  We numerically study a Bose-Hubbard ring of finite size with disorder
containing a finite number of bosons that are subject to an on-site two-body
interaction. Our results show that moderate interactions induce dynamical
thermalization in this isolated system. In this regime the individual many-body
eigenstates are well described by the standard thermal Bose-Einstein
distribution for well-defined values of the temperature and the chemical
potential which depend on the eigenstate under consideration. We show that the
dynamical thermalization conjecture works well both at positive and negative
temperatures. The relations to quantum chaos, quantum ergodicity and to the
Aberg criterion are also discussed.
