Hypercontractivity on the qq-Araki-Woods algebras

Extending a work of Carlen and Lieb, Biane has obtained the optimal hypercontractivity of the $q$-Ornstein-Uhlenbeck semigroup on the $q$-deformation of the free group algebra. In this note, we look for an extension of this result to the type III situation, that is for the $q$-Araki-Woods algebras. We show that hypercontractivity from $L^p$ to $L^2$ can occur if and only if the generator of the deformation is bounded.Comment: 17 page

SAXO+ upgrade : second stage AO system end-to-end numerical simulations

SAXO+ is a proposed upgrade to SAXO, the AO system of the SPHERE instrument on the ESO Very Large Telescope. It will improve the capabilities of the instrument for the detection and characterization of young giant planets. It includes a second stage adaptive optics system composed of a dedicated near-infrared wavefront sensor and a deformable mirror. This second stage will remove the residual wavefront errors left by the current primary AO loop (SAXO). This paper focuses on the numerical simulations of the second stage (SAXO+) and concludes on the impact of the main AO parameters used to build the design strategy. Using an end-to-end AO simulation tool (COMPASS), we investigate the impact of several parameters on the performance of the AO system. We measure the performance in minimizing the star residuals in the coronagraphic image. The parameters that we study are : the second stage frequency, the photon flux on each WFS, the first stage gain and the DM number of actuators of the second stage. We show that the performance is improved by a factor 10 with respect to the current AO system (SAXO). The optimal second stage frequency is between 1 and 2 kHz under good observing conditions. In a red star case, the best SAXO+ performance is achieved with a low first stage gain of 0.05, which reduces the first stage rejection.Comment: 10 pages, 8 figures. Submitted to AO4ELT7 conference proceeding

L'Hypercholestérolémie familiale (caractéristiques et prise en charge)

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Les Glycogénoses d'expression musculaire (Á propos de deux cas de maladie de McArdle)

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Intérêt de l'épreuve d'effort et de l'analyse de la respiration mitochondriale dans l'exploration des intolérances musculaires à l'effort

MONTPELLIER-BU Médecine UPM (341722108) / SudocPARIS-BIUM (751062103) / SudocMONTPELLIER-BU Médecine (341722104) / SudocSudocFranceF

Le risque cardiovasculaire

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

La carnitine en néonatalogie (revue bibliographique et mise en place d'un protocole de supplémentation chez le nouveau-né prématuré)

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Le diabète de type 1 (Traitements actuels et futurs. Evaluation de l'amélioration apportée par les nouveaux modes d'administration de l'insuline)

MONTPELLIER-BU Pharmacie (341722105) / SudocSudocFranceF

Implications des transporteurs du lactate dans les altérations du métabolisme lactique dans les états d'insulinorésistance (effets de l'activité physique et de la perte de poids)

MONTPELLIER-BU Médecine UPM (341722108) / SudocPARIS-BIUP (751062107) / SudocMONTPELLIER-BU Médecine (341722104) / SudocSudocFranceF