60 research outputs found
Homogenized dynamics of stochastic partial differential equations with dynamical boundary conditions
A microscopic heterogeneous system under random influence is considered. The
randomness enters the system at physical boundary of small scale obstacles as
well as at the interior of the physical medium. This system is modeled by a
stochastic partial differential equation defined on a domain perforated with
small holes (obstacles or heterogeneities), together with random dynamical
boundary conditions on the boundaries of these small holes.
A homogenized macroscopic model for this microscopic heterogeneous stochastic
system is derived. This homogenized effective model is a new stochastic partial
differential equation defined on a unified domain without small holes, with
static boundary condition only. In fact, the random dynamical boundary
conditions are homogenized out, but the impact of random forces on the small
holes' boundaries is quantified as an extra stochastic term in the homogenized
stochastic partial differential equation. Moreover, the validity of the
homogenized model is justified by showing that the solutions of the microscopic
model converge to those of the effective macroscopic model in probability
distribution, as the size of small holes diminishes to zero.Comment: Communications in Mathematical Physics, to appear, 200
The time-transgressive initiation of boreal ice-caps: continental and oceanic evidence reconciled
International audienc
Oxygen and carbon isotopic composition and biogeographic distribution of planktonic foraminifera in the Indian Ocean
International audienc
Variations in mode of formation and temperature of oceanic deep waters over the past 125,000 years
International audienc
TARANIS — Scientific payload and mission strategy
International audienceOn December 2010 the implementation phase of the TARANIS micro-satellite was authorized by the French space agency. TARANIS is dedicated to the study of impulsive transfers of energy between the Earth atmosphere and the space environment, and more precisely to the physics of the Transient Luminous Events (TLEs) and of the Terrestrial Gamma ray Flashes (TGFs). By 2015 TARANIS will provide combined Nadir observations of TLEs and TGFs, high resolution measurements of energetic electrons, and wave field measurements. The strategy adopted to maximize the scientific return of the data is presented
Paleoclimatologie isotopique et histoire de l'eau profonde Atlantique depuis 15 millions d'annees
SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Measurement of J/Ψ production in pp collisions at √s=7 TeV
The production of J/psi mesons in proton-proton collisions at root s = 7 TeV is studied with the LHCb detector at the LHC. The differential cross-section for prompt J/psi production is measured as a function of the J/psi transverse momentum p(T) and rapidity y in the fiducial region p(T) is an element of [0; 14] GeV/c and y is an element of [2.0; 4.5]. The differential cross-section and fraction of J/psi from b-hadron decays are also measured in the same p(T) and y ranges. The analysis is based on a data sample corresponding to an integrated luminosity of 5.2 pb(-1). The measured cross-sections integrated over the fiducial region are 10.52 +/- 0.04 +/- 1.40(-2.20)(+1.64) mu b for prompt J/psi production and 1.14 +/- 0.01 +/- 0.16 mu b for J/psi from b-hadron decays, where the first uncertainty is statistical and the second systematic. The prompt J/psi production cross-section is obtained assuming no J/psi polarisation and the third error indicates the acceptance uncertainty due to this assumption
- …