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...

The LeChatelier-Samuelson principle ("the principle") states that as a reaction to a shock, an agent's short-run adjustment of an action is smaller than the long-run adjustment of that action when the other related actions can also be adjusted. We extend the principle to strategic environments...

We examine a multinational firm which has a decreasing marginal cost, and the optimal sales tax policies of the regions where that firm operates. We show that the regions set higher sales taxes than those given by a cooperative equilibrium. Each region fails to fully internalize the effects of...

We show that a monopolist's problem of optimal advance selling strategy can be mathematically transformed into a problem of optimal bundling strategy if four conditions hold: i. consumers and the firm agree on the probability of the states occurring, ii. the firm pre-commits to the spot prices...

The LeChatelier-Samuelson principle states that as a reaction to a shock, an agent's short-run adjustment of an action is smaller than the long-run adjustment of that action when the other related actions can also be adjusted. We extend the principle to strategic environments and define long run...

Monopolists selling complementary products charge a higher price in a static equilibrium than a single multiproduct monopolist would, reducing both the industry profits and consumer surplus. However, firms could instead reach a Pareto improvement by lowering prices to the single monopolist...