title:
Fixed point theorems for $\alpha$--contractive mappings of Meir--Keeler
  type and applications

abstract:
  In this paper, we introduce the notion of $\alpha$--contractive mapping of
Meir--Keeler type in complete metric spaces and prove new theorems which assure
the existence, uniqueness and iterative approximation of the fixed point for
this type of contraction. The presented theorems extend, generalize and improve
several existing results in literature. To validate our results, we establish
the existence and uniqueness of solution to a class of third order two point
boundary value problems.


title: Gapless dual-comb spectroscopy in terahertz region

abstract:
  We demonstrated combination of gapless terahertz (THz) comb with dual-comb
spectroscopy, namely gapless dual-THz-comb spectroscopy, to achieve the
spectral resolution equal to width of the THz comb tooth. The gapless THz comb
was realized by interpolating frequency gaps between the comb teeth with
sweeping of a laser mode-locked frequency. The demonstration of low-pressure
gas spectroscopy with gapless dual-THz-comb spectroscopy clearly indicated that
the spectral resolution was decreased down to 2.5-MHz width of the comb tooth
and the spectral accuracy was enhanced to 10-6 within the spectral range of
1THz. The proposed method will be a powerful tool to simultaneously achieve
high resolution, high accuracy, and broad spectral coverage in THz
spectroscopy.


title: Line-Constrained Geometric Server Placement

abstract:
  In this paper we present new algorithmic solutions for several constrained
geometric server placement problems. We consider the problems of computing the
1-center and obnoxious 1-center of a set of line segments, constrained to lie
on a line segment, and the problem of computing the K-median of a set of
points, constrained to lie on a line. The presented algorithms have
applications in many types of distributed systems, as well as in various fields
which make use of distributed systems for running some of their applications
(like chemistry, metallurgy, physics, etc.).


title:
Integrating MBE materials with graphene to induce novel spin-based
  phenomena

abstract:
  Magnetism in graphene is an emerging field that has received much theoretical
attention. In particular, there have been exciting predictions for induced
magnetism through proximity to a ferromagnetic insulator as well as through
localized dopants and defects. Here, we discuss our experimental work using
molecular beam epitaxy (MBE) to modify the surface of graphene and induce novel
spin-dependent phenomena. First, we investigate the epitaxial growth the
ferromagnetic insulator EuO on graphene and discuss possible scenarios for
realizing exchange splitting and exchange fields by ferromagnetic insulators.
Second, we investigate the properties of magnetic moments in graphene
originating from localized p_z-orbital defects (i.e. adsorbed hydrogen atoms).
The behavior of these magnetic moments is studied using non-local spin
transport to directly probe the spin-degree of freedom of the defect-induced
states. We also report the presence of enhanced electron g-factors caused by
the exchange fields present in the system. Importantly, the exchange field is
found to be highly gate dependent, with decreasing g-factors with increasing
carrier densities.


title: Sparsity-leveraging Reconfiguration of Smart Distribution Systems

abstract:
  A system reconfiguration problem is considered for three-phase power
distribution networks featuring distributed generation. In lieu of binary line
selection variables, the notion of group sparsity is advocated to re-formulate
the nonconvex distribution system reconfiguration (DSR) problem into a convex
one. Using the duality theory, it is shown that the line selection task boils
down to a shrinkage and thresholding operation on the line currents. Further,
numerical tests illustrate the ability of the proposed scheme to identify
meshed, weakly-meshed, or even radial configurations by adjusting a
sparsity-tuning parameter in the DSR cost. Constraints on the voltages are
investigated, and incorporated in the novel DSR problem to effect voltage
regulation.


title:
Efficient Online Algorithmic Strategies for Several Two-Player Games
  with Different or Identical Player Roles

abstract:
  In this paper we introduce novel algorithmic strategies for effciently
playing two-player games in which the players have different or identical
player roles. In the case of identical roles, the players compete for the same
objective (that of winning the game). The case with different player roles
assumes that one of the players asks questions in order to identify a secret
pattern and the other one answers them. The purpose of the first player is to
ask as few questions as possible (or that the questions and their number
satisfy some previously known constraints) and the purpose of the secret player
is to answer the questions in a way that will maximize the number of questions
asked by the first player (or in a way which forces the first player to break
the constraints of the game). We consider both previously known games (or
extensions of theirs) and new types of games, introduced in this paper.


title:
Analysis of Bose-Einstein correlations at fixed multiplicities in TeV
  energy $pp$ collisions in the quantum optical approach

abstract:
  The multiplicity distribution and the two-particle Bose-Einstein correlations
at fixed multiplicities observed in $pp$ collisions at $\sqrt{s}=7$ TeV by the
ALICE Collaboration are analyzed by the formulae obtained in the quantum
optical approach. The chaoticity parameters in the inclusive and semi-inclusive
events are estimated from the analysis.
  Multiplicity or $k_T$ dependence of longitudinal and transverse source radii
are also estimated.


title: Optimal Placement of Distributed Energy Storage in Power Networks

abstract:
  We formulate the optimal placement, sizing and control of storage devices in
a power network to minimize generation costs with the intent of load shifting.
We assume deterministic demand, a linearized DC approximated power flow model
and a fixed available storage budget. Our main result proves that when the
generation costs are convex and nondecreasing, there always exists an optimal
storage capacity allocation that places zero storage at generation-only buses
that connect to the rest of the network via single links. This holds regardless
of the demand profiles, generation capacities, line-flow limits and
characteristics of the storage technologies. Through a counterexample, we
illustrate that this result is not generally true for generation buses with
multiple connections. For specific network topologies, we also characterize the
dependence of the optimal generation cost on the available storage budget,
generation capacities and flow constraints.


title: Positivity and tameness in rank 2 cluster algebras

abstract:
  We study the relationship between the positivity property in a rank 2 cluster
algebra, and the property of such an algebra to be tame. More precisely, we
show that a rank 2 cluster algebra has a basis of indecomposable positive
elements if and only if it is of finite or affine type. This statement
disagrees with a conjecture by Fock and Goncharov.


title:
Generalized Retrieval Method for Metamaterial Constitutive Parameters
  Based on a Physically-Driven Homogenization Approach

abstract:
  Based on the recently introduced homogenization theory developed in [Phys.
Rev. B 84, 075153 (2011)], we propose a generalized retrieval method that
allows extracting physically meaningful bulk effective parameters from
conventional scattering measurements of periodic metamaterial samples composed
of subwavelength inclusions. We show that, compared to conventional approaches,
our method is able to capture the anomalous physics in the wave interaction
with resonant metamaterials and return physically meaningful homogenized
parameters that retain local properties in the long-wavelength limit. As a
byproduct, we are also able to retrieve the polarizabilities of the constituent
inclusions, which are shown to satisfy expected dispersion properties for
passive inclusions, in contrast with conventional retrieval approaches.


title: Abstract loop equations, topological recursion, and applications

abstract:
  We formulate a notion of abstract loop equations, and show that their
solution is provided by a topological recursion under some assumptions, in
particular the result takes a universal form. The Schwinger-Dyson equation of
the one and two hermitian matrix models, and of the O(n) model appear as
special cases. We study applications to repulsive particles systems, and
explain how our notion of loop equations are related to Virasoro constraints.
Then, as a special case, we study in detail applications to enumeration
problems in a general class of non-intersecting loop models on the random
lattice of all topologies, to SU(N) Chern-Simons invariants of torus knots in
the large N expansion. We also mention an application to Liouville theory on
surfaces of positive genus.


title:
Volatility Inference in the Presence of Both Endogenous Time and
  Microstructure Noise

abstract:
  In this article we consider the volatility inference in the presence of both
market microstructure noise and endogenous time. Estimators of the integrated
volatility in such a setting are proposed, and their asymptotic properties are
studied. Our proposed estimator is compared with the existing popular
volatility estimators via numerical studies. The results show that our
estimator can have substantially better performance when time endogeneity
exists.


title: Diphoton Decay Excess and 125 GeV Higgs Boson in Gauge-Higgs Unification

abstract:
  In the context of gauge-Higgs unification scenario in a 5-dimensional flat
spacetime, we investigate Higgs boson production via gluon fusion and its
diphoton decay mode at the LHC. We show that the signal strength of the Higgs
diphoton decay mode observed at ATLAS and CMS, which is considerably larger
than the Standard Model expectation, can be explained by a simple gauge-Higgs
unification model with color-singlet bulk fermions to which a half-periodic
boundary condition is assigned. The bulk fermions also play a crucial role in
reproducing the observed Higgs boson mass around 125 GeV.


title:
Thermorheological Complexity in Polymers and the Problem of the Glass
  Transition

abstract:
  A current focus in studies of the glass transition is the role of dynamic
heterogeneities. Although these efforts may clarify the origin of the
spectacular change in properties of liquids approaching vitrification, we point
out that a seemingly related phenomenon, thermorheological complexity in
polymers, must involve different mechanisms. In particular, as seen from
consideration of various properties involving the chain dynamics, averaging
over different length and time scales cannot offer a resolution to the problem
of thermorheological complexity.


title: On the accretion disc and evolutionary stage of beta Lyrae

abstract:
  We modeled the V-band light curve of beta Lyrae with two stellar components
plus an optically thick accretion disc around the gainer assuming a
semidetached configuration. We present the results of this calculation, giving
physical parameters for the stars and the disc, along with general system
dimensions. We discuss the evolutionary stage of the system finding the best
match with one of the evolutionary models of Van Rensbergen et al. According to
this model, the system is found at age 2.30E7 years, in the phase of rapid mass
transfer, the second one in the life of this binary, in a Case-B mass-exchange
stage with dM/dt = 1.58E-5 Msun/year. This result, along with the reported rate
of orbital period change and observational evidence of mass loss, suggests that
the mass transfer in beta Lyrae, is quasi-conservative. The best model
indicates that beta Lyrae finished a relatively large mass loss episode 31400
years ago. The light curve model that best fit the observations has inclination
angle i = 81 degree, M1 = 13.2 Msun, M2 = 3.0 Msun, R1 = 6.0 Rsun and R2 = 15.2
Rsun. The disc contributes 22% to the total V-band light curve at quadrature,
has a radius of 28.3 Rsun and the outer edge thickness is 11.2 Rsun. The light
curve model is significantly better with two bright regions in the disc rim
with temperatures 10% and 20% higher than the disc outer edge temperature. We
compare our results with earlier studies of this interacting binary.


title:
Emergence of spaces and the dynamic equations of FRW universes in the
  $f(R)$ theory and deformed Ho\v{r}ava-Lifshitz theory

abstract:
  It has been shown that Friedmann equation of FRW universe can be derived from
the idea which says cosmic space is emergent as cosmic time progresses and our
universe is expanding towards the state with the holographic equipartition by
Padmanabhan. In this note, we give a general relationship between the horizon
entropy and the number of the degrees of freedom on the surface, we also obtain
the corresponding dynamic equations by using the idea of emergence of space in
the $f(R)$ theory and deformed Ho\v{r}ava-Lifshitz (HL) theory.


title:
Optimum laser intensity for the production of energetic deuterium ions
  from laser-cluster interaction

abstract:
  We measured, using Petawatt-level pulses, the average ion energy and neutron
yield in high-intensity laser interactions with molecular clusters as a
function of laser intensity. The interaction volume over which fusion occurred
(1-10 mm^3) was larger than previous investigations, owing to the high laser
power. Possible effects of prepulses were examined by implementing a pair of
plasma mirrors. Our results show an optimum laser intensity for the production
of energetic deuterium ions both with and without the use of the plasma
mirrors. We measured deuterium plasmas with 14 keV average ion energies, which
produced 7.2x10^6 and 1.6x10^7 neutrons in a single shot with and without
plasma mirrors, respectively. The measured neutron yields qualitatively matched
the expected yields calculated using a cylindrical plasma model.


title:
Qubit-mediated energy transfer between thermal reservoirs: beyond
  Markovian Master equation

abstract:
  We study qubit-mediated energy transfer between two electron reservoirs by
adopting a numerically-exact influence functional path-integral method. This
non-perturbative technique allows us to study the system's dynamics beyond the
weak coupling limit. Our simulations for the energy current indicate that
perturbative-Markovian Master equation predictions significantly deviate from
exact numerical results already at intermediate coupling, $\pi \rho
\alpha_{j,j'}\gtrsim 0.4$, where $\rho$ is the metal (Fermi sea) density of
states, taken as a constant, and $\alpha_{j,j'}$ is the scattering potential
energy of electrons, between the $j$ and $j'$ states. Markovian Master equation
techniques should be therefore used with caution beyond the strictly weak
subsystem-bath coupling limit, especially when a quantitative knowledge of
transport characteristics is desired.


title: Random fusion frames are nearly equiangular and tight

abstract:
  This paper demonstrates that random, independently chosen equi-dimensional
subspaces with a unitarily invariant distribution in a real Hilbert space
provide nearly tight, nearly equiangular fusion frames. The angle between a
pair of subspaces is measured in terms of the Hilbert-Schmidt inner product of
the corresponding orthogonal projections. If the subspaces are selected at
random, then a measure concentration argument shows that these inner products
concentrate near an average value. Overwhelming success probability for near
tightness and equiangularity is guaranteed if the dimension of the subspaces is
sufficiently small compared to that of the Hilbert space and if the dimension
of the Hilbert space is small compared to the sum of all subspace dimensions.


title: Assumptionless consistency of the Lasso

abstract:
  The Lasso is a popular statistical tool invented by Robert Tibshirani for
linear regression when the number of covariates is greater than or comparable
to the number of observations. The purpose of this note is to highlight the
simple fact (noted in a number of earlier papers in various guises) that for
the loss function considered in Tibshirani's original paper, the Lasso is
consistent under almost no assumptions at all.


title:
Common properties of bounded linear operators $AC$ and $BA$: Spectral
  theory

abstract:
  Let $X,Y$ be Banach spaces, $A:X \longrightarrow Y$ and $B,C:Y
\longrightarrow X$ be bounded linear operators satisfying operator equation
$ABA=ACA$. Recently, as extensions of Jacobson's lemma, Corach, Duggal and
Harte studied common properties of $AC-I$ and $BA-I$ in algebraic viewpoint and
also obtained some topological analogues. In this note, we continue to
investigate common properties of $AC$ and $BA$ from the viewpoint of spectral
theory. In particular, we give an affirmative answer to one question posed by
Corach et al. by proving that $AC - I$ has closed range if and only if $BA - I$
has closed range.


title: The Nature of Massive Neutrinos

abstract:
  The compelling experimental evidences for oscillations of solar, reactor,
atmospheric and accelerator neutrinos imply the existence of 3-neutrino mixing
in the weak charged lepton current. The current data on the 3-neutrino mixing
parameters are summarised and the phenomenology of 3-$\nu$ mixing is reviewed.
The properties of massive Majorana neutrinos and of their various possible
couplings are discussed in detail. Two models of neutrino mass generation with
massive Majorana neutrinos - the type I see-saw and the Higgs triplet model,
are briefly reviewed. The problem of determining the nature - Dirac or
Majorana, of massive neutrinos is considered. The predictions for the effective
Majorana mass $\meff$ in neutrinoless double beta ($\betabeta-$) decay in the
case of 3-neutrino mixing and massive Majorana neutrinos are summarised. The
physics potential of the experiments, searching for $\betabeta-$decay for
providing information on the type of the neutrino mass spectrum, on the
absolute scale of neutrino masses and on the Majorana CP-violation phases in
the PMNS neutrino mixing matrix, is also briefly discussed. The opened
questions and the main goals of future research in the field of neutrino
physics are outlined.


title: Recurrence Relations of the Multi-Indexed Orthogonal Polynomials

abstract:
  Ordinary orthogonal polynomials are uniquely characterized by the three term
recurrence relations up to an overall multiplicative constant. We show that the
newly discovered M-indexed orthogonal polynomials satisfy 3+2M term recurrence
relations with non-trivial initial data of the lowest M+1 members. These
include the multi-indexed orthogonal polynomials of Laguerre, Jacobi, Wilson
and Askey-Wilson types. The M=0 case is the corresponding classical orthogonal
polynomials.

categories: math-ph hep-th math.CA math.MP nlin.SI quant-ph


title:
Experimental characterization of the stagnation layer between two
  obliquely merging supersonic plasma jets

abstract:
  We present spatially resolved measurements characterizing the stagnation
layer between two obliquely merging supersonic plasma jets. Intra-jet
collisionality is very high ($\lambda_{ii} \ll 1$mm), but the inter-jet ion-ion
mean free paths are on the same order as the stagnation layer thickness (a few
cm). Fast-framing camera images show a double-peaked emission profile
transverse to the stagnation layer, with the central emission dip consistent
with a density dip observed in the interferometer data. We demonstrate that our
observations are consistent with collisional oblique shocks.


title:
Lower bounds on the number of rational points of Jacobians over finite
  fields and application to algebraic function fields in towers

abstract:
  We give effective bounds for the class number of any algebraic function field
of genus $g$ defined over a finite field. These bounds depend on the possibly
partial information on the number of places on each degree $\leq g$. Such
bounds are especially useful for estimating the class number of function fields
in towers of function fields over finite fields. We give examples in the case
of asymptotically good towers. In particular we estimate the class number of
function fields which are steps of towers having one or several positive
Tsfasman-Vladut invariants. Note that the study is not done asymptotically, but
for each individual step of the towers for which we determine precise
parameters.


title: Nanophotonic Computational Design

abstract:
  In contrast to designing nanophotonic devices by tuning a handful of device
parameters, we have developed a computational method which utilizes the full
parameter space to design linear nanophotonic devices. We show that our method
may indeed be capable of designing any linear nanophotonic device by
demonstrating designed structures which are fully three-dimensional and
multi-modal, exhibit novel functionality, have very compact footprints, exhibit
high efficiency, and are manufacturable. In addition, we also demonstrate the
ability to produce structures which are strongly robust to wavelength and
temperature shift, as well as fabrication error. Critically, we show that our
method does not require the user to be a nanophotonic expert or to perform any
manual tuning. Instead, we are able to design devices solely based on the users
desired performance specification for the device.


title:
Interplay and competition between superconductivity and charge orderings
  in the zero-bandwidth limit of the extended Hubbard model with pair hopping
  and on-site attraction

abstract:
  We present studies of an effective model which is a simple generalization of
the standard model of a local pair superconductor with on-site pairing (i.e.,
the model of hard core bosons on a lattice) to the case of finite pair binding
energy. The tight binding Hamiltonian consists of (i) the effective on-site
interaction U, (ii) the intersite density-density interactions W between
nearest-neighbours, and (iii) the intersite charge exchange term I, determining
the hopping of electron pairs between nearest-neighbour sites. In the analysis
of the phase diagrams and thermodynamic properties of this model we treat the
intersite interactions within the mean-field approximation. Our investigations
of the U<0 and W>0 case show that, depending on the values of interaction
parameters, the system can exhibit three homogeneous phases: superconducting
(SS), charge-ordered (CO) and nonordered (NO) as well as the phase separated
SS-CO state.


title: Semileptonic Decays of Pseudoscalar Mesons: A New Approach

abstract:
  Because quarks in hadronic states are subjected to strong QCD forces, it is
not straight-forward to apply calculation obtained at the quark level to
physical processes involving hadrons. In this paper we present a new approach
to treat the semileptonic decays of pseudoscalar mesons. At the quark level,
the process is straightforward. However, when we fold the quark-level process
to the meson decay process, the complication from QCD effects come in. We make
the fundamental assumption that the vertex of type M-q-qbar can be approximated
by an effective constant gamma-5 coupling. With this assumption, the hadronic
process can then be related to the quark-level process. The model is applied to
the semileptonic decays of pi, K, D and B mesons.


title:
Collective Quantum Dot Inversion and Amplification of Photon and Phonon
  Waves

abstract:
  The possibility of steady-state population inversion in a small sample of
strongly driven two-level emitters like quantum dots (QDs) in micro-cavities,
and its utilization towards amplification of light and acoustic waves is
investigated theoretically. We find that inversion and absorption spectrum of
photons, and phonons crucially depend on the interplay between the intrinsic
vacuum and phonon environments. The absorption profiles of photons and phonons
show marked novel features like gain instead of transparency and absorption
reversed to gain, respectively. Furthermore, we report collectivity induced
substantial enhancement of inversion and pronounced gain in the photon, and
phonon absorption spectrum for a wavelength size QD ensemble.


title: Decay Constants of Pseudoscalar Mesons

abstract:
  For purely leptonic decays of pseudoscalar mesons, the decay rates are
related to the product of the relevant weak interaction-based CKM matrix
element of the constituent quarks on the one hand, and the strong interaction
parameter, the decay constant, which is related to the overlap of the quark and
antiquark in the meson on the other hand. The decay constants for these mesons
can thus be estimated from the decay rates of the respective dominant decay
modes. The decay constants so obtained are used to estimate the decay rates of
the less dominant modes, which are in good agreement with experimentally
measured values. We also predict the decay rates for tau-lepton.


title: The dynamics of Bianchi I universes in $R^n$ cosmologies with torsion

abstract:
  We analyze the phase space of Bianchi I cosmologies filled by a spin fluid in
the framework of $f(R)$-gravity with torsion using a combination of the
dynamical systems approach and the 1+3 covariant formalism. In the simple case
of $f(R)=R^n$ our results allow a quantification of the role of torsion and the
spin of the cosmic fluid in the evolution of the cosmology. While torsion is
able to modify the cosmological dynamics with respect to the purely metric
case, the spin has little influence on the cosmology. We argue that this is due
to the different symmetries of the tensor characterizing the anisotropies and
the spin tensor. The cosmological model we analyzed presents isotropization for
a wide set of initial conditions and values of the parameters and allows for
two types of exotic bounce solutions.


title:
Integrability of potentials of degree $k \neq \pm 2$. Second order
  variational equations between Kolchin solvability and Abelianity

abstract:
  In our previous paper: Integrability of Homogeneous potentials of degree $k =
\pm 2$. An application of higher order variational equations, we tried to
extract some particular structures of the higher variational equations (the
${VE}_p$ for $p >1 $), along particular solutions of some Hamiltonian systems.
Then, we use them to get new Galois obstructions to the integrability of
natural Hamiltonian with potential of degree $k = \pm 2$. In the present work,
we apply the results of the previous paper, to the complementary cases, when
the degrees of the potentials are relative integers $k$, with $|k| >2$. Since
these cases are much more general and complicated, we reduce our study only to
the second variational equation ${VE}_2$.


title:
Reconciling the Muon g-2 and Dark Matter Relic Density with the LHC
  Results in Nonuniversal Gaugino Mass Models

abstract:
  Relatively light electroweak superparticle masses are required to satisfy the
bulk annihilation region of dark matter relic density and account for the
observed excess of muon g-2, while TeV scale squark and gluino masses are
required to account for the 125 GeV Higgs boson mass and the negative SUSY
search results from LHC. These two sets of requirements can be reconciled in a
simple nonuniversal gaugino mass model, which assumes SUSY breaking via a
combination of two superfields belonging to the singlet and the 200-plet
representations of the GUT group SU(5). The model can be probed via
squark/gluon search with the present and future LHC data. In a more general
nonuniversal gaugino mass model the squark and gluino masses can be raised to
the edge of the discovery limit of LHC or beyond. This model can be probed,
however, through the search for electroweak pair production of the relatively
light sleptons and winos with the future LHC data.


title: Transient dynamics of open quantum systems

abstract:
  We present a renormalization group (RG) method which allows for an analytical
study of the transient dynamics of open quantum systems on all time scales.
Whereas oscillation frequencies and decay rates of exponential time evolution
follow from the fixed point positions, the long-time behavior of
pre-exponential functions is related to the scaling behavior around the fixed
points. We show that certain terms of the RG flow are only cut off by inverse
time, which leads to a difference between infrared and ultraviolet scaling. An
evaluation for the ohmic spin boson model at weak damping reveals significant
deviations from previous predictions in the long-time regime. We propose that
weak coupling problems for stationary quantities can in principle turn into
strong coupling ones for the determination of the long-time behavior.


title:
Metrizable isotropic second-order differential equations and Hilbert's
  fourth problem

abstract:
  It is well known that a system of homogeneous second-order ordinary
differential equations (spray) is necessarily isotropic in order to be
metrizable by a Finsler function of scalar flag curvature. In Theorem 3.1 we
show that the isotropy condition, together with three other conditions on the
Jacobi endomorphism, characterize sprays that are metrizable by Finsler
functions of scalar flag curvature. The proof of Theorem 3.1 provides an
algorithm to construct the Finsler function of scalar flag curvature, in the
case when a given spray is metrizable. One condition of Theorem 3.1, regarding
the regularity of the sought after Finsler function, can be relaxed. By
relaxing this condition, we provide examples of sprays that are metrizable by
conic pseudo-Finsler functions as well as degenerate Finsler functions.
  Hilbert's fourth problem asks to determine the Finsler functions with
rectilinear geodesics. A Finsler function that is a solution to Hilbert's
fourth problem is necessarily of constant or scalar flag curvature. Therefore,
we can use the conditions of [11, Theorem 4.1] and Theorem 3.1 to test when the
projective deformations of a flat spray, which are isotropic, are metrizable by
Finsler functions of constant or scalar flag curvature. We show how to use the
algorithms provided by the proofs of [11, Theorem 4.1] and Theorem 3.1 to
construct solutions to Hilbert's fourth problem.


title: On the mathematical treatment of the Born-Oppenheimer approximation

abstract:
  Motivated by a paper by B.T. Sutcliffe and R.G. Woolley, we present the main
ideas used by mathematicians to show the accuracy of the Born-Oppenheimer
approximation for molecules. Based on mathematical works on this approximation
for molecular bound states, in scattering theory, in resonance theory, and for
short time evolution, we give an overview of some rigourous results obtained up
to now. We also point out the main difficulties mathematicians are trying to
overcome and speculate on further developments. The mathematical approach does
not fit exactly to the common use of the approximation in Physics and
Chemistry. We criticize the latter and comment on the differences, contributing
in this way to the discussion on the Born-Oppenheimer approximation initiated
by B.T. Sutcliffe and R.G. Woolley. The paper neither contains mathematical
statements nor proofs. Instead we try to make accessible mathematically
rigourous results on the subject to researchers in Quantum Chemistry or
Physics.


title: Generalised canonical basic sets for Ariki-Koike algebras

abstract:
  Let H be a non semi-simple Ariki-Koike algebra. According to [18] and [14],
there is a generalisation of Lusztig's a-function which induces a natural order
(parametrised by a tuple m) on Specht modules. In some cases, Geck and Jacon
have proved that this order makes unitriangular the decomposition matrix of H.
The algebra H is then said to admit a "canonical basic set". We fully classify
which values of m afford a canonical basic set for H and which do not. When
this is the case, we describe these sets in terms of "twisted Uglov" or
"twisted Kleshchev" multipartitions.


title:
Forward-Backward Stochastic Differential Equations and Controlled McKean
  Vlasov Dynamics

abstract:
  The purpose of this paper is to provide a detailed probabilistic analysis of
the optimal control of nonlinear stochastic dynamical systems of the McKean
Vlasov type. Motivated by the recent interest in mean field games, we highlight
the connection and the differences between the two sets of problems. We prove a
new version of the stochastic maximum principle and give sufficient conditions
for existence of an optimal control. We also provide examples for which our
sufficient conditions for existence of an optimal solution are satisfied.
Finally we show that our solution to the control problem provides approximate
equilibria for large stochastic games with mean field interactions.


title:
Equivalence between duality and gradient flow solutions for
  one-dimensional aggregation equations

abstract:
  Existence and uniqueness of global in time measure solution for a one
dimensional nonlinear aggregation equation is considered. Such a system can be
written as a conservation law with a velocity field computed through a
selfconsistant interaction potential. Blow up of regular solutions is now well
established for such system. In Carrillo et al. (Duke Math J (2011)), a theory
of existence and uniqueness based on the geometric approach of gradient flows
on Wasserstein space has been developped. We propose in this work to establish
the link between this approach and duality solutions. This latter concept of
solutions allows in particular to define a flow associated to the velocity
field. Then an existence and uniqueness theory for duality solutions is
developped in the spirit of James and Vauchelet (NoDEA (2013)). However, since
duality solutions are only known in one dimension, we restrict our study to the
one dimensional case.


title:
Multilevel communication optimal LU and QR factorizations for
  hierarchical platforms

abstract:
  This study focuses on the performance of two classical dense linear algebra
algorithms, the LU and the QR factorizations, on multilevel hierarchical
platforms. We first introduce a new model called Hierarchical Cluster Platform
(HCP), encapsulating the characteristics of such platforms. The focus is set on
reducing the communication requirements of studied algorithms at each level of
the hierarchy. Lower bounds on communications are therefore extended with
respect to the HCP model. We then introduce multilevel LU and QR algorithms
tailored for those platforms, and provide a detailed performance analysis. We
also provide a set of numerical experiments and performance predictions
demonstrating the need for such algorithms on large platforms.


title:
Circular law for random matrices with unconditional log-concave
  distribution

abstract:
  We explore the validity of the circular law for random matrices with non
i.i.d. entries. Let A be a random n \times n real matrix having as a random
vector in R^{n^2} a log-concave isotropic unconditional law. In particular, the
entries are uncorellated and have a symmetric law of zero mean and unit
variance. This allows for some dependence and non equidistribution among the
entries, while keeping the special case of i.i.d. standard Gaussian entries.
Our main result states that as n goes to infinity, the empirical spectral
distribution of n^{-1/2}A tends to the uniform law on the unit disc of the
complex plane.


title:
Clustering Based Lifetime Maximizing Aggregation Tree for Wireless
  Sensor Networks

abstract:
  Energy efficiency is the most important issue in all facets of wireless
sensor networks (WSNs) operations because of the limited and non-replenish able
energy supply. Data aggregation mechanism is one of the possible solutions to
prolong the life time of sensor nodes and on the other hand it also helps in
eliminating the data redundancy and improving the accuracy of information
gathering, is essential for WSNs. In this paper we propose a Clustering based
lifetime maximizing aggregation tree (CLMAT) in which we create aggregation
tree which aim to reduce energy consumption, minimizing the distance traversed
and minimizing the cost in terms of energy consumption. In CLMAT the node
having maximum available energy is used as parent node/ aggregator node. We
concluded with the best possible aggregation tree minimizing energy
utilization, minimizing cost and hence maximizing network lifetime.


title:
Hamilton-Jacobi Theorems for Regular Reducible Hamiltonian Systems on a
  Cotangent Bundle

abstract:
  In this paper, some of formulations of Hamilton-Jacobi equations for
Hamiltonian system and regular reduced Hamiltonian systems are given. At first,
an important lemma is proved, and it is a modification for the corresponding
result of Abraham and Marsden in [1], such that we can prove two types of
geometric Hamilton-Jacobi theorem for a Hamiltonian system on the cotangent
bundle of a configuration manifold, by using the symplectic structure and
dynamical vector field. Then these results are generalized to the regular
reducible Hamiltonian system with symmetry and momentum map, by using the
reduced symplectic structure and the reduced dynamical vector field. The
Hamilton-Jacobi theorems are proved and two types of Hamilton-Jacobi equations,
for the regular point reduced Hamiltonian system and the regular orbit reduced
Hamiltonian system, are obtained. As an application of the theoretical results,
the regular point reducible Hamiltonian system on a Lie group is considered,
and two types of Lie-Poisson Hamilton-Jacobi equation for the regular point
reduced system are given. In particular, the Type I and Type II of Lie-Poisson
Hamilton-Jacobi equations for the regular point reduced rigid body and heavy
top systems are shown, respectively.


title:
Adaptive-Gain Second Order Sliding Mode Observer Design for Switching
  Power Converters

abstract:
  In this paper, a novel adaptive-gain Second Order Sliding Mode (SOSM)
observer is proposed for multicell converters by considering it as a class of
hybrid systems. The aim is to reduce the number of voltage sensors by
estimating the capacitor voltages only from the measurement of load current.
The proposed observer is proven to be robust in the presence of perturbations
with \emph{unknown} boundary. However, the states of the system are only
partially observable in the sense of observability rank condition. Due to its
switching behavior, a recent concept of $Z(T_N)$ observability is used to
analysis its hybrid observability, since its observability depends upon the
switching control signals. Under certain condition of the switching sequences,
the voltage across each capacitor becomes observable. Simulation results and
comparisons with Luenberger switched observer highlight the effectiveness and
robustness of the proposed observer with respect to output measurement noise
and system uncertainties (load variations).


title:
Observer-Based High Order Sliding Mode Control of Unity Power Factor in
  Three-Phase AC/DC Converter for Hybrid Electric Vehicle Applications

abstract:
  In this paper, a full-bridge boost power converter topology is studied for
power factor control, using output high order sliding mode control. The AC/DC
converters are used for charging the battery and super-capacitor in hybrid
electric vehicles from the utility. The proposed control forces the input
currents to track the desired values, which can controls the output voltage
while keeping the power factor close to one. Super-twisting sliding mode
observer is employed to estimate the input currents and load resistance only
from the measurement of output voltage. Lyapunov analysis shows the asymptotic
convergence of the closed loop system to zero. Simulation results show the
effectiveness and robustness of the proposed controller.


title:
Stringent constraint on neutrino Lorentz-invariance violation from the
  two IceCube PeV neutrinos

abstract:
  It has been speculated that Lorentz-invariance violation (LIV) might be
generated by quantum-gravity (QG) effects. As a consequence, particles may not
travel at the universal speed of light. In particular, superluminal
extragalactic neutrinos would rapidly lose energy via the bremssthralung of
electron-positron pairs (nu -> nu e+ e-), damping their initial energy into
electromagnetic cascades, a figure constrained by Fermi-LAT data. We show that
the two cascade neutrino events with energies around 1 PeV recently detected by
IceCube -if attributed to extragalactic diffuse events, as it appears likely-
can place the strongest bound on LIV in the neutrino sector, namely delta
=(v^2-1) < O(10^(-18)), corresponding to a QG scale M_QG ~ 10^5 M_Pl (M_QG >~
10^(-4) M_Pl) for a linear (quadratic) LIV, at least for models inducing
superluminal neutrino effects (delta > 0).


title: Correlations and Scaling Laws in Human Mobility

abstract:
  Human mobility patterns deeply affect the dynamics of many social systems. In
this paper, we empirically analyze the real-world human movements based GPS
records, and observe rich scaling properties in the temporal-spatial patterns
as well as an abnormal transition in the speed-displacement patterns. We notice
that the displacements at the population level show significant positive
correlation, indicating a cascade-like nature in human movements. Furthermore,
our analysis at the individual level finds that the displacement distributions
of users with strong correlation of displacements are closer to power laws,
implying a relationship between the positive correlation of the series of
displacements and the form of an individual's displacement distribution. These
findings from our empirical analysis show a factor directly relevant to the
origin of the scaling properties in human mobility.


title:
Jackson kernels: a tool for analyzing the decay of eigenvalue sequences
  of integral operators on the sphere

abstract:
  Decay rates for the sequence of eigenvalues of positive and compact integral
operators has been largely investigated for a long time in the literature. In
this paper, the focus will be on positive integral operators acting on square
integrable functions on the unit sphere and generated by a kernel satisfying a
H\"older type assumption defined via average operators. In the approach to be
presented here, the decay rates will be reached from convenient estimations on
the eigenvalues of the operator themselves, with the help of specific
properties of a generic approximation operator defined through the so-called
generalized Jackson kernels. The decay rates have the same structure of those
known to hold in the cases in which the H\"older condition is the classical
one. Therefore, within the spherical setting, the abstract approach to be
introduced here extends some classical results on the topic.


title:
Smoothness and singularities of the perfect form and the second Voronoi
  compactification of ${\mathcal A}_g$

abstract:
  We study the cones in the first Voronoi or perfect cone decomposition of
quadratic forms with respect to the question which of these cones are basic or
simplicial. As a consequence we deduce that the singular locus of the moduli
stack ${\mathcal A_g^{\mathop{Perf}}}$, the toroidal compactification of the
moduli space of principally polarized abelian varieties of dimension $g$ given
by this decomposition, has codimension $10$ if $g \geq 4$. Moreover we describe
the non-simplicial locus in codimension $10$. We also show that the second
Voronoi compactification ${\mathcal A_{g}^{\mathop{Vor}}}$ has singularities in
codimension $3$ for $g\geq 5$.


title: Equivalence of the categories of modules over Lie algebroids

abstract:
  We study geometric representation theory of Lie algebroids. A new equivalence
relation for integrable Lie algebroids is introduced and investigated. It is
shown that two equivalent Lie algebroids have equivalent categories of
infinitesimal actions of Lie algebroids. As an application, it is also shown
that the Hamiltonian categories for gauge equivalent Dirac structures are
equivalent as categories.


title: A general moment expansion method for stochastic kinetic models

abstract:
  Moment approximation methods are gaining increasing attention for their use
in the approximation of the stochastic kinetics of chemical reaction systems.
In this paper we derive a general moment expansion method for any type of
propensities and which allows expansion up to any number of moments. For some
chemical reaction systems, more than two moments are necessary to describe the
dynamic properties of the system, which the linear noise approximation (LNA) is
unable to provide. Moreover, also for systems for which the mean does not have
a strong dependence on higher order moments, moment approximation methods give
information about higher order moments of the underlying probability
distribution. We demonstrate the method using a dimerisation reaction,
Michaelis-Menten kinetics and a model of an oscillating p53 system. We show
that for the dimerisation reaction and Michaelis-Menten enzyme kinetics system
higher order moments have limited influence on the estimation of the mean,
while for the p53 system, the solution for the mean can require several moments
to converge to the average obtained from many stochastic simulations. We also
find that agreement between lower order moments does not guarantee that higher
moments will agree. Compared to stochastic simulations our approach is
numerically highly efficient at capturing the behaviour of stochastic systems
in terms of the average and higher moments, and we provide expressions for the
computational cost for different system sizes and orders of approximation. {We
show how the moment expansion method can be employed to efficiently {quantify
parameter sensitivity}.} Finally we investigate the effects of using too few
moments on parameter estimation, and provide guidance on how to estimate if the
distribution can be accurately approximated using only a few moments.


title:
Equation of State within Gluon Dominated QGP Model in Relativistic
  Hydrodynamics Approach

abstract:
  The dynamics of Quark-gluon plasma (QGP) as a lump of deconfined free quarks
and gluons is elaborated. Based on the first principal we construct the
Lagrangian that represents the dynamics of QGP. To induce a hydrodynamics
approach, we substitute the gluon fields with flow fields. As a result, the
derived equation of Motion (E.O.M) for gluon dominated QGP shows the form that
similar to Euler equation, and the energy momentum tensor also represents
explicitly the system of ideal fluid. Combining the E.O.M and energy momentum
tensor, the pressure and energy density distribution as the equation of states
are analytically derived.


title: Descent sets for symplectic groups

abstract:
  The descent set of an oscillating (or up-down) tableau is introduced. This
descent set plays the same role in the representation theory of the symplectic
groups as the descent set of a standard tableau plays in the representation
theory of the general linear groups. In particular, we show that the descent
set is preserved by Sundaram's correspondence. This gives a direct
combinatorial interpretation of the branching rules for the defining
representations of the symplectic groups; equivalently, for the Frobenius
character of the action of a symmetric group on an isotypic subspace in a
tensor power of the defining representation of a symplectic group.


title:
Temperature-dependent bulk viscosity of nitrogen gas determined from
  spontaneous Rayleigh-Brillouin scattering

abstract:
  Values for the bulk viscosity of molecular nitrogen gas (N2) were derived
from spontaneous Rayleigh-Brillouin (RB) scattering at ultraviolet wavelengths
(366.8 nm) and at a 90 degree scattering angle. Analysis of the scattering
profiles yield values showing a linear increasing trend in the temperature
interval from 255 K to 340 K. The present values, pertaining to hypersound
acoustics at frequencies in the GHz domain, are found to be in agreement with
results from acoustic attenuation experiments in N2 performed at MHz
frequencies.


title: Pauli spin blockade and the ultrasmall magnetic field effect

abstract:
  Based on the spin-blockade model for organic magnetoresistance we present an
analytic expression for the polaron-bipolaron transition rate, taking into
account the effective nuclear fields on the sites. We reveal the physics
producing qualitatively different magnetoconductance line shapes as well as the
ultrasmall magnetic field effect, and we study the role of the ratio between
the intersite hopping rate and the typical magnitude of the nuclear fields. Our
findings are in agreement with recent experiments and numerical simulations.


title:
Comparison between accretion-related properties of Herbig Ae/Be and T
  Tauri stars

abstract:
  This paper summarizes several results concerning the comparison between
accretion-related properties of cool (T Tauri; T < 7000 K, M < 1 Msun and hot
(Herbig Ae/Be; 7000 < T(K) < 13000; 1 < M(Msun) < 6) pre-main sequence (PMS)
stars. This comparison gives insight into the analogies/differences in the
physics of the star-disk interaction and in the physical mechanisms driving
disk dissipation.
  Several optical and near-IR line luminosities used for low-mass objects are
also valid to estimate typical accretion rates for intermediate-mass stars
under similar empirical expressions. In contrast, the Halpha width at 10% of
peak intensity is used as an accretion tracer for T Tauris, but is not reliable
to estimate accretion rates for Herbig Ae/Bes. This can be explained as a
consequence of the different stellar rotation rates that characterize both
types of stars. In addition, there are similar trends when the accretion rate
is related to the near-IR colours and disk masses, suggesting that viscous
accretion disk models are able to explain these trends for both T Tauri and
Herbig Ae/Be stars. However, there are two major differences between cool and
hot PMS objects. First, the inner gas dissipation timescale, as estimated by
relating the accretion rates and the stellar ages, is slightly faster for
Herbig Ae/Be stars. This could have implications on the physical mechanism able
to form planets around objects more massive than the Sun. Second, the relative
position of Herbig Ae/Bes with disks showing signs of inner dust clearing in
the accretion rate--disk mass plane contrasts with that of transitional T Tauri
stars, when both samples are compared with "classical", non-evolved disks. This
latter difference could be pointing to a different physical mechanism driving
disk evolution, depending on the stellar regime.


title:
Floquet scattering matrix approach to the phase noise of a
  single-electron source in the adiabatic regime

abstract:
  We give the basic elements of the Floquet scattering matrix approach to the
dynamic quantum transport in mesoscopic and nanoscopic conductors. We use the
scattering formalism to discuss the noise power spectrum of a single electron
source working in the adiabatic regime and emitting particles into a chiral
electron waveguide. The noise power is found to be quadratic at low frequencies
and exponentially suppressed at high frequencies.


title:
Overlapping Community Detection in Complex Networks using Symmetric
  Binary Matrix Factorization

abstract:
  Discovering overlapping community structures is a crucial step to
understanding the structure and dynamics of many networks. In this paper we
develop a symmetric binary matrix factorization model (SBMF) to identify
overlapping communities. Our model allows us not only to assign community
memberships explicitly to nodes, but also to distinguish outliers from
overlapping nodes. In addition, we propose a modified partition density to
evaluate the quality of community structures. We use this to determine the most
appropriate number of communities. We evaluate our methods using both synthetic
benchmarks and real world networks, demonstrating the effectiveness of our
approach.


title: Type I Seesaw Mechanism, Lepton Flavour Violation and Higgs Decays

abstract:
  We review and update the current phenomenological constraints on minimal type
I seesaw extensions of the Standard Model in which New Physics content can be
probed at the electroweak scale. In this class of models, the flavour structure
of the neutrino Yukawa couplings is determined by the requirement of
reproducing neutrino oscillation data. The strongest constraints on the seesaw
parameter space are imposed by the very recent upper limit on \mu\ --> e
\gamma\ decay rate. Searches of non-standard Higgs boson decays into a light
and a heavy neutrino may also provide and independent test of these seesaw
scenarios.


title: Model of complex networks based on citation dynamics

abstract:
  Complex networks of real-world systems are believed to be controlled by
common phenomena, producing structures far from regular or random. These
include scale-free degree distributions, small-world structure and assortative
mixing by degree, which are also the properties captured by different random
graph models proposed in the literature. However, many (non-social) real-world
networks are in fact disassortative by degree. Thus, we here propose a simple
evolving model that generates networks with most common properties of
real-world networks including degree disassortativity. Furthermore, the model
has a natural interpretation for citation networks with different practical
applications.


title:
The nonlocal Darboux transformation of the 2D stationary Schr\"odinger
  equation and its relation to the Moutard transformation

abstract:
  The nonlocal Darboux transformation of the two - dimensional stationary
Schr\"odinger equation is considered and its relation to the Moutard
transformation is established. It is shown that a special case of the nonlocal
Darboux transformation provides the Moutard transformation. New examples of
solvable two - dimensional stationary Schr\"odinger operators with smooth
potentials are obtained as an application of the nonlocal Darboux
transformation.


title: Chord distribution along a line in the local Universe

abstract:
  A method is developed to compute the chord length distribution along a line
which intersects a cellular Universe. The cellular Universe is here modeled by
the Poissonian Voronoi Tessellation (PVT) and by a non-Poissonian Voronoi
Tessellation (NPVT). The distribution of the spheres is obtained from common
approximations used in modeling the volumes of Voronoi Diagrams.
  We give analytical formulas for the distributions of the lengths of chords in
both the PVT and NPVT. The astrophysical applications are made to the real Eso
Slice Project and to an artificial slice of galaxies which simulates the 2dF
Galaxy Redshift Survey.


title: Spin-Orbit mediated spin relaxation in monolayer MoS2

abstract:
  We study the intra-valley spin-orbit mediated spin relaxation in monolayers
of MoS2 within a two bands effective Hamiltonian. The intrinsic spin splitting
of the valence band as well as a Rashba-like coupling due to the breaking of
the out-of-plane inversion symmetry are considered. We show that, in the hole
doped regime, the out-of-plane spin relaxation is not very efficient since the
spin splitting of the valence band tends to stabilize the spin polarization in
this direction. We obtain spin lifetimes larger than nanoseconds, in agreement
with recent valley polarization experiments.


title:
Anomalous Raman Spectra and Thickness Dependent Electronic properties of
  WSe2

abstract:
  Typical Raman spectra of transition metal dichalcogenides (TMDs) display two
prominent peaks, E2g and A1g, that are well separated from each other. We find
that these modes are degenerate in bulk WSe2 yielding one single Raman peak. As
the dimensionality is lowered, the observed peak splits in two as a result of
broken degeneracy. In contrast to our experimental findings, our phonon
dispersion calculations reveal that these modes remain degenerate independent
of the number of layers. Interestingly, for minuscule biaxial strain the
degeneracy is preserved but once the crystal symmetry is broken by uniaxial
strain, the degeneracy is lifted. Our calculated phonon dispersion for
uniaxially strained WSe2 shows a perfect match to the measured Raman spectrum
which suggests that uniaxial strain exists in WSe2 flakes possibly induced
during the sample preparation and/or as a result of interaction between WSe2
and the substrate. Furthermore, we find that WSe2 undergoes an indirect to
direct bandgap transition from bulk to monolayers which is ubiquitous for
semiconducting TMDs. These results not only allow us to understand the
vibrational properties of WSe2 but also provides detailed insight to their
physical properties.


title:
Improved Approximation Algorithm for the Number of Queries Necessary to
  Identify a Permutation

abstract:
  In the past three decades, deductive games have become interesting from the
algorithmic point of view. Deductive games are two players zero sum games of
imperfect information. The first player, called "codemaker", chooses a secret
code and the second player, called "codebreaker", tries to break the secret
code by making as few guesses as possible, exploiting information that is given
by the codemaker after each guess. A well known deductive game is the famous
Mastermind game. In this paper, we consider the so called Black-Peg variant of
Mastermind, where the only information concerning a guess is the number of
positions in which the guess coincides with the secret code. More precisely, we
deal with a special version of the Black-Peg game with n holes and k >= n
colors where no repetition of colors is allowed. We present a strategy that
identifies the secret code in O(n log n) queries. Our algorithm improves the
previous result of Ker-I Ko and Shia-Chung Teng (1985) by almost a factor of 2
for the case k = n. To our knowledge there is no previous work dealing with the
case k > n.
  Keywords: Mastermind; combinatorial problems; permutations; algorithms


title: Generalized geometry applied to 4d-supergravity

abstract:
  Generalized complex geometry is an example of a powerful formalism to attempt
the construction of a language adequate to string theory. With the remarkable
property of unifying symplectic and complex manifolds as special cases of a
broader structure it is proving to be the right tool to use when trying to
describe T-duality. The key idea was to look at both geometries as operations
in the direct sum of tangent and cotangent bundle as opposed to the usual
approach, where only the tangent spaces are relevant. In this thesis we will be
interested in developing a formalism drinking from these ideas but for a toy
model of eleven dimensional M-theory: three-form supergravity as introduced by
Ovrut and Waldram.


title: Galactic Ultracompact X-ray Binaries: Disk Stability and Evolution

abstract:
  We study the mass transfer rates and disk stability conditions of
ultracompact X-ray binaries (UCXBs) using empirical time-averaged X-ray
luminosities from Paper I (Cartwright et al. 2013) and compiled information
from the literature. The majority of UCXBs are consistent with evolutionary
tracks for white dwarf donors. Three UCXBs with orbital periods longer than 40
minutes have mass transfer rates above 10^{-10} Msun/year, inconsistent with
white dwarf donor tracks. We show that if helium star donors can retain their
initial high entropy, they can explain the observed mass transfer rates of
these UCXBs. Several UCXBs show persistent luminosities apparently below the
disk instability limit for irradiated He accretion disks. We point out that a
predominantly C and/or O disk (as observed in the optical spectra of several)
lowers the disk instability limit, explaining this disagreement. The orbital
period and low time-averaged mass transfer rate of 2S 0918-549 provide evidence
that the donor star is a low-entropy C/O white dwarf, consistent with optical
spectra. We combine existing information to constrain the masses of the donors
in 4U 1916-053 (0.064+-0.010 Msun) and 4U 1626-67 (<0.036 Msun for a 1.4 Msun
neutron star). We show that 4U 1626-67 is indeed persistent, and not undergoing
a transient outburst, leaving He star models as the best explanation for the
donor.


title: Arithmetic of triangles

abstract:
  The set of segments, each of the next is n times bigger than the first one is
a simple geometric interpretation of the set $\mathbb{N}$ of natural numbers.
In this paper we investigate the opposite situation. We give algebraic
structure to the set of similar triangles with parallel sides. We present
geometric construction of adding of triangles and use it to dissection of
triangles into 15 triangles of different sides.


title: Galactic Ultracompact X-ray Binaries: Empirical Luminosities

abstract:
  Ultracompact X-ray binaries (UCXBs) are thought to have relatively simple
binary evolution post-contact, leading to clear predictions of their luminosity
function. We test these predictions by studying the long-term behavior of known
UCXBs in our Galaxy, principally using data from the MAXI All-Sky Survey and
the Galactic Bulge Scans with RXTE's PCA instrument. Strong luminosity
variations are common (and well-documented) among persistent UCXBs, which
requires an explanation other than the disk instability mechanism. We measure
the luminosity function of known UCXBs in the Milky Way, which extends to lower
luminosities than some proposed theoretical luminosity functions of UCXBs. The
difference between field and globular cluster X-ray luminosity functions in
other galaxies cannot be explained by an increased fraction of UCXBs in
globular clusters. Instead, our measured luminosity function suggests that
UCXBs only make up a small fraction of the X-ray binaries above a few times
10^36 ergs/s in both old field populations and globular clusters.


title:
Similarity based Dynamic Web Data Extraction and Integration System from
  Search Engine Result Pages for Web Content Mining

abstract:
  There is an explosive growth of information in the World Wide Web thus posing
a challenge to Web users to extract essential knowledge from the Web. Search
engines help us to narrow down the search in the form of Search Engine Result
Pages (SERP). Web Content Mining is one of the techniques that help users to
extract useful information from these SERPs. In this paper, we propose two
similarity based mechanisms; WDES, to extract desired SERPs and store them in
the local depository for offline browsing and WDICS, to integrate the requested
contents and enable the user to perform the intended analysis and extract the
desired information. Our experimental results show that WDES and WDICS
outperform DEPTA [1] in terms of Precision and Recall.


title:
Cosmological dynamics of $f(R)$ gravity scalar degree of freedom in
  Einstein frame

abstract:
  $f(R)$ gravity models belong to an important class of modified gravity models
where the late time cosmic accelerated expansion is considered as the
manifestation of the large scale modification of the force of gravity. $f(R)$
gravity models can be expressed in terms of a scalar degree of freedom by
redefinition of models variable. The conformal transformation of the action
from Jordan frame to Einstein frame makes the scalar degree of freedom more
explicit and can be studied conveniently. We have investigated the features of
the scalar degree of freedoms and the consequent cosmological implications of
the power-law ($\xi R^n$) and the Starobinsky (disappearing cosmological
constant) $f(R)$ gravity models numerically in the Einstein frame. Both the
models show interesting behaviour of their scalar degree of freedom and could
produce the accelerated expansion of the Universe in the Einstein frame with
the negative equation of state of the scalar field. However the scalar field
potential for the power-law model is the well behaved function of the field,
whereas the potential becomes flat for higher value of field in the case of the
Starobinsky model. Moreover, the equation of state of the scalar field for the
power-law model is always negative and less than -1/3, which corresponds to the
behaviour of the dark energy that produces the accelerated expansion of the
Universe. This is not always the case for the Starobinsky model. At late times
Starobinsky model behaves as cosmological constant $\Lambda$ as behaves by
power-law model for the values of $n\rightarrow 2$ at all times.


title: A block Hankel generalized confluent Vandermonde matrix

abstract:
  Vandermonde matrices are well known. They have a number of interesting
properties and play a role in (Lagrange) interpolation problems, partial
fraction expansions, and finding solutions to linear ordinary differential
equations, to mention just a few applications. Usually, one takes these
matrices square, $q\times q$ say, in which case the $i$-th column is given by
$u(z_i)$, where we write $u(z)=(1,z,...,z^{q-1})^\top$. If all the $z_i$
($i=1,...,q$) are different, the Vandermonde matrix is non-singular, otherwise
not. The latter case obviously takes place when all $z_i$ are the same, $z$
say, in which case one could speak of a confluent Vandermonde matrix.
Non-singularity is obtained if one considers the matrix $V(z)$ whose $i$-th
column ($i=1,...,q$) is given by the $(i-1)$-th derivative $u^{(i-1)}(z)^\top$.
  We will consider generalizations of the confluent Vandermonde matrix $V(z)$
by considering matrices obtained by using as building blocks the matrices
$M(z)=u(z)w(z)$, with $u(z)$ as above and $w(z)=(1,z,...,z^{r-1})$, together
with its derivatives $M^{(k)}(z)$. Specifically, we will look at matrices whose
$ij$-th block is given by $M^{(i+j)}(z)$, where the indices $i,j$ by convention
have initial value zero. These in general non-square matrices exhibit a
block-Hankel structure. We will answer a number of elementary questions for
this matrix. What is the rank? What is the null-space? Can the latter be
parametrized in a simple way? Does it depend on $z$? What are left or right
inverses? It turns out that answers can be obtained by factorizing the matrix
into a product of other matrix polynomials having a simple structure. The
answers depend on the size of the matrix $M(z)$ and the number of derivatives
$M^{(k)}(z)$ that is involved. The results are obtained by mostly elementary
methods, no specific knowledge of the theory of matrix polynomials is needed.


title:
Ranking journals: Could Google Scholar Metrics be an alternative to
  Journal Citation Reports and Scimago Journal Rank?

abstract:
  The launch of Google Scholar Metrics as a tool for assessing scientific
journals may be serious competition for Thomson Reuters Journal Citation
Reports, and for Scopus powered Scimago Journal Rank. A review of these
bibliometric journal evaluation products is performed. We compare their main
characteristics from different approaches: coverage, indexing policies, search
and visualization, bibliometric indicators, results analysis options, economic
cost and differences in their ranking of journals. Despite its shortcomings,
Google Scholar Metrics is a helpful tool for authors and editors in identifying
core journals. As an increasingly useful tool for ranking scientific journals,
it may also challenge established journals products


title: Yb Valence Change in (Ce,Yb)CoIn5 from spectroscopy and bulk properties

abstract:
  The electronic structure of (Ce,Yb)CoIn5 has been studied by a combination of
photoemission, x-ray absorption and bulk property measurements. Previous
findings of a Ce valence near 3+ for all x and of an Yb valence near 2.3+ for
x>0.3 were confirmed. One new result of this study is that the Yb valence for
x<0.2 increases rapidly with decreasing x from 2.3+ toward 3+, which correlates
well with de Haas van Alphen results showing a change of Fermi surface around
x=0.2. Another new result is the direct observation by angle resolved
photoemission Fermi surface maps of about 50% cross sectional area reductions
of the \alpha- and \beta-sheets for x=1 compared to x=0, and a smaller,
essentially proportionate, size change of the \alpha-sheet for x=0.2. These
changes are found to be in good general agreement with expectations from simple
electron counting. The implications of these results for the unusual robustness
of superconductivity and Kondo coherence with increasing x in this alloy system
are discussed.


title: The projective dimension of profinite modules for pro-p groups

abstract:
  The homology groups introduced by A. Brumer can be used to establish a
criterion ensuring that a profinite $\mathbb{F}_p[[G]]$-module of a pro-$p$
group $G$ has projective dimension $d<\infty$ (cf. Thm. A). This criterion
yields a new characterization of free pro-$p$ groups (cf. Cor. B). Applied to a
semi-direct factor $G\to\mathbb{Z}_p\to G$ isomorphic to $\mathbb{Z}_p$ which
defines a non-trivial end in the sense of A.A. Korenev one concludes that the
closure of the normal closure of the image of $\sigma$ is a free pro-$p$
subgroup (cf. Thm. C). From this result we will deduce a structure theorem (cf.
Thm. D) for finitely generated pro-$p$ groups with infinitely many ends.


title: Quantum field theory on timelike hypersurfaces in Rindler space

abstract:
  The general boundary formulation of quantum field theory is applied to a
massive scalar field in two dimensional Rindler space. The field is quantized
according to both the Schr\"odinger-Feynman quantization prescription and the
holomorphic one in two different spacetime regions: a region bounded by two
Cauchy surfaces and a region bounded by one timelike curve. An isomorphism is
constructed between the Hilbert spaces associated with these two boundaries.
This isomorphism preserves the probabilities that can be extracted from the
free and the interacting quantum field theories, proving the equivalence of the
S-matrices defined in the two settings, when both apply.


title: BIMS: Biomedical Information Management System

abstract:
  In this paper, we present BIMS (Biomedical Information Management System).
BIMS is a software architecture designed to provide a flexible computational
framework to manage the information needs of a wide range of biomedical
research projects. The main goal is to facilitate the clinicians' job in data
entry, and researcher's tasks in data management, in high data quality
biomedical research projects. The BIMS architecture has been designed following
the two-level modeling paradigm, a promising methodology to model rich and
dynamic information environments. In addition, a functional implementation of
BIMS architecture has been developed as a web-based application. The result is
a highly flexible web application which allows modeling and managing large
amounts of heterogeneous biomedical data sets, both textual as well as visual
(medical images) information.


title:
Approximating Continuous Functions with Scattered Translates of the
  Poisson Kernel

abstract:
  The goal of this note is to show that continuous functions may be
approximated using scattered translates of the Poisson kernel.


title: Harmonic motion and Cassini ovals

abstract:
  We consider a two-dimensional free harmonic oscillator where the initial
position is fixed and the initial velocity can change direction. All possible
orbits are ellipses and their enveloping curve is an ellipse too. We show that
the locus of the foci of all elliptical orbits is a Cassini oval. Depending on
the magnitude of the initial velocity we observe all three kinds of Cassini
ovals, one of which is the lemniscate of Bernoulli. These Cassini ovals have
the same foci as the enveloping ellipse.


title:
Flavor-phenomenology of two-Higgs-doublet models with generic Yukawa
  structure

abstract:
  We perform an extensive study of flavor observables in a 2HDM with generic
Yukawa structure (the decoupling limit of the MSSM). We examine the effects in
flavor physics and constrain the model both from tree-level processes and
loop-observables. The free parameters of the model are the heavy Higgs mass,
tan(\beta) and the "non-holomorphic" Yukawa couplings \epsilon^f_ij
(f=u,d,\ell). In our analysis we constrain the elements \epsilon^f_ij in
various ways: In a first step we give order of magnitude constraints on
\epsilon^f_ij from 't Hooft's naturalness criterion. Then we constrain the
Yukawa structure of the type-III 2HDM from tree-level FCNC processes
(B_s,d->\mu^+\mu^-, \tau^-->\mu^-\mu^+\mu^-, etc.) and observe that all flavor
off-diagonal elements except \epsilon^u_32,31 and \epsilon^u_23,13 must be very
small in order to satisfy the experimental bounds. In a third step, we consider
Higgs mediated loop contributions to FCNC processes (b->s,d\gamma,
\mu->e\gamma, etc.) finding that also \epsilon^u_13 and \epsilon^u_23 must be
very small, while the bounds on \epsilon^u_31 and \epsilon^u_32 are especially
weak. Taking into account the constraints from FCNC processes we study the
possible size of contributions from tree-level charged Higgs exchange.
Interestingly, the unconstrained elements \epsilon^u_{32,31} enter directly the
branching ratios for B->\tau\nu, B->D\tau\nu and B->D*\tau\nu and we show that
the deviations from the SM predictions in these processes can be explained
simultaneously. We give upper limits on the branching ratios of the lepton
flavor-violating neutral B meson decays and correlate the radiative lepton
decays to the corresponding neutral current lepton decays (\tau^-
->\mu^-\mu^+\mu^-, \tau^- ->e^-\mu^+\mu^- and \mu^- ->e^-e^+e^-). A detailed
appendix contains all relevant information for the considered processes for
general scalar-fermion-fermion couplings.


title:
Algorithms for estimating spectral density functions for periodic
  potentials on the half line

abstract:
  For Hill's equation on [0,infinity) we prove new characterizations of the
spectral function rho(lambda) and the spectral density function f(lambda) based
on analysis involving a companion system of first order differential equations
in [6,7]. A numerical algorithm is derived and implemented based on coefficient
approximation. Results for several examples, including the Mathieu equation,
are presented.


title:
Semi-derived Hall algebras and tilting invariance of Bridgeland-Hall
  algebras

abstract:
  Inspired by recent work of Bridgeland, from the category C^b(E) of bounded
complexes over an exact category E satisfying certain finiteness conditions, we
construct an associative unital "semi-derived Hall algebra" SDH(E). This
algebra is an object sitting, in some sense, between the usual Hall algebra
H(C^b(E)) and the Hall algebra of the bounded derived category D^b(E),
introduced by Toen and further generalized by Xiao and Xu. It has the structure
of a free module over a suitably defined quantum torus of acyclic complexes,
with a basis given by the isomorphism classes of objects in the bounded derived
category D^b(E). We prove the invariance of SDH(E) under derived equivalences
induced by exact functors between exact categories.
  For E having enough projectives and such that each object has a finite
projective resolution, we describe a similar construction for the category of
Z/2-graded complexes, with similar properties of associativity, freeness over
the quantum torus and derived invariance. In particular, we obtain that this
Z/2-graded semi-derived Hall algebra is isomorphic to the two-periodic Hall
algebra recently introduced by Bridgeland. We deduce that Bridgeland's Hall
algebra is preserved under tilting.
  When E is hereditary and has enough projectives, we show that the
multiplication in SDH(E) is given by the same formula as the Ringel-Hall
multiplication, and SDH(E) is isomorphic to a certain quotient of the classical
Hall algebra H(C^b(E)) localized at the classes of acyclic complexes. We also
prove the same result in the Z/2-graded case.


title:
J/Psi Elliptic Flow in Pb-Pb Collisions at $\sqrt{s_{\rm NN}}$ = 2.76
  TeV

abstract:
  We report on the first measurement of inclusive J/$\psi$ elliptic flow,
$v_2$, in heavy-ion collisions at the LHC. The measurement is performed with
the ALICE detector in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV in the
rapidity range $2.5 < y < 4.0$. The dependence of the J/$\psi$ $v_2$ on the
collision centrality and on the J/$\psi$ transverse momentum is studied in the
range $0 < p_{\rm T} < 10$ GeV/$c$. For semi-central Pb-Pb collisions at
$\sqrt{s_{\rm NN}} = 2.76$ TeV, an indication of non-zero $v_2$ is observed
with a maximum value of $v_2 = 0.116 \pm 0.046 {\rm (stat.)} \pm 0.029 {\rm
(syst.)}$ for J/$\psi$ in the transverse momentum range $2 < p_{\rm T} < 4$
GeV/$c$. The elliptic flow measurement complements the previously reported
ALICE results on the inclusive J/$\psi$ nuclear modification factor and favors
the scenario of a significant fraction of J/$\psi$ production from charm quarks
in a deconfined partonic phase.


title: Naturally graded Zinbiel algebras with nilindex $n-3$

abstract:
  We present the classification of a subclass of $n$-dimensional naturally
graded Zinbiel algebras. This subclass has the nilindex $n-3$ and the
characteristic sequence $(n-3,2,1).$ In fact, this result completes the
classification of naturally graded Zinbiel algebras of nilindex $n-3.$


title: Feedback models and stability analysis of three economic paradigms

abstract:
  In this paper, simple mathematical models from Control Theory are applied to
three very important economic paradigms, namely (a) minimum wages in
self-regulating markets, (b) market-versus-true values and currency rates, and
(c) government spending and taxation levels. Analytical solutions are provided
in all three paradigms and some useful conclusions are drawn in terms of
variable analysis. This short study can be used as an example of how feedback
models and stability analysis can be applied as a guideline of 'proofs' in the
context of economic policies.


title:
Single-Particle Momentum Distributions of Efimov States in Mixed-Species
  Systems

abstract:
  We solve the three-body bound state problem in three dimensions for mass
imbalanced systems of two identical bosons and a third particle in the
universal limit where the interactions are assumed to be of zero-range. The
system displays the Efimov effect and we use the momentum-space wave equation
to derive formulas for the scaling factor of the Efimov spectrum for any mass
ratio assuming either that two or three of the two-body subsystems have a bound
state at zero energy. We consider the single-particle momentum distribution
analytically and numerically and analyse the tail of the momentum distribution
to obtain the three-body contact parameter. Our finding demonstrate that the
functional form of the three-body contact term depends on the mass ratio and we
obtain an analytic expression for this behavior. To exemplify our results, we
consider mixtures of Lithium with either two Caesium or Rubium atoms which are
systems of current experimental interest.

categories: cond-mat.quant-gas math-ph math.MP nucl-th quant-ph


title:
An optimal lower curvature bound for convex hypersurfaces in Riemannian
  manifolds

abstract:
  It is proved that a convex hypersurface in a Riemannian manifold of sectional
curvature at least k is an Alexandrov's space of curvature at least k. This
theorem provides an optimal lower curvature bound for an older theorem of
Buyalo.


title: Bounds on the diameters of $r$-stacked and $k$-neighborly polytopes

abstract:
  We improve Larman's bound on the diameter of a polytope by showing that if
$\Delta$ is a normal simplicial complex, all of whose missing faces have size
at most $r$, then the diameter of the facet-ridge graph of $\Delta$ is not
larger than $2^{r-2}n$, where $n$ is the number of vertices of $\Delta$. We
then use this result to provide new upper bounds on the diameters of the
facet-ridge graphs of $k$-neighborly spheres, $r$-stacked spheres, and
polytopes with small $g_r$. Specifically, our bounds imply that $r$-stacked
spheres with $r=O(\log n)$ satisfy the polynomial Hirsch conjecture.


title: Nonlinear imaging and 3D-mapping of terahertz fields with Kerr media

abstract:
  We investigate the spatially and temporally resolved four-wave mixing of
terahertz fields and optical pulses in large band-gap dielectrics, such as
diamond. We show that it is possible to perform beam profiling and space-time
resolved mapping of terahertz fields with sub-wavelength THz resolution by
encoding the spatial information into an optical signal, which can then be
recorded by a standard CCD camera.


title:
A Behavioural Foundation for Natural Computing and a Programmability
  Test

abstract:
  What does it mean to claim that a physical or natural system computes? One
answer, endorsed here, is that computing is about programming a system to
behave in different ways. This paper offers an account of what it means for a
physical system to compute based on this notion. It proposes a behavioural
characterisation of computing in terms of a measure of programmability, which
reflects a system's ability to react to external stimuli. The proposed measure
of programmability is useful for classifying computers in terms of the apparent
algorithmic complexity of their evolution in time. I make some specific
proposals in this connection and discuss this approach in the context of other
behavioural approaches, notably Turing's test of machine intelligence. I also
anticipate possible objections and consider the applicability of these
proposals to the task of relating abstract computation to nature-like
computation.


title:
Dissipative versus Conditional Generation of Gaussian Entanglement and
  Spin Squeezing

abstract:
  Spin squeezing of collective atomic spins can be achieved conditionally via
probing with light and subsequent homodyne detection, as is done in a Quantum
Nondemolition measurement. Recently it has been shown that squeezing can also
be created unconditionally by a properly designed dissipative dynamics. We
compare the two approaches in a Gaussian description, and optimize over all
Gaussian light-matter interactions. We find that in the optimal unconditional
scheme based on dissipation the level of squeezing scales as $d^{-1/2}$. In
contrast, the optimal conditional scheme based on measurement of light -- which
in fact is not a Quantum Nondemolition measurement -- can provide squeezing
which scales as $d^{-1}$ in the most relevant regime of moderate optical
depths. Our results apply directly also to the creation of entanglement in the
form of non-local spin squeezing of two atomic ensembles.


title:
A Graph Theoretic Approach to Utilizing Protein Structure to Identify
  Non-Random Somatic Mutations

abstract:
  Background: It is well known that the development of cancer is caused by the
accumulation of somatic mutations within the genome. For oncogenes
specifically, current research suggests that there is a small set of "driver"
mutations that are primarily responsible for tumorigenesis. Further, due to
some recent pharmacological successes in treating these driver mutations and
their resulting tumors, a variety of methods have been developed to identify
potential driver mutations using methods such as machine learning and
mutational clustering. We propose a novel methodology that increases our power
to identify mutational clusters by taking into account protein tertiary
structure via a graph theoretical approach.
  Results: We have designed and implemented GraphPAC (Graph Protein Amino Acid
Clustering) to identify mutational clustering while considering protein spatial
structure. Using GraphPAC, we are able to detect novel clusters in proteins
that are known to exhibit mutation clustering as well as identify clusters in
proteins without evidence of prior clustering based on current methods.
Specifically, by utilizing the spatial information available in the Protein
Data Bank (PDB) along with the mutational data in the Catalogue of Somatic
Mutations in Cancer (COSMIC), GraphPAC identifies new mutational clusters in
well known oncogenes such as EGFR and KRAS. Further, by utilizing graph theory
to account for the tertiary structure, GraphPAC identifies clusters in DPP4,
NRP1 and other proteins not identified by existing methods. The R package is
available at: http://bioconductor.org/packages/release/bioc/html/GraphPAC.html
  Conclusion: GraphPAC provides an alternative to iPAC and an extension to
current methodology when identifying potential activating driver mutations by
utilizing a graph theoretic approach when considering protein tertiary
structure.


title:
Transmission and reflection of strongly nonlinear solitary waves at
  granular interfaces

abstract:
  The interaction of a solitary wave front with an interface formed by two
strongly-nonlinear non-cohesive granular lattices displays rich behaviour,
characterized by the breakdown of continuum equations of motion in the vicinity
of the interface. By treating the solitary wave as a quasiparticle with an
effective mass, we construct an intuitive (energy and linear momentum
conserving) discrete model to predict the amplitudes of the transmitted
solitary waves generated when an incident solitary wave front, parallel to the
interface, moves from a denser to a lighter granular hexagonal lattice. Our
findings are corroborated with simulations. We then successfully extend this
model to oblique interfaces, where we find that the angle of refraction and
reflection of a solitary wave follows, below a critical value, an analogue of
Snell's law in which the solitary wave speed replaces the speed of sound, which
is zero in the sonic vacuum.


title: Fault Tolerance in Distributed Systems using Fused State Machines

abstract:
  Replication is a standard technique for fault tolerance in distributed
systems modeled as deterministic finite state machines (DFSMs or machines). To
correct f crash or f/2 Byzantine faults among n different machines, replication
requires nf additional backup machines. We present a solution called fusion
that requires just f additional backup machines. First, we build a framework
for fault tolerance in DFSMs based on the notion of Hamming distances. We
introduce the concept of an (f,m)-fusion, which is a set of m backup machines
that can correct f crash faults or f/2 Byzantine faults among a given set of
machines. Second, we present an algorithm to generate an (f,f)-fusion for a
given set of machines. We ensure that our backups are efficient in terms of the
size of their state and event sets. Our evaluation of fusion on the widely used
MCNC'91 benchmarks for DFSMs show that the average state space savings in
fusion (over replication) is 38% (range 0-99%). To demonstrate the practical
use of fusion, we describe its potential application to the MapReduce
framework. Using a simple case study, we compare replication and fusion as
applied to this framework. While a pure replication-based solution requires 1.8
million map tasks, our fusion-based solution requires only 1.4 million map
tasks with minimal overhead during normal operation or recovery. Hence, fusion
results in considerable savings in state space and other resources such as the
power needed to run the backup tasks.


title:
A classical simulation of nonlinear Jaynes--Cummings and Rabi models in
  photonic lattices

abstract:
  The interaction of a two-level atom with a single-mode quantized field is one
of the simplest models in quantum optics. Under the rotating wave
approximation, it is known as the Jaynes-Cummings model and without it as the
Rabi model. Real-world realizations of the Jaynes-Cummings model include
cavity, ion trap and circuit quantum electrodynamics. The Rabi model can be
realized in circuit quantum electrodynamics. As soon as nonlinear couplings are
introduced, feasible experimental realizations in quantum systems are
drastically reduced. We propose a set of two photonic lattices that classically
simulates the interaction of a single two-level system with a quantized field
under field nonlinearities and nonlinear couplings as long as the quantum
optics model conserves parity. We describe how to reconstruct the mean value of
quantum optics measurements, such as photon number and atomic energy
excitation, from the intensity and from the field, such as von Neumann entropy
and fidelity, at the output of the photonic lattices. We discuss how typical
initial states involving coherent or displaced Fock fields can be engineered
from recently discussed Glauber-Fock lattices. As an example, the Buck-Sukumar
model, where the coupling depends on the intensity of the field, is classically
simulated for separable and entangled initial states.


title:
Stability of the massive graviton around a BTZ black hole in three
  dimensions

abstract:
  We investigate the massive graviton stability of the BTZ black hole obtained
from three dimensional massive gravities which are classified into the
parity-even and parity-odd gravity theories. In the parity-even gravity theory,
we perform the $s$-mode stability analysis by using the BTZ black string
perturbations, which gives two Schr\"odinger equations with frequency-dependent
potentials. The $s$-mode stability is consistent with the generalized
Breitenlohner-Freedman bound for spin-2 field. It seems that for the parity-odd
massive gravity theory, the BTZ black hole is stable when the imaginary part of
quasinormal frequencies of massive graviton is positive. However, this
condition is not consistent with the $s$-mode stability based on the
second-order equation obtained after squaring the first-order equation. Finally
we explore the black hole stability connection between the parity-odd and
parity-even massive gravity theories.


title: A bright impulsive solar burst detected at 30 THz

abstract:
  Ground- and space-based observations of solar flares from radio wavelengths
to gamma-rays have produced considerable insights but raised several unsolved
controversies. The last unexplored wavelength frontier for solar flares is in
the range of submillimeter and infrared wavelengths. Here we report the
detection of an intense impulsive burst at 30 THz using a new imaging system.
The 30 THz emission exhibited remarkable time coincidence with peaks observed
at microwave, mm/submm, visible, EUV and hard X-ray wavelengths. The emission
location coincides with a very weak white-light feature, and is consistent with
heating below the temperature minimum in the atmosphere. However, there are
problems in attributing the heating to accelerated electrons. The peak 30 THz
flux is several times larger than the usual microwave peak near 9 GHz,
attributed to non-thermal electrons in the corona. The 30 THz emission could be
consistent with an optically thick spectrum increasing from low to high
frequencies. It might be part of the same spectral component found at sub-THz
frequencies whose nature remains mysterious. Further observations at these
wavelengths will provide a new window for flare studies.


title: Keck II Observations of Hemispherical Differences in H2O2 on Europa

abstract:
  We present results from Keck II observations of Europa over four consecutive
nights using the near-infrared spectrograph (NIRSPEC). Spectra were collected
in the 3.14--4.0 micron range, allowing detection and monitoring of the 3.5
micron feature due to hydrogen peroxide. Galileo Near-Infrared Spectrometer
(NIMS) results first revealed hydrogen peroxide on Europa in the anti-jovian
region of the leading hemisphere at an abundance of 0.13+/-0.07% by number
abundance relative to water. We find comparable results for the two nights over
which we observed the leading hemisphere. Significantly, we observed a small
amount of hydrogen peroxide (~0.04%) during observations of Europa's anti- and
sub-Jovian hemispheres. Almost no hydrogen peroxide was detected during
observations of just the trailing hemisphere. We conclude that the Galileo
observations likely represent the maximum hydrogen peroxide concentration, the
exception potentially being the cold water ice regions of the poles, which are
not readily observable from the ground. Our mapping of the peroxide abundance
across Europa requires revisions to previous estimates for Europa's global
surface abundance of oxidants and leads to a reduction in the total oxidant
delivery expected for the sub-surface ocean, if exchange of surface material
with the ocean occurs.


title: Defects on cylinders: superfluid helium films and bacterial cell walls

abstract:
  There is a deep analogy between the physics of crystalline solids and the
behavior of superfluids, dating back to pioneering work of Phillip Anderson,
Paul Martin and others. The stiffness to shear deformations in a periodic
crystal resembles the superfluid density that controls the behavior of
supercurrents in neutral superfluids such as He^4. Dislocations in solids have
a close analogy with quantized vortices in superfluids. Remarkable recent
experiments on the way rod-shaped bacteria elongate their cell walls have
focused attention on the dynamics and interactions of point-like dislocation
defects in partially ordered cylindrical crystalline monolayers. In these
lectures, we review the physics of superfluid helium films on cylinders and
discuss how confinement in one direction affects vortex interactions with
supercurrents. Although there are similarities with the way dislocations
respond to strains on cylinders, important differences emerge, due to the
vector nature of the topological charges characterizing the dislocations.


title: Scale invariance and the electroweak symmetry breaking

abstract:
  We argue that classical scale invariance provides a technically natural
solution to the problem of the radiative stability of the electroweak scale.
Some realistic electroweak scale-invariant models are considered and their
possible manifestations at the LHC are briefly discussed.


title: Modeling vitreous silica bilayers

abstract:
  We computer model a free-standing vitreous silica bilayer which has recently
been synthesized and characterized experimentally in landmark work. Here we
model the bilayer using a computer assembly procedure that starts from a single
layer of amorphous graphene, generated using a bond switching algorithm from an
initially crystalline graphene structure. Next each bond is decorated with an
oxygen atom and the carbon atoms are relabeled as silicon. This monolayer can
be now thought of as a two dimensional network of corner sharing triangles.
Next each triangle is made into a tetrahedron, by raising the silicon atom
above each triangle and adding an additional singly coordinated oxygen atom at
the apex. The final step is to mirror reflect this layer to form a second layer
and then attach the two layers together to form the bilayer.
  We show that this vitreous silica bilayer has the additional macroscopic
degrees of freedom to easily form a network of identical corner sharing
tetrahedra if there is a symmetry plane through the center of the bilayer going
through the layer of oxygen ions that join the upper and lower layers. This has
the consequence that the upper rings lie exactly above the lower rings, which
are tilted in general. The assumption of a network of perfect corner sharing
tetrahedra leads to a range of possible densities that we have previously
characterized in three dimensional zeolites as a flexibility window. Finally,
using a realistic potential, we have relaxed the bilayer to determine the
density, and other structural characteristics such as the Si-Si pair
distribution functions and the Si-O-Si bond angle distribution, which are
compared to the experimental results obtained by direct imaging.


title: Distribution of the time to explosion for one-dimensional diffusions

abstract:
  We study the distribution of the time to explosion for one-dimensional
diffusions. We relate this question to computing the expectations of suitable
nonnegative local martingales, and to the distributions of related diffusions
with unit variance. Moreover, we characterize the distribution function of the
time to explosion as the minimal solution to a certain Cauchy problem for an
appropriate parabolic differential equation; this leads to alternative
characterizations of Feller's criterion for explosions. We discuss in detail
several examples for which it is possible to obtain analytic expressions for
the corresponding distribution of the time to explosion, using the
methodologies developed in the paper.


title:
Measurement of the Y(1S), Y(2S), and Y(3S) cross sections in pp
  collisions at sqrt(s) = 7 TeV

abstract:
  The Upsilon(1S), Upsilon(2S), and Upsilon(3S) production cross sections are
measured using a data sample corresponding to an integrated luminosity of 35.8
+/-1.4 inverse picobarns of proton-proton collisions at sqrt(s) = 7 TeV,
collected with the CMS detector at the LHC. The Upsilon resonances are
identified through their decays to dimuons. Integrated over the Upsilon
transverse momentum range pt[Upsilon] < 50 GeV and rapidity range
abs(y[Upsilon]) < 2.4, and assuming unpolarized Upsilon production, the
products of the Upsilon production cross sections and dimuon branching
fractions are sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = (8.55 +/-
0.05 +0.56/-0.50 +/- 0.34) nb, sigma(pp to Upsilon(2S) X) B(Upsilon(2S) to mu+
mu-) = (2.21 +/- 0.03 +0.16/-0.14 +/- 0.09) nb, sigma(pp to Upsilon(3S) X)
B(Upsilon(3S) to mu+ mu-) = (1.11 +/- 0.02 +0.10/-0.08 +/- 0.04) nb, where the
first uncertainty is statistical, the second is systematic, and the third is
from the uncertainty in the integrated luminosity. The differential cross
sections in bins of transverse momentum and rapidity, and the cross section
ratios are presented. Cross section measurements performed within a restricted
muon kinematic range and not corrected for acceptance are also provided. These
latter measurements are independent of Upsilon polarization assumptions. The
results are compared to theoretical predictions and previous measurements.


title:
Electric Field Effects on the Optical Vibrations in AB-Stacked Bilayer
  Graphene

abstract:
  Using first-principles methods, we show that an applied perpendicular
electric field $E$ breaks the inversion symmetry of AB-stacked bilayer graphene
(BLG), thereby slightly mixing the two in-plane high-energy optical vibrations
($E_g$ and $E_u$ modes). The mixed amplitudes increase parabolically with
respect to the field strength when $E$$<$2.0 V/nm, and then exhibit linear
dependence when $E$$>$2.0 V/nm. In contrast, the mixing effect on the
out-of-plane vibrations ($A_{1g}$ and $A_{2u}$ modes) is found to be much
stronger, with the mixed amplitudes nearly an order of magnitude larger than
those for the in-plane modes. For the two in-plane modes, we then calculate
their phonon linewidths and frequency shifts as a function of the electric
field as well as the Fermi level. Our results reveal delicate interplay between
electrons and phonons in BLG, tunable by the applied fields and charge carrier
densities.