Title: Soluble model of Bose-atoms with two level internal structure: non-conventional Bose-Einstein condensation
Author(s):

	M. Corgini (Departamento de Matemáticas, Universidad de La Serena, Cisternas 1200, La Serena, Chile; Laboratorio de Análisis Estocástico, Chile) ,
	D.P. Sankovich (Steklov Mathematical Institute, Gubkin Str. 8, 119991, Moscow, Russia)

For a Bose atom system whose energy operator is diagonal in the so-called number operators and its ground state has an internal two-level structure with negative energies, exact expressions for the limit free canonical energy and pressure are obtained. The existence of non-conventional Bose-Einstein condensation has been also proved.

Key words: approximating Hamiltonian method, non-conventional Bose-Einstein condensation
PACS: 05.30.Jp, 67.85.Jk