bethe approximation;
density of states;
non-interacting many-body systems;
combinatorics;
QUANTUM;
THERMALIZATION;
D O I:
10.1088/1751-8121/adae68
中图分类号:
O4 [物理学];
学科分类号:
0702 ;
摘要:
We use a combinatorial approach to obtain exact expressions for the many-body density of states of fermionic and bosonic gases with equally spaced single-particle spectra. We identify a mapping that reveals a remarkable property, namely, fermionic and bosonic gases have the same many-body density of states, up to a shift corresponding to ground state energy. Additionally, we show that there is a regime, comprising the validity range of the Bethe approximation, where the many-body density of states becomes independent of the number of particles.