ar X iv : c on d - m at / 9 90 50 81 v 1 6 M ay 1 99 9 Analysis of the approximations used in the van Hove - BCS theory

ar X iv : n uc l - th / 9 90 50 49 v 2 2 6 M ay 1 99 9 η - and η ′ - meson production in the reaction pn → dM near threshold

ar X iv : m at h - ph / 9 90 50 22 v 1 2 7 M ay 1 99 9

K-theory allows us to define an analytical condition for the existence of 'false' gauge field copies through the use of the Atiyah-Singer index theorem. After establishing that result we discuss a possible extension of the same result without the help of the index theorem and suggest possible related lines of work.

ar X iv : n uc l - th / 9 90 50 49 v 1 2 1 M ay 1 99 9 η - and η ′ - meson production in the reaction pn → dM near threshold

ar X iv : c on d - m at / 9 90 50 41 v 1 4 M ay 1 99 9 Heavy - Fermions in a Transition - Metal Compound : LiV

The recent discovery of heavy-Fermion properties in Lithium Vanadate and the enormous difference in its properties from the properties of Lithium Ti-tanate as well as of the manganite compounds raise some puzzling questions about strongly correlated Fermions. These are disscussed as well as a solution to the puzzles provided.

ar X iv : p at t - so l / 9 90 50 05 v 1 2 1 M ay 1 99 9 Discrete breathers in systems with homogeneous potentials - analytic solutions

We construct lattice Hamiltonians with homogeneous interaction potentials which allow for explicit breather solutions. Especially we obtain exponentially localized solutions for d-dimensional lattices with d = 2, 3.