A two component model of negative U centers coupled with the Fermi sea of itinerant fermions is discussed in connection with high-temperature superconductivity of cuprates, and superfluidity of atomic fermions. We examine the phase transition and the condensed state of this boson-fermion model...

With the superconducting cuprates in mind, a set of unitary transformations was used to decouple electrons and phonons in the strong-coupling limit. While phonons remain almost unrenormalised, electrons are transformed into itinerent singlet and triplet bipolarons and thermally excited polarons....

Magnetoresistance (MR) of Bi-2212 single crystals with <InlineEquation ID="Equ5"> <EquationSource Format="TEX">$T_{c} \approx 87-92$</EquationSource> </InlineEquation> K is studied in pulsed magnetic fields up to 50 T along the c-axis in a wide temperature range. The negative out-of-plane and the positive in-plane MRs are measured in the normal state. Both MRs have similar...</equationsource></inlineequation>

The question of the economic role of the state budget in social reproduction under socialism is not yet adequately worked out. Yet it is of great importance for the theory of Soviet finance, as well as for financial practice. Therefore one has to stress the importance and timeliness of the...