Artículos de revistas
Explaining a changeover from normal to super diffusion in time-dependent billiards
Fecha
2018-03-01Registro en:
EPL, v. 121, n. 6, 2018.
1286-4854
0295-5075
10.1209/0295-5075/121/60003
2-s2.0-85047362401
2-s2.0-85047362401.pdf
Autor
Universidade de Saõ Paulo
Universidade Federal do Paraná (UFPR)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
The changeover from normal to super diffusion in time-dependent billiards is explained analytically. The unlimited energy growth for an ensemble of bouncing particles in time-dependent billiards is obtained by means of a two-dimensional mapping of the first and second moments of the speed distribution function. We prove that, for low initial speeds the average speed of the ensemble grows with exponent of the number of collisions with the boundary, therefore exhibiting normal diffusion. Eventually, this regime changes to a faster growth characterized by an exponent corresponding to super diffusion. For larger initial energies, the temporary symmetry in the diffusion of speeds explains an initial plateau of the average speed.