%0 Journal Article %T Self-gravity, Resonances, and Orbital Diffusion in Stellar Disks %+ Institut d'Astrophysique de Paris (IAP) %+ Université Pierre et Marie Curie - Paris 6 (UPMC) %A Fouvry, Jean-Baptiste %A Binney, James %A Pichon, Christophe %< avec comité de lecture %@ 0004-637X %J The Astrophysical Journal %I American Astronomical Society %V 806 %8 2015 %D 2015 %Z 1504.04834 %Z 2015ApJ...806..117F %R 10.1088/0004-637X/806/1/117 %K diffusion %K galaxies: evolution %K galaxies: kinematics and dynamics %K galaxies: spiral %K gravitation %K Astrophysics - Astrophysics of Galaxies %Z Sciences of the Universe [physics]Journal articles %X Fluctuations in a stellar system's gravitational field cause the orbits of stars to evolve. The resulting evolution of the system can be computed with the orbit-averaged Fokker-Planck equation once the diffusion tensor is known. We present the formalism that enables one to compute the diffusion tensor from a given source of noise in the gravitational field when the system's dynamical response to that noise is included. In the case of a cool stellar disk we are able to reduce the computation of the diffusion tensor to a one-dimensional integral. We implement this formula for a tapered Mestel disk that is exposed to shot noise and find that we are able to explain analytically the principal features of a numerical simulation of such a disk. In particular the formation of narrow ridges of enhanced density in action space is recovered. As the disk's value of Toomre's Q is reduced and the disk becomes more responsive, there is a transition from a regime of heating in the inner regions of the disk through the inner Lindblad resonance to one of radial migration of near-circular orbits via the corotation resonance in the intermediate regions of the disk. The formalism developed here provides the ideal framework in which to study the long-term evolution of all kinds of stellar disks. %G English %L insu-03644938 %U https://insu.hal.science/insu-03644938 %~ INSU %~ UPMC %~ CNRS %~ IAP %~ UPMC_POLE_2 %~ SORBONNE-UNIVERSITE %~ SU-INF-2018 %~ SU-SCIENCES %~ SU-TI %~ ALLIANCE-SU