ar X iv : c on d - m at / 9 40 10 12 v 2 1 2 Ja n 19 94 December 1993 Bosonization of current - current interactions

ar X iv : c on d - m at / 9 40 10 66 v 1 2 8 Ja n 19 94 Ground state energy and quasiparticle gaps

ar X iv : c on d - m at / 9 40 10 05 v 2 1 0 Ja n 19 94 Composite operators for BCS Superconductor

The new form of the composite operator generalizing the Cooper pairs for a BCS superconductor is introduced. The approach is similar to the derivation of the composite operator of the odd-frequency superconductors. The examples of the d x 2 −y 2 −, d xy − and p− wave composite operators for a 2D t − J model are given.

ar X iv : h ep - t h / 93 01 10 9 v 1 2 6 Ja n 19 93 String inspired effective Lagrangian and Inflationary Universe

We consider a string inspired effective Lagrangian for the graviton and dilaton, containing Einstein gravity at the zero slope limit. The numerical solution of the problem shows asymptotically an inflationary universe. The time is measured by the dilaton, as one expects. The result is independent of the introduction of ad-hoc self interactions for the dilaton field.

ar X iv : c on d - m at / 9 50 10 40 v 1 1 1 Ja n 19 95 Coherent States of Alternating Current . ( February 1 , 2008 )

We study counting statistics of electric current pumped by pulses of an external field. The fluctuations depend on the pulse shape, and can be minimized by choosing the pulse shape properly. For an optimal pulse shape, the fluctuations are reduced to the dc level, i.e., they do not depend on the duty cycle of the signal. We develop an approach that allows to calculate all counting statistics fo...

ar X iv : c on d - m at / 9 60 10 94 v 1 2 2 Ja n 19 96 Excitons in insulating cuprates

We study the electronic excitations near the charge-transfer gap in insulating CuO 2 planes, starting from a six-band model which includes p π and d xy orbitals and Cu-O nearest-neighbor repulsion U pd. While the low lying electronic excitations in the doped system are well described by a modified t−J model, the excitonic states of the insulator include hybrid d xy − p π states of A 2g symmetry...