Jeans' gravitational instability and nonextensive kinetic theory
Departamento de Física, UFRN, C.P. 1641, 59072-970 Natal, RN, Brazil
Corresponding author: J. A. S. Lima, email@example.com
Accepted: 27 August 2002
The concept of Jeans gravitational instability is rediscussed in the framework of nonextensive statistics and its associated kinetic theory. A simple analytical formula generalizing the Jeans criterion is derived by assuming that the unperturbed self-gravitating collisionless gas is kinetically described by the q-parameterized class of power law velocity distributions. It is found that the critical values of wavelength and mass depend explicitly on the nonextensive q-parameter. The standard Jeans wavelength derived for a Maxwellian distribution is recovered in the limiting case . For power-law distributions with cutoff, the instability condition is weakened with the system becoming unstable even for wavelengths of the disturbance smaller than the standard Jeans length .
Key words: gravitation / hydrodynamics
© ESO, 2002