. The behavior in the nuclear medium
of the rich spectrum of dynamically-generated baryon states is studied as well
as their influence in the self-energy and, hence, the spectral function of open
charm. The possible experimental signatures of the in-medium properties of open
charm are finally addressed, such as the formation of charmed nuclei, in
connection with the future FAIR facility.


title:
Understanding early indicators of critical transitions in power systems
  from autocorrelation functions

abstract:
  Many dynamical systems, including power systems, recover from perturbations
more slowly as they approach critical transitions---a phenomenon known as
critical slowing down. If the system is stochastically forced, autocorrelation
and variance in time-series data from the system often increase before the
transition, potentially providing an early warning of coming danger. In some
cases, these statistical patterns are sufficiently strong, and occur
sufficiently far from the transition, that they can be used to predict the
distance between the current operating state and the critical point. In other
cases CSD comes too late to be a good indicator. In order to better understand
the extent to which CSD can be used as an indicator of proximity to bifurcation
in power systems, this paper derives autocorrelation functions for three small
power system models, using the stochastic differential algebraic equations
(SDAE) associated with each. The analytical results, along with numerical
results from a larger system, show that, although CSD does occur in power
systems, its signs sometimes appear only when the system is very close to
transition. On the other hand, the variance in voltage magnitudes consistently
shows up as a good early warning of voltage collapse. Finally, analytical
results illustrate the importance of nonlinearity to the occurrence of CSD.


title: Source of entangled atom pairs on demand, using the Rydberg blockade

abstract:
  Two ultracold atom clouds, each separately in a dipole-blockade regime,
realize a source of entangled atom pairs that can be ejected on demand.
Entanglement generation and ejection is due to resonant dipole-dipole
interactions, while van-der-Waals interactions are predominantly responsible
for the blockade that ensures the ejection of a single atom per cloud. A source
of entangled atoms using these effects can operate with a 10 kHz repetition
rate producing ejected atoms with velocities of about 0.5 m/s.


title:
Band filling effect on polaron localization in
  La$_{1-x}($Ca$_y$Sr$_{1-y}$)$_{x}$MnO$_3$ manganites

abstract:
  We report on an a $\mu$SR and $^{55}$Mn NMR investigation of the magnetic
order parameter as a function of temperature in the optimally doped
La$_{5/8}$(Ca$_y$Sr$_{1-y}$)$_{3/8}$MnO$_3$ and in the underdoped
La$_{1-x}$Sr$_{x}$MnO$_3$ and La$_{1-x}$Ca$_{x}$MnO$_3$ metallic manganite
families. The study is aimed at unraveling the effect of lattice distortions,
implicitly controlled by the Ca-Sr isoelectronic substitution, from that of
hole doping $x$ on the Curie temperature $T_c$ and the order of the magnetic
transition. At optimal doping, the transitions are second order at all $y$
values, including the $y=1$ (La$_{5/8}$Ca$_{3/8}$MnO$_3$) end member. In
contrast, they are first order in the underdoped samples, which show a finite
(truncated) order parameter at the Curie point, including
La$_{0.75}$Sr$_{0.25}$MnO$_3$ whose $T_c$ is much higher than that of
La$_{5/8}$Ca$_{3/8}$MnO$_3$. The order parameter curves, on the other hand,
exhibit a very minor dependence on $x$, if truncation is excepted. This
suggests that the effective exchange interaction between Mn ions is essentially
governed by local distortions, in agreement with the original double-exchange
model, while truncation is primarily, if not entirely, an effect of under- or
overdoping. A phase diagram, separating in the $x-y$ plane polaron-driven first
order transitions from regular second order transitions governed by critical
fluctuations, is proposed for the La$_{1-x}($Ca$_y$Sr$_{1-y}$)$_{x}$MnO$_3$
system.


title: Probing the geometry of quantum states with symmetric POVMs

abstract:
  The geometry of the Quantum State Space, described by Bloch vectors, is a
very intricate one. A deeper understanding of this geometry could lead to the
solution of some difficult problems in Quantum Foundations and Quantum
Information such as the existence of SIC-POVMs and the cardinality of the
maximal set of MUBs. In this paper we show that the geometry of quantum states
can be described by the probability distributions that quantum states induce
over the outcomes of symmetric POVMs not necessarily of arbitrary rank or
informationally complete. We also describe the properties of these symmetric
POVMs.


title:
A study of $\eta K \bar K$ and $\eta' K \bar K$ with the fixed center
  approximation to Faddeev equations

abstract:
  In the present work we investigate the three-body systems of $\eta K \bar K$
and $\eta' K \bar K$, by taking the fixed center approximation to Faddeev
equations. We find a clear and stable resonance structure around 1490 MeV in
the squared $\eta K \bar K$ scattering amplitude, which is not sensitive to the
renormalization parameters. Conversely, we get only an enhancement effect of
the threshold in the $\eta' K \bar K$ amplitude that indicates the difficulty
to bind the $\eta' K \bar K$ system as a consequence of a weaker $\eta' K$
interaction than the $\eta K$ one. We associate the $\eta K \bar K$ state found
to the $\eta(1475)$.


title: Bayesian Inference in Sparse Gaussian Graphical Models

abstract:
  One of the fundamental tasks of science is to find explainable relationships
between observed phenomena. One approach to this task that has received
attention in recent years is based on probabilistic graphical modelling with
sparsity constraints on model structures. In this paper, we describe two new
approaches to Bayesian inference of sparse structures of Gaussian graphical
models (GGMs). One is based on a simple modification of the cutting-edge block
Gibbs sampler for sparse GGMs, which results in significant computational gains
in high dimensions. The other method is based on a specific construction of the
Hamiltonian Monte Carlo sampler, which results in further significant
improvements. We compare our fully Bayesian approaches with the popular
regularisation-based graphical LASSO, and demonstrate significant advantages of
the Bayesian treatment under the same computing costs. We apply the methods to
a broad range of simulated data sets, and a real-life financial data set.


title: Development and Transcription of Assamese Speech Corpus

abstract:
  A balanced speech corpus is the basic need for any speech processing task. In
this report we describe our effort on development of Assamese speech corpus. We
mainly focused on some issues and challenges faced during development of the
corpus. Being a less computationally aware language, this is the first effort
to develop speech corpus for Assamese. As corpus development is an ongoing
process, in this paper we report only the initial task.


title: Timeline Generation: Tracking individuals on Twitter

abstract:
  In this paper, we propose a unsupervised framework to reconstruct a person's
life history by creating a chronological list for {\it personal important
events} (PIE) of individuals based on the tweets they published. By analyzing
individual tweet collections, we find that what are suitable for inclusion in
the personal timeline should be tweets talking about personal (as opposed to
public) and time-specific (as opposed to time-general) topics. To further
extract these types of topics, we introduce a non-parametric multi-level
Dirichlet Process model to recognize four types of tweets: personal
time-specific (PersonTS), personal time-general (PersonTG), public
time-specific (PublicTS) and public time-general (PublicTG) topics, which, in
turn, are used for further personal event extraction and timeline generation.
To the best of our knowledge, this is the first work focused on the generation
of timeline for individuals from twitter data. For evaluation, we have built a
new golden standard Timelines based on Twitter and Wikipedia that contain PIE
related events from 20 {\it ordinary twitter users} and 20 {\it celebrities}.
Experiments on real Twitter data quantitatively demonstrate the effectiveness
of our approach.


title: Majorana fermions coupled to electromagnetic radiation

abstract:
  We consider a voltage-biased Josephson junction between two nanowires hosting
Majorana zero modes which occur as topological protected zero-energy
excitations at the junction. We show that two Majorana fermions localized at
the junction, even though being neutral particles, interact with the
electromagnetic field and generate coherent radiation similar to the
conventional Josephson radiation. Within a semiclassical analysis of the
radiation field, we find that the optical phase gets locked to the
superconducting phase difference and that the radiation is emitted at half the
Josephson frequency. In order to confirm the coherence of the radiation, we
study correlations of the radiation emitted by two spatially-separated
junctions in a d.c.-SQUID geometry taking into account decoherence due to
spontaneous state-switches as well as due to quasi-particle poisoning.


title: Nonlinear Compressive Particle Filtering

abstract:
  Many systems for which compressive sensing is used today are dynamical. The
common approach is to neglect the dynamics and see the problem as a sequence of
independent problems. This approach has two disadvantages. Firstly, the
temporal dependency in the state could be used to improve the accuracy of the
state estimates. Secondly, having an estimate for the state and its support
could be used to reduce the computational load of the subsequent step. In the
linear Gaussian setting, compressive sensing was recently combined with the
Kalman filter to mitigate above disadvantages. In the nonlinear dynamical case,
compressive sensing can not be used and, if the state dimension is high, the
particle filter would perform poorly. In this paper we combine one of the most
novel developments in compressive sensing, nonlinear compressive sensing, with
the particle filter. We show that the marriage of the two is essential and that
neither the particle filter or nonlinear compressive sensing alone gives a
satisfying solution.


title: Free field realizations of the Date-Jimbo-Kashiwara-Miwa algebra

abstract:
  We use the description of the universal central extension of the DJKM algebra
$\mathfrak{sl}(2, R)$ where $ R=\mathbb C[t,t^{-1},u\,|\,u^2=t^4-2ct^2+1 ]$
given in earlier work to construct realizations of the DJKM algebra in terms of
sums of partial differential operators.


title:
An empirical Bayesian analysis applied to the globular cluster pulsar
  population

abstract:
  We describe an empirical Bayesian approach to determine the most likely size
of an astronomical population of sources of which only a small subset are
observed above some limiting flux density threshold. The method is most
naturally applied to astronomical source populations at a common distance
(e.g.,stellar populations in globular clusters), and can be applied even to
populations where a survey detects no objects. The model allows for the
inclusion of physical parameters of the stellar population and the detection
process. As an example, we apply this method to the current sample of radio
pulsars in Galactic globular clusters. Using the sample of flux density limits
on pulsar surveys in 94 globular clusters published by Boyles et al., we
examine a large number of population models with different dependencies. We
find that models which include the globular cluster two-body encounter rate,
$\Gamma$, are strongly favoured over models in which this is not a factor. The
optimal model is one in which the mean number of pulsars is proportional to
$\exp(1.5 \log \Gamma)$. This model agrees well with earlier work by Hui et al.
and provides strong support to the idea that the two-body encounter rate
directly impacts the number of neutron stars in a cluster. Our model predicts
that the total number of potentially observable globular cluster pulsars in the
Boyles et al. sample is 1070$^{+1280}_{-700}$, where the uncertainties signify
the 95% confidence interval. Scaling this result to all Galactic globular
clusters, and to account for radio pulsar beaming, we estimate the total
population to be 2280$^{+2720}_{-1490}$.


title: Signatures of nonadiabatic BCS state dynamics in pump-probe conductivity

abstract:
  We theoretically study the pump-probe response of nonequilibrium BCS
superconductors coupled to optical phonons. For ultrashort pump pulses a
nonadiabatic regime emerges, which is characterized by oscillations of the
superconducting order parameter as well as by the generation of coherent
phonons. Using the density-matrix formalism, we compute the pump-probe response
in the nonadiabatic regime of the coupled Bogoliubov quasiparticle-phonon
system and determine the signatures of the order parameter and of the phonon
oscillations in the pump-probe conductivity. We find that the nonadiabatic
dynamics of the BCS superconductor reflects itself in oscillations of the
pump-probe response as functions of delay time between pump and probe pulses.
We argue that from the analysis of this oscillatory behavior both frequency and
decay time of the algebraically decaying order-parameter oscillations can be
inferred. Similarly, the coherent phonons are evidenced in the pump-probe
conductivity by oscillations with the frequency of the phonons. Remarkably, we
find that the oscillatory response in the pump-probe conductivity is resonantly
enhanced when the frequency of the order-parameter oscillations is tuned to the
phonon energy.


title: Tropical bounds for eigenvalues of matrices

abstract:
  We show that for all k = 1,...,n the absolute value of the product of the k
largest eigenvalues of an n-by-n matrix A is bounded from above by the product
of the k largest tropical eigenvalues of the matrix |A| (entrywise absolute
value), up to a combinatorial constant depending only on k and on the pattern
of the matrix. This generalizes an inequality by Friedland (1986),
corresponding to the special case k = 1.


title:
On Protecting the Planet Against Cosmic Attack: Ultrafast Real-Time
  Estimate of the Asteroid's Radial Velocity

abstract:
  A new method for the line-of-sight velocity estimation of a high-speed
near-Earth object (asteroid, meteorite) is suggested. The method is based on
use of fractional, one-half order derivative of a Doppler signal. The algorithm
suggested is much simpler and more economical than the classical one, and it
appears preferable for use in orbital weapon systems of threat response.
Application of fractional differentiation to quick evaluation of mean frequency
location of the reflected Doppler signal is justified. The method allows an
assessment of the mean frequency in the time domain without spectral analysis.
An algorithm structure for the real-time estimation is presented. The velocity
resolution estimates are made for typical asteroids in the X-band. It is shown
that the wait time can be shortened by orders of magnitude compared with
similar value in the case of a standard spectral processing.


title:
Recycled Error Bits: Energy-Efficient Architectural Support for Higher
  Precision Floating Point

abstract:
  In this work, we provide energy-efficient architectural support for floating
point accuracy. Our goal is to provide accuracy that is far greater than that
provided by the processor's hardware floating point unit (FPU). Specifically,
for each floating point addition performed, we "recycle" that operation's
error: the difference between the finite-precision result produced by the
hardware and the result that would have been produced by an infinite-precision
FPU. We make this error architecturally visible such that it can be used, if
desired, by software. Experimental results on physical hardware show that
software that exploits architecturally recycled error bits can achieve accuracy
comparable to a 2B-bit FPU with performance and energy that are comparable to a
B-bit FPU.


title:
Combined effect of strain and defects on the conductance of graphene
  nanoribbons

abstract:
  We investigate the combined influence of structural defects and uniaxial
longitudinal strain on the electronic transport properties of armchair graphene
nanoribbons using the numerical approach based on the semiempirical
tight-binding model, the Landauer formalism, and the recursion method for Green
functions. We calculate the conductance of graphene nanoribbons in the quantum
coherent regime with different types and concentrations of defects. Further, we
apply uniform planar tension to the nonideal graphene ribbons with randomly
distributed and oriented single and double vacancies and Stone-Wales defects.
Since transport characteristics of graphene nanoribbons are found to be very
sensitive to edge termination and aspect ratio, and it has been shown that
energy gaps can emerge under critical strain; the interplay of both effects
needs to be studied. We show that band gap engineering using strain is still
possible for nonideal armchair ribbons with a small defect concentration, as
the oscillatory behavior of the gap is preserved.


title:
Inelastic neutron scattering study of crystal field excitations of Nd3+
  in NdFeAsO

abstract:
  Inelastic neutron scattering experiments were performed to investigate the
crystalline electric field (CEF) excitations of Nd3+ (J = 9/2) in the iron
pnictide NdFeAsO. The crystal field level structures for both the
high-temperature paramagnetic phase and the low-temperature antiferromagnetic
phase of NdFeAsO are constructed. The variation of CEF excitations of Nd3+
reflects not only the change of local symmetry but also the change of magnetic
ordered state of the Fe sublattice. By analyzing the crystal field interaction
with a crystal field Hamiltonian, the crystal field parameters are obtained. It
was found that the sign of the fourth and sixth-order crystal field parameters
change upon the magnetic phase transition at 140 K, which may be due to the
variation of exchange interactions between the 4f and conduction electrons.


title:
Solar Dynamics Observatory and Hinode observations of a blowout jet in a
  coronal hole

abstract:
  A blowout jet occurred within the south coronal hole on 9 February 2011 at
09:00 UT and was observed by the Atmospheric Imaging Assembly (AIA) and
Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory,
and the EUV Imaging Spectrometer (EIS) and X-Ray Telescope (XRT) onboard the
Hinode spacecraft during coronal hole monitoring performed as part of Hinode
Operations Program No. 177. Images from AIA show expanding hot and cold loops
from a small bright point with plasma ejected in a curtain up to 30 Mm wide.
The initial intensity front of the jet had a projected velocity of 200 km/s and
line-of-sight (LOS) velocities measured by EIS are between 100 and 250 km/s.
The LOS velocities increased along the jet, implying an acceleration mechanism
operating within the body of the jet. The jet plasma had a density of 2.7 x
10^8 cm^-3, and a temperature of 1.4 MK. During the event a number of bright
kernels were seen at the base of the bright point. The kernels have sizes of
about 1000 km, are variable in brightness, and have lifetimes of 1-15 minutes.
An XRT filter ratio yields temperatures of 1.5-3.0 MK for the kernels. The
bright point existed for at least ten hours, but disappeared within two hours
after the jet, which lasted for 30 minutes. HMI data reveal converging
photospheric flows at the location of the bright point, and the mixed polarity
magnetic flux canceled over a period of four hours on either side of the jet.


title: A rational construction of Lie algebras of type E_7

abstract:
  We give an explicit construction of Lie algebras of type $E_7$ out of a Lie
algebra of type $D_6$ with some restrictions. Up to odd degree extensions,
every Lie algebra of type $E_7$ arises this way. For Lie algebras that admit a
$56$-dimensional representation we provide a more symmetric construction based
on an observation of Manivel; the input is seven quaternion algebras subject to
some relations.


title:
Path-Integral Ground-State and Superfluid Hydrodynamics of a Bosonic Gas
  of Hard Spheres

abstract:
  We study a bosonic gas of hard spheres by using of the exact zero-temperature
Path-Integral Ground-State (PIGS) Monte Carlo method and the equations of
superfluid hydrodynamics. The PIGS method is implemented to calculate for the
bulk system the energy per particle and the condensate fraction through a large
range of the gas parameter $na^3$ (with $n$ the number density and $a$ the
s--wave scattering length), going from the dilute gas into the solid phase. The
Maxwell construction is then adopted to determine the freezing at
$na^3=0.278\pm 0.001$ and the melting at $na^3=0.286\pm 0.001$. In the liquid
phase, where the condensate fraction is finite, the equations of superfluid
hydrodynamics, based on the PIGS equation of state, are used to find other
relevant quantities as a function of the gas parameter: the chemical potential,
the pressure and the sound velocity. In addition, within the Feynman's
approximation, from the PIGS static structure factor we determine the full
excitation spectrum, which displays a maxon-roton behavior when the gas
parameter is close to the freezing value. Finally, the equations of superfluid
hydrodynamics with the PIGS equation of state are solved for bosonic system
under axially--symmetric harmonic confinement obtaining its collective
breathing modes.


title:
High-Order Algorithms for Compressible Reacting Flow with Complex
  Chemistry

abstract:
  In this paper we describe a numerical algorithm for integrating the
multicomponent, reacting, compressible Navier-Stokes equations, targeted for
direct numerical simulation of combustion phenomena. The algorithm addresses
two shortcomings of previous methods. First, it incorporates an eighth-order
narrow stencil approximation of diffusive terms that reduces the communication
compared to existing methods and removes the need to use a filtering algorithm
to remove Nyquist frequency oscillations that are not damped with traditional
approaches. The methodology also incorporates a multirate temporal integration
strategy that provides an efficient mechanism for treating chemical mechanisms
that are stiff relative to fluid dynamical time scales. The overall methodology
is eighth order in space with option for fourth order to eighth order in time.
The implementation uses a hybrid programming model designed for effective
utilization of many-core architectures. We present numerical results
demonstrating the convergence properties of the algorithm with realistic
chemical kinetics and illustrating its performance characteristics. We also
present a validation example showing that the algorithm matches detailed
results obtained with an established low Mach number solver.


title:
Anisotropic plasmon-coupling dimerization of a pair of spherical
  electron gases

abstract:
  We have discovered a novel feature in the plasmon excitations for a pair of
Coulomb-coupled non- concentric spherical two-dimensional electron gases
(S2DEGs). Our results show that the plasmon excitations for such pairs depend
on the orientation with respect to the external electromagnetic probe field.
The origin of this anisotropy of the inter-sphere Coulomb interaction is due to
the directional asymmetry of the electrostatic coupling of electrons in excited
states which depend on both the angular momentum quantum number L and its
projection M on the axis of quantization taken as the probe E-field direction.
We demonstrate the anisotropic inter-sphere Coulomb coupling in space and
present semi-analytic results in the random-phase approximation both
perpendicular and parallel to the axis of quantization. For the incidence of
light with a finite orbital or spin angular momentum, the magnetic field
generated from an induced oscillating electric dipole on one sphere can couple
to an induced magnetic dipole on another sphere in a way depending on the
direction parallel or perpendicular to the probe E field. Such an effect from
the plasmon spatial correlation is expected to be experimentally observable by
employing circularly-polarized light or a helical light beam for incidence. The
S2DEG serves as a simple model for fullerenes as well as metallic dimers, when
the energy bands are far apart.


title: The physical mechanisms that initiate and drive solar eruptions

abstract:
  Solar eruptions are due to a sudden destabilization of force-free coronal
magnetic fields. But the detailed mechanisms which can bring the corona towards
an eruptive stage, then trigger and drive the eruption, and finally make it
explosive, are not fully understood. A large variety of storage-and-release
models have been developed and opposed to each other since 40 years. For
example, photospheric flux emergence vs. flux cancellation, localized coronal
reconnection vs. large-scale ideal instabilities and loss of equilibria,
tether-cutting vs. breakout reconnection, and so on. The competition between
all these approaches has led to a tremendous drive in developing and testing
all these concepts, by coupling state-of-the-art models and observations.
Thanks to these developments, it now becomes possible to compare all these
models with one another, and to revisit their interpretation in light of their
common and their different behaviors. This approach leads me to argue that no
more than two distinct physical mechanisms can actually initiate and drive
prominence eruptions: the magnetic breakout and the torus instability. In this
view, all other processes (including flux emergence, flux cancellation, flare
reconnection and long-range couplings) should be considered as various ways
that lead to, or that strengthen, one of the aforementioned driving mechanisms.


title:
Relativistic Hard-Scattering and Tsallis Fits to pT Spectra in pp
  Collisions at the LHC

abstract:
  Motivated by the good Tsallis fits to the high-pT spectra in pp collisions at
the LHC, we study the relativistic hard-scattering model and obtain an
approximate analytical expression for the differential hard-scattering cross
section at \eta ~ 0. The power-law behaviour of the transverse spectra, in the
form of d\sigma/dpT^2 \propto 1/pT^n, gives a power index n in the range of
4.5-5.5 for jet production as predicted by pQCD, after the dependencies of the
structure functions and the running coupling constant are properly taken into
account. The power indices for hadron production n are slightly greater than
those for jet production.


title: Structural and magnetic properties of Cr-diluted CoFeB

abstract:
  The crystallization process and the magnetization of Cr diluted CoFeB was
investigated in both ribbon samples and thin film samples with Cr content up to
30 at. %. A primary crystallization of bcc phase from an amorphous precursor in
ribbon samples was observed when the annealing temperature rose to between 421
oC and 456 oC, followed by boron segregation at temperatures between 518 oC and
573 oC. The two onset crystallization temperatures showed strong dependences on
both Cr and B concentrations. The impact of Cr concentration on the magnetic
properties including a reduced saturation magnetization and an enhanced
coercive field was also observed. The magnetizations of both ribbon samples and
thin film samples were well fitted using the generalized Slater-Pauling curve
with modified moments for B (-0.94 {\mu}B) and Cr (-3.6 {\mu}B). Possible
origins of the enhanced coercive field were also discussed. We also achieved a
damping parameter in CoFeCrB thin films at the same level as Co40Fe40B20, much
lower than the value reported for CoFeCrB films previously. The results suggest
a possible advantage of CoFeCrB in reducing the critical switching current
density in Spin Transfer Torque Random Access Memory (STT-RAM).


title: The dark aftermath of Higgs inflation

abstract:
  In this letter we study the dynamics of the late Universe when a nonminimally
coupled Higgs field is present. In general, the nonminimal coupling leads to a
nontrivial mixing between the gravitational degrees of freedom and the
Goldstone massless bosons. We know that this is irrelevant during the
inflationary phase. In contrast, in the late Universe the nonminimal coupling
affects the classical equations of motion, leading to an acceleration of the
expansion rate or to a collapse that forms Q-balls.


title: Random normal matrices, Bergman kernel and projective embeddings

abstract:
  We investigate the analogy between the large N expansion in normal matrix
models and the asymptotic expansion of the determinant of the Hilb map,
appearing in the study of critical metrics on complex manifolds via projective
embeddings. This analogy helps to understand the geometric meaning of the
expansion of matrix model free energy and its relation to gravitational
effective actions in two dimensions. We compute the leading terms of the free
energy expansion in the pure bulk case, and make some observations on the
structure of the expansion to all orders. As an application of these results,
we propose an asymptotic formula for the Liouville action, restricted to the
space of the Bergman metrics.


title: Orthogonal Frequency Division Multiplexing and its Applications

abstract:
  Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier
modulation technique which is very much popular in new wireless networks of
IEEE standard, digital television, audio broadcasting and 4G mobile
communications. The main benefit of OFDM over single-carrier schemes is its
ability to cope with severe channel conditions without complex equalization
filters. It has improved the quality of long-distance communication by
eliminating InterSymbol Interference (ISI) and improving Signal-to-Noise ratio
(SNR). The main drawbacks of OFDM are its high peak to average power ratio and
its sensitivity to phase noise and frequency offset. This paper gives an
overview of OFDM, its applications in various systems such as IEEE 802.11a,
Digital Audio Broadcasting (DAB) and Digital Broadcast Services to Handheld
Devices (DVB-H) along with its advantages and disadvantages.


title: The quadratic divergence in the Higgs mass revisited

abstract: Old and new calculations of the Higgs mass quadratic divergence are compared.


title: On first attempts to reconcile quantum principles with gravity

abstract:
  In his 1916's first paper on gravitational waves Einstein began to speculate
on interactions between the principles of the old quantum theory and his theory
of gravitation. With this contribution Einstein has stimulated a lot of similar
speculations, during the dawn and the development of Quantum Mechanics. These
speculations have culminated with the first attempt to quantize the
gravitational field, that was provided by Rosenfeld in 1930. In this paper we
briefly explain why this period (1916-1930) should be inserted into the history
of Quantum Gravity and then we focus on Klein's approach to the problem of
reconciling Wave Mechanics with gravity, during the two-years period 1926-1927.
His attempt should be looked as the prehistory of Quantum Field Theory in a
curved background.


title:
Quarkonium production in high energy proton-nucleus collisions: CGC
  meets NRQCD

abstract:
  We study the production of heavy quarkonium states in high energy
proton-nucleus collisions. Following earlier work of Blaizot, Fujii, Gelis, and
Venugopalan, we systematically include both small $x$ evolution and multiple
scattering effects on heavy quark pair production within the Color Glass
Condensate (CGC) framework. We obtain for the first time expressions in the
Non-Relativistic QCD (NRQCD) factorization formalism for heavy quarkonium
differential cross sections as a function of transverse momentum and rapidity.
We observe that the production of color singlet heavy quark pairs is sensitive
to both "quadrupole" and "dipole" Wilson line correlators, whose energy
evolution is described by the Balitsky-JIMWLK equations. In contrast, the color
octet channel is sensitive to dipole correlators alone. In a quasi-classical
approximation, our results for the color singlet channel reduce to those of
Dominguez et. al. [1]. We compare our results to those obtained combining the
CGC with the color evaporation model and point to qualitative differences in
the two approaches.


title: Opportunities in Neutrino Theory -- a Snowmass White Paper

abstract:
  Neutrino masses are clear evidence for physics beyond the standard model and
much more remains to be understood about the neutrino sector. We highlight some
of the outstanding questions and research opportunities in neutrino theory. We
show that most of these questions are directly connected to the very rich
experimental program currently being pursued (or at least under serious
consideration) in the United States and worldwide. Finally, we also comment on
the state of the theoretical neutrino physics community in the U.S.


title: Quantum Phase Transition of Light in the Rabi-Hubbard Model

abstract:
  We discuss the physics of the Rabi-Hubbard model describing large arrays of
coupled cavities interacting with two level atoms via a Rabi non-linearity. We
show that the inclusion of counter-rotating terms in the light-matter
interaction, often neglected in theoretical descriptions based on
Jaynes-Cumming models, is crucial to stabilize finite-density quantum phases of
correlated photons with no need for an artificially engineered chemical
potential. We show that the physical properties of these phases and the quantum
phase transition occurring between them is remarkably different from those of
interacting bosonic massive quantum particles. The competition between photon
delocalization and Rabi non-linearity drives the system across a novel $Z_2$
parity symmetry-breaking quantum phase transition between two gapped phases, a
Rabi insulator and a delocalized super-radiant phase.


title: Early Stage Influenza Detection from Twitter

abstract:
  Influenza is an acute respiratory illness that occurs virtually every year
and results in substantial disease, death and expense. Detection of Influenza
in its earliest stage would facilitate timely action that could reduce the
spread of the illness. Existing systems such as CDC and EISS which try to
collect diagnosis data, are almost entirely manual, resulting in about two-week
delays for clinical data acquisition. Twitter, a popular microblogging service,
provides us with a perfect source for early-stage flu detection due to its
real- time nature. For example, when a flu breaks out, people that get the flu
may post related tweets which enables the detection of the flu breakout
promptly. In this paper, we investigate the real-time flu detection problem on
Twitter data by proposing Flu Markov Network (Flu-MN): a spatio-temporal
unsupervised Bayesian algorithm based on a 4 phase Markov Network, trying to
identify the flu breakout at the earliest stage. We test our model on real
Twitter datasets from the United States along with baselines in multiple
applications, such as real-time flu breakout detection, future epidemic phase
prediction, or Influenza-like illness (ILI) physician visits. Experimental
results show the robustness and effectiveness of our approach. We build up a
real time flu reporting system based on the proposed approach, and we are
hopeful that it would help government or health organizations in identifying
flu outbreaks and facilitating timely actions to decrease unnecessary
mortality.


title:
OntoMaven: Maven-based Ontology Development and Management of
  Distributed Ontology Repositories

abstract:
  In collaborative agile ontology development projects support for modular
reuse of ontologies from large existing remote repositories, ontology project
life cycle management, and transitive dependency management are important
needs. The Apache Maven approach has proven its success in distributed
collaborative Software Engineering by its widespread adoption. The contribution
of this paper is a new design artifact called OntoMaven. OntoMaven adopts the
Maven-based development methodology and adapts its concepts to knowledge
engineering for Maven-based ontology development and management of ontology
artifacts in distributed ontology repositories.


title:
Electroweakino Searches: A Comparative Study for LHC and ILC (A Snowmass
  White Paper)

abstract:
  We make a systematic and comparative study for the LHC and ILC for the
electroweakino searches in the Minimal Supersymmetric Standard Model. We adopt
a general bottom-up approach and scan over the parameter regions for all the
three cases of the lightest supersymmetric particle being Bino-, Wino-, and
Higgsino-like. The electroweakino signal from pair production and subsequent
decay to Wh (h to b\bar b) final state may yield a sensitivity of 95% C.L.
exclusion (5sigma discovery) to the mass scale M_2, mu ~ 250-400 GeV (200-250
GeV) at the 14 TeV LHC with an luminosity of 300 fb^{-1}. Combining with all
the other decay channels, the 95% C.L. exclusion (5sigma discovery) may be
extended to M_2, mu ~ 480-700 GeV (320-500 GeV). At the ILC, the
electroweakinos could be readily discovered once the kinematical threshold is
crossed, and their properties could be thoroughly studied.


title:
Decay rates of the Higgs boson to two photons and Z plus photon in
  Z_2-symmetric Two Higgs Doublet Models

abstract:
  Analysis of the 125 GeV Higgs boson decay rates to two photons and Z plus
photon in the Inert Doublet Model is presented. We study the constraints on the
masses of the scalars (in particular the Dark Matter candidate) and their
couplings to the Higgs boson, coming from the h -> \gamma\gamma data and
confront them with the WMAP measurements of the Dark Matter relic density.


title: On the dual flow of slow-roll Inflation

abstract:
  We study the dual 3d Euclidean RG flow of single-field slow-roll Inflation
using the postulates of the dS/CFT correspondence. For that purpose we solve
for the inflationary fluctuation at all times using a matching procedure
between two approximate solutions which are separately valid at different
regions of the space of parameters but together cover all of it. The two modes
of the full solution mix such that each of the modes at late times is a
superposition of the modes in the quasi-de Sitter region. We find that the dual
theory admits two phases of explicit and spontaneous breaking of conformal
symmetry.
  We also find that the mixing effect between the two modes in the bulk implies
that slow-roll inflation does not guarantee, but rather generically generates,
a nearly scale invariant power spectrum, except in fine-tuned situations. We
suggest that the mixing effect can have a unique signature on other
cosmological observables such as the bispectrum.


title: Symbiotic Stars in OGLE Data I. Large Magellanic Cloud Systems

abstract:
  Symbiotic stars are long-orbital-period interacting-binaries characterized by
extended emission over the whole electromagnetic range and by complex
photometric and spectroscopic variability. In this paper, the first of a
series, we present OGLE light curves of all the confirmed symbiotic stars in
the Large Magellanic Cloud, with one exception. By careful visual inspection
and combined time-series analysis techniques, we investigate for the first time
in a systematic way the photometric properties of these astrophysical objects,
trying in particular to distinguish the nature of the cool component (e.g.,
Semi-Regular Variable vs. OGLE Small-Amplitude Red Giant), to provide its
first-order pulsational ephemerides, and to link all this information with the
physical parameters of the binary system as a whole. Among the most interesting
results, there is the discovery of a 20-year-long steady fading of Sanduleak's
star, a peculiar symbiotic star known to produce the largest stellar jet ever
discovered. We discuss by means of direct examples the crucial need for
long-term multi-band observations to get a real understanding of symbiotic and
other interacting binary stars. We eventually introduce BOMBOLO, a multi-band
simultaneous imager for the SOAR 4m Telescope, whose design and construction we
are currently leading.


title: Knock-on damage in bilayer graphene: indications for a catalytic pathway

abstract:
  We study by high-resolution transmission electron microscopy the structural
response of bilayer graphene to electron irradiation with energies below the
knock-on damage threshold of graphene. We observe that one type of divacancy,
which we refer to as the butterfly defect, is formed for radiation energies and
doses for which no vacancies are formed in clean monolayer graphene. By using
first principles calculations based on density-functional theory, we analyze
two possible causes related with the presence of a second layer that could
explain the observed phenomenon: an increase of the defect stability or a
catalytic effect during its creation. For the former, the obtained formation
energies of the defect in monolayer and bilayer systems show that the change in
stability is negligible. For the latter, ab initio molecular dynamics
simulations indicate that the threshold energy for direct expulsion does not
decrease in bilayer graphene as compared with monolayer graphene, and we
demonstrate the possibility of creating divacancies through catalyzed
intermediate states below this threshold energy. The estimated cross section
agrees with what is observed experimentally. Therefore, we show the possibility
of a catalytic pathway for creating vacancies under electron radiation below
the expulsion threshold energy.


title: Possible Electric-Field-Induced Superconducting States in Doped Silicene

abstract:
  Silicene has been synthesized recently, with experimental evidence showing
possible superconductivity in the doped case. The noncoplanar low-buckled
structure of this material inspires us to study the pairing symmetry of the
doped system under a perpendicular external electric field. Our study reveals
that the electric field induces an interesting quantum phase transition from
the singlet chiral $d + id'$-wave superconducting phase to the triplet $f$-wave
one. The emergence of the $f$-wave pairing results from the
sublattice-symmetry-breaking caused by the electric field and the
ferromagnetic-like intra-sublattice spin correlations at low dopings. Due to
the enhanced density of states, the superconducting critical temperature of the
system is enhanced by the electric field remarkably. Furthermore, we design a
particular dc SQUID experiment to detect the quantum phase transition predicted
here. Our results, if confirmed, will inject a new vitality to the familiar
Si-based industry through adopting doped silicene as a tunable platform to
study different types of exotic unconventional superconductivities.


title: Freeze-in through portals

abstract:
  The popular freeze-out paradigm for Dark Matter (DM) production, relies on
DM-baryon couplings of the order of the weak interactions. However, different
search strategies for DM have failed to provide a conclusive evidence of such
(non-gravitational) interactions, while greatly reducing the parameter space of
many representative models. This motivates the study of alternative mechanisms
for DM genesis. In the freeze-in framework, the DM is slowly populated from the
thermal bath while never reaching equilibrium. In this work, we analyse in
detail the possibility of producing a frozen-in DM via a mediator particle
which acts as a portal. We give analytical estimates of different freeze-in
regimes and support them with full numerical analyses, taking into account the
proper distribution functions of bath particles. Finally, we constrain the
parameter space of generic models by requiring agreement with DM relic
abundance observations.


title:
Sharpening the Second Law of Thermodynamics with the Quantum Bayes'
  Theorem

abstract:
  We prove a generalization of the classic Groenewold-Lindblad entropy
inequality, combining decoherence and the quantum Bayes theorem into a simple
unified picture where decoherence increases entropy while observation decreases
it. This provides a rigorous quantum-mechanical version of the second law of
thermodynamics, governing how the entropy of a system (the entropy of its
density matrix, partial-traced over the environment and conditioned on what is
known) evolves under general decoherence and observation. The powerful tool of
spectral majorization enables both simple alternative proofs of the classic
Lindblad and Holevo inequalities without using strong subadditivity, and also
novel inequalities for decoherence and observation that hold not only for von
Neumann entropy, but also for arbitrary concave entropies.


title: Deformed supersymmetric gauge theories from the fluxtrap background

abstract:
  The fluxtrap background of string theory provides a transparent and
algorithmic way of constructing supersymmetric gauge theories with both mass
and Omega-type deformations in various dimensions. In this article, we review a
number of deformed supersymmetric gauge theories in two and four dimensions
which can be obtained via the fluxtrap background from string or M-theory. Such
theories, the most well-known being Omega-deformed super Yang-Mills theory in
four dimensions, have met with a lot of interest in the recent literature. The
string theory treatment offers many new avenues of analysis and applications,
such as for example the study of the gravity duals for deformed N=4 gauge
theories.


title: Neutralino Dark Matter with Light Staus

abstract:
  In spite of rapid experimental progress, windows for light superparticles
remain. One possibility is a ~100 GeV tau slepton whose t-channel exchange can
give the correct thermal relic abundance for a relatively light neutralino. We
pedagogically review how this region arises and identify two distinct scenarios
that will be tested soon on multiple fronts. In the first, the neutralino has a
significant down-type higgsino fraction and relatively large rates at direct
detection experiments are expected. In the second, there is large mixing
between two relatively light staus, which could lead to a significant excess in
the Higgs boson branching ratio to photons. In addition, electroweak
superpartners are sufficiently light that direct searches should be effective.


title: Evolution of star clusters in a cosmological tidal field

abstract:
  We present a method to couple N-body star cluster simulations to a
cosmological tidal field, using the Astrophysical Multipurpose Software
Environment. We apply this method to star clusters embedded in the CosmoGrid
dark matter-only LambdaCDM simulation. Our star clusters are born at z = 10
(corresponding to an age of the Universe of about 500 Myr) by selecting a dark
matter particle and initializing a star cluster with 32,000 stars on its
location. We then follow the dynamical evolution of the star cluster within the
cosmological environment.
  We compare the evolution of star clusters in two Milky-Way size haloes with a
different accretion history. The mass loss of the star clusters is continuous
irrespective of the tidal history of the host halo, but major merger events
tend to increase the rate of mass loss. From the selected two dark matter
haloes, the halo that experienced the larger number of mergers tends to drive a
smaller mass loss rate from the embedded star clusters, even though the final
masses of both haloes are similar. We identify two families of star clusters:
native clusters, which become part of the main halo before its final major
merger event, and the immigrant clusters, which are accreted upon or after this
event; native clusters tend to evaporate more quickly than immigrant clusters.
Accounting for the evolution of the dark matter halo causes immigrant star
clusters to retain more mass than when the z=0 tidal field is taken as a static
potential. The reason for this is the weaker tidal field experienced by
immigrant star clusters before merging with the larger dark matter halo.


title:
A tale of two feedbacks: star-formation in the host galaxies of
  radio-AGN

abstract:
  Several lines of argument support the existence of a link between activity at
the nuclei of galaxies, in the form of an accreting supermassive black hole,
and star-formation activity in these galaxies. The exact nature of this link is
still under debate. Radio jets have long been argued to be an ideal mechanism
that allows AGN to interact with their host galaxy and regulate star-formation.
In this context, we are using a sample of radio sources in the North Ecliptic
Pole (NEP) field to study the nature of the putative link between AGN activity
and star-formation. This is done by means of spectral energy distribution (SED)
fitting. We use the excellent spectral coverage of the AKARI infrared space
telescope together with the rich ancillary data available in the NEP to build
SEDs extending from UV to far-IR wavelengths. Through SED fitting we constrain
both the AGN and host galaxy components. We find a significant AGN component in
our sample of relatively faint radio-sources ($<$mJy), that increases in power
with increasing radio-luminosity. At the highest radio-luminosities, the
presence of powerful jets dominates the radio emission of these sources. A
positive correlation is found between the luminosity of the AGN component and
that of star-formation in the host galaxy, independent of the radio luminosity.
By contrast, for a given redshift and AGN luminosity, we find that increasing
radio-luminosity leads to a decrease in the specific star-formation rate. The
most radio-loud AGN are found to lie on the main sequence of star-formation for
their respective redshifts. For the first time, such a two-sided feedback
process is seen in the same sample. We conclude that radio jets do suppress
star-formation in their host galaxies but appear not to totally quench it. Our
results therefore support the maintenance nature of "radio-mode" feedback from
radio-AGN jets.


title: Lyman-alpha Forest Constraints on Decaying Dark Matter

abstract:
  We present an analysis of high-resolution N-body simulations of decaying dark
matter cosmologies focusing on the statistical properties of the transmitted
Lyman-alpha forest flux in the high-redshift intergalactic medium. In this type
of model a dark matter particle decays into a slightly less massive stable dark
matter daughter particle and a comparably light particle. The small mass
splitting provides a non-relativistic kick velocity V_k to the daughter
particle resulting in free-streaming and subsequent damping of small-scale
density fluctuations. Current Lyman-alpha forest power spectrum measurements
probe comoving scales up to ~ 2-3 h^-1 Mpc at redshifts z ~ 2-4, providing one
of the most robust ways to probe cosmological density fluctuations on
relatively small scales. The suppression of structure growth due to the
free-streaming of dark matter daughter particles also has a significant impact
on the neutral hydrogen cloud distribution, which traces the underlying dark
matter distribution well at high redshift. We exploit Lyman-alpha forest power
spectrum measurements to constrain the amount of free-streaming of dark matter
in such models and thereby place limits on decaying dark matter based only on
the dynamics of cosmological perturbations without any assumptions about the
interactions of the decay products. We find that SDSS 1D Lyman-alpha forest
power spectrum data place a lifetime-dependent upper limit V_k < 30-70 km/s for
decay lifetimes < 10 Gyr. This is the most stringent model-independent bound on
invisible dark matter decays with small mass splittings. For large mass
splittings (large V_k), Lyman-alpha forest data restrict the dark matter
lifetime to Gamma^-1 > 40 Gyr. Forthcoming BOSS data should be able to provide
more stringent constraints on exotic dark matter, mainly because the larger
BOSS quasar spectrum sample will significantly reduce statistical errors.


title:
Massive stars in massive clusters IV: Disruption of clouds by
  momentum-driven winds

abstract:
  We examine the effect of momentum-driven OB-star stellar winds on a parameter
space of simulated turbulent Giant Molecular Clouds using SPH hydrodynamical
simulations. By comparison with identical simulations in which ionizing
radiation was included instead of winds, we show that momentum-driven winds are
considerably less effective in disrupting their host clouds than are HII
regions. The wind bubbles produced are smaller and generally smoother than the
corresponding ionization-driven bubbles. Winds are roughly as effective in
destroying the very dense gas in which the O-stars are embedded, and thus
shutting down the main regions of star-forming activity in the model clouds.
However, their influence falls off rapidly with distance from the sources, so
they are not as good at sweeping up dense gas and triggering star formation
further out in the clouds. As a result, their effect on the star formation rate
and efficiency is generally more negative than that of ionization, if they
exert any effect at all.


title: Invariants and rigidity of projective hypersurfaces

abstract:
  This paper continues our researches \cite{DS1, DS2, DS3} by computing some
invariants based on Hilbert-Poincar\'{e} series associated to Milnor algebras.
Our computations are for some of the classical surfaces and 3-folds with
different configurations of isolated singularities. As a by-product of a recent
result of E. Sernesi, we give examples of classical hypersurfaces which are (or
are not) projectively rigid. We also include a Singular program to compute the
invariants and to decide if a singular projective hypersurface is nodal and
projectively rigid.


title:
Dynamics of current-carrying string loops in the Kerr naked-singularity
  and black-hole spacetimes

abstract:
  Current-carrying string-loop dynamics is studied in the Kerr spacetimes. With
attention concentrated to the axisymmetric motion of string loops around
symmetry axis of both black-hole (BH) and naked singularity (NS) spacetimes, it
is shown that the resulting motion is governed by the presence of an outer
tension barrier and an inner angular momentum barrier that are influenced by
the BH or NS spin. We classify the string dynamics according to properties of
the energy boundary function (effective potential) for the string loop motion.
We have found that for NS there exist new types of energy boundary function,
namely those with off-equatorial minima. Conversion of the energy of the string
oscillations to the energy of the linear translational motion has been studied.
Such a transmutation effect is much more efficient in the NS spacetimes because
lack of the event horizon. For BH spacetimes efficiency of the transmutation
effect is only weakly spin dependent. Transition from regular to chaotic regime
of the string-loop dynamics is examined and used for explanation of the
string-loop motion focusing problem. Radial and vertical frequencies of small
oscillations of string loops near minima of the effective potential in the
equatorial plane are given. These can be related to high-frequency
quasi-periodic oscillations observed near black holes.


title:
The rapidity dependence of the average transverse momentum in p+Pb
  collisions at the LHC: the Color Glass Condensate versus hydrodynamics

abstract:
  We show that in proton-lead (p+Pb) collisions at the LHC, the Color Glass
Condensate (CGC) and hydrodynamics lead to qualitatively different behavior of
the average transverse momentum, <p_T>, with the particles rapidity. In
hydrodynamics, the <p_T> decreases as one goes from zero rapidity, y=0, to the
proton fragmentation region since the number of particles decreases. In
contrast, in the CGC the saturation momentum increases as one goes from y=0 to
the proton fragmentation region, and so the <p_T> increases. At the LHC, the
difference between the two models may be large enough to be tested
experimentally.


title: Production of very-high-$n$ strontium Rydberg atoms

abstract:
  The production of very-high-$n$, $n\sim300$-500, strontium Rydberg atoms is
explored using a crossed laser-atom beam geometry. $n$$^{1}$S$_{0}$ and
$n$$^{1}$D$_{2}$ states are created by two-photon excitation via the 5s5p
$^{1}$P$_{1}$ intermediate state using radiation with wavelengths of $\sim$~461
and $\sim$ 413 nm. Rydberg atom densities as high as $\sim 3 \times 10^{5}$
cm$^{-3}$ have been achieved, sufficient that Rydberg-Rydberg interactions can
become important. The isotope shifts in the Rydberg series limits are
determined by tuning the 461 nm light to preferentially excite the different
strontium isotopes. Photoexcitation in the presence of an applied electric
field is examined. The initially quadratic Stark shift of the $n$$^{1}$P$_{1}$
and $n$$^{1}$D$_{2}$ states becomes near-linear at higher fields and the
possible use of $n{}^{1}$D$_{2}$ states to create strongly-polarized,
quasi-one-dimensional electronic states in strontium is discussed. The data are
analyzed with the aid of a two-active-electron (TAE) approximation. The
two-electron Hamiltonian, within which the Sr$^{2+}$ core is represented by a
semi-empirical potential, is numerically diagonalized allowing calculation of
the energies of high-$n$ Rydberg states and their photoexcitation
probabilities.


title:
An Interferometric Spectral-Line and Imaging Survey of VY Canis Majoris
  in the 345 GHz Band

abstract:
  A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was
made between 279 and 355 GHz with the Submillimeter Array. Two hundred twenty
three spectral features from 19 molecules (not counting isotopic species of
some of them) were observed, including the rotational spectra of TiO, TiO2, and
AlCl for the first time in this source. The parameters and an atlas of all
spectral features is presented. Observations of each line with a synthesized
beam of ~0.9 arcsec, reveal the complex kinematics and morphology of the nebula
surrounding VY CMa. Many of the molecules are observed in high lying rotational
levels or in excited vibrational levels. From these, it was established that
the main source of the submillimeter-wave continuum (dust) and the high
excitation molecular gas (the star) are separated by about 0.15 arcsec.
Apparent coincidences between the molecular gas observed with the SMA, and some
of the arcs and knots observed at infrared wavelengths and in the optical
scattered light by the Hubble Space Telescope are identified. The observations
presented here provide important constraints on the molecular chemistry in
oxygen-dominated circumstellar environments and a deeper picture of the complex
circumstellar environment of VY CMa.


title: The Stokes-Einstein Relation at Moderate Schmidt Number

abstract:
  The Stokes-Einstein relation for the self-diffusion coefficient of a
spherical particle suspended in an incompressible fluid is an asymptotic result
in the limit of large Schmidt number, that is, when momentum diffuses much
faster than the particle. When the Schmidt number is moderate, which happens in
most particle methods for hydrodynamics, deviations from the Stokes-Einstein
prediction are expected. We study these corrections computationally using a
recently-developed minimally-resolved method for coupling particles to an
incompressible fluctuating fluid in both two and three dimensions. We find that
for moderate Schmidt numbers the diffusion coefficient is reduced relative to
the Stokes-Einstein prediction by an amount inversely proportional to the
Schmidt number in both two and three dimensions. We find, however, that the
Einstein formula is obeyed at all Schmidt numbers, consistent with linear
response theory. The numerical data is in good agreement with an approximate
self-consistent theory, which can be used to estimate finite-Schmidt number
corrections in a variety of methods. Our results indicate that the corrections
to the Stokes-Einstein formula come primarily from the fact that the particle
itself diffuses together with the momentum. Our study separates effects coming
from corrections to no-slip hydrodynamics from those of finite separation of
time scales, allowing for a better understanding of widely observed deviations
from the Stokes-Einstein prediction in particle methods such as molecular
dynamics.


title:
Thermodynamics and magnetic properties of the anisotropic 3D Hubbard
  model

abstract:
  We study the 3D Hubbard model with anisotropic nearest neighbor tunneling
amplitudes using the dynamical cluster approximation and compare the results
with a quantum simulation experiment using ultracold fermions in an optical
lattice, focussing on magnetic correlations. We find that the short-range spin
correlations are significantly enhanced in the direction with stronger
tunneling amplitudes. Our results agree with the experimental observations and
show that the experimental temperature is lower than the strong tunneling
amplitude. We characterize the system by examining the spin correlations beyond
neighboring sites and determine the distribution of density, entropy and spin
correlation in the trapped system. We furthermore investigate the dependence of
the critical entropy at the N\'eel transition on anisotropy.


title:
Automorphism groups of certain rational hypersurfaces in complex
  four-space

abstract:
  The Russell cubic is a smooth contractible affine complex threefold which is
not isomorphic to affine three-space. In previous articles, we discussed the
structure of the automorphism group of this variety. Here we review some
consequences of this structure and generalize some results to other
hypersurfaces which arise as deformations of Koras-Russell threefolds.


title:
On the dynamics of WKB wave functions whose phase are weak KAM solutions
  of H-J equation

abstract:
  In the framework of toroidal Pseudodifferential operators on the flat torus
$\Bbb T^n := (\Bbb R / 2\pi \Bbb Z)^n$ we begin by proving the closure under
composition for the class of Weyl operators $\mathrm{Op}^w_\hbar(b)$ with
simbols $b \in S^m (\mathbb{T}^n \times \mathbb{R}^n)$. Subsequently, we
consider $\mathrm{Op}^w_\hbar(H)$ when $H=\frac{1}{2} |\eta|^2 + V(x)$ where $V
\in C^\infty (\Bbb T^n;\Bbb R)$ and we exhibit the toroidal version of the
equation for the Wigner transform of the solution of the Schr\"odinger
equation. Moreover, we prove the convergence (in a weak sense) of the Wigner
transform of the solution of the Schr\"odinger equation to the solution of the
Liouville equation on $\Bbb T^n \times \Bbb R^n$ written in the measure sense.
These results are applied to the study of some WKB type wave functions in the
Sobolev space $H^{1} (\mathbb{T}^n; \Bbb C)$ with phase functions in the class
of Lipschitz continuous weak KAM solutions (of positive and negative type) of
the Hamilton-Jacobi equation $\frac{1}{2} |P+ \nabla_x v_\pm (P,x)|^2 + V(x) =
\bar{H}(P)$ for $P \in \ell \Bbb Z^n$ with $\ell >0$, and to the study of the
backward and forward time propagation of the related Wigner measures supported
on the graph of $P+ \nabla_x v_\pm$.


title:
Rare-event Simulation and Efficient Discretization for the Supremum of
  Gaussian Random Fields

abstract:
  In this paper, we consider a classic problem concerning the high excursion
probabilities of a Gaussian random field $f$ living on a compact set $T$. We
develop efficient computational methods for the tail probabilities $P(\sup_T
f(t) > b)$ and the conditional expectations $E(\Gamma(f) | \sup_T f(t) > b)$ as
$b\rightarrow \infty$. For each $\varepsilon$ positive, we present Monte Carlo
algorithms that run in \emph{constant} time and compute the interesting
quantities with $\varepsilon$ relative error for arbitrarily large $b$. The
efficiency results are applicable to a large class of H\"older continuous
Gaussian random fields. Besides computations, the proposed change of measure
and its analysis techniques have several theoretical and practical indications
in the asymptotic analysis of extremes of Gaussian random fields.