2005/12/01 by L. Zhang, R. V. E. Lovelace
Physics and Astronomy · #Accretion (finance) #Angular momentum #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Classical mechanics #Galaxies: Formation, Evolution, Phenomena #Hamiltonian (control theory) #Kinetic energy #Physics #Quantum electrodynamics #Total angular momentum quantum number #astro-ph
paper · pdf · doi:10.1007/s10509-005-8792-2
published as Astrophys.Space Sci. 300 (2005) 395 · 24 pages, 8 figures
openalex publication_date 2005/12/01 · arxiv created 2006/10/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
This work derives the linearized equations of motion, the Lagrangian density, the Hamiltonian density, and the canonical angular momentum density for general perturbations [∝ exp(imϕ) with m=0,± 1,..] of a geometrically thin self-gravitating, homentropic fluid disk including the pressure. The theory is applied to ``eccentric,'' m=± 1 perturbations of a geometrically thin Keplerian disk. We find m=1 modes at low frequencies relative to the Keplerian frequency. Further, it shown that these modes can have negative energy and negative angular momentum. The radial propagation of these low frequency m=1 modes can transport angular momentum away from the inner region of a disk and thus increase the rate of mass accretion. Depending on the radial boundary conditions there can be discrete low-frequency, negative-energy, m=1 modes.