Gated sets in metric spaces

The concept of a gated subset in a metric space is studied, and it is shown that properties of disjoint pairs of gated subsets can be used to investigate projections in Tits buildings.Dedicated to Professor Otto Haupt with best wishes on his 100th birthday     

Zur Stetigkeit der mengenwertigen metrischen Projektion in endlichdimensionalen Räumen

Let X be a real normed linear space, X^* its dual, V a linear subspace of X and S(V) the unit sphere in the orthogonal space In this note we prove in the case of finite-dimensional X the following sufficient condition for the continuity of the set-valued metric projection in terms of the mapping and : If the restriction of T to S(V) is lower semi-continuous then P_V is lower semi-continuous.     

Structure effects in dissipative collisions

An ansatz representing a generalisation of the one-body recoil formula is proposed on the basis of the total kinetic energy loss versus σ_Z² correlation systematics observed in collisions between very heavy nuclei. It is shown that such correlations are surprisingly sensitive to the shell structure of the colliding nuclei. The mechanism of energy dissipation appears also to be strongly influenced by the structure effects.     

Das Definitionsgebiet der Grundinvarianten eines Tensors

In this article we investigate the conditions that the principal invariants of a tensor have to satisfy so that it may be symmetric or orthogonal. In particular, we treat the relationship between the domain of definition of the principal invariants of a symmetric deviator and the space of its eigenvalues, and we apply this mapping to the yield conditions ofTresca and ofv. Mises.