The electron correlations in narrow energy bands are examined within the framework of the Hubbard model. The single-particle Green function and energy spectrum are obtained in a paramagnetic state at half-filling by means ...

In the present paper we investigate a doubly orbitally degenerate narrowband model with correlated hopping. The model peculiarity takes into account the matrix element of electron-electron interaction which describes intersite ...

The present paper considers ferromagnetic ordering in the Hubbard model generalized by taking into account the inter-atomic exchange interaction and the correlated hopping in a partially filled narrow band. Expressions for ...