The Co-Points of Rays are Cut Points of Upper Level Sets for Busemann Functions

We show that the co-rays to a ray in a complete non-compact Finsler manifold contain geodesic segments to upper level sets of Busemann functions. Moreover, we characterise the co-point set to a ray as the cut locus of such level sets. The structure theorem of the co-point set on a surface, namely that is a local tree, and other properties follow immediately from the known results about the cut locus. We point out that some of our findings, in special the relation of co-point set to the upper lever sets, are new even for Riemannian manifolds

Supersymmetric Toda lattice hierarchies

The origin of the bosonic and fermionic solutions, constructed in [1,2,3], to the symmetry equations corresponding to the two-dimensional bosonic and N=(2|2) supersymmetric Toda lattices is established, and algebras of the corresponding symmetries are derived. The conjecture regarding an N=(2|2) superfield formulation of the N=(2|2) supersymmetric Toda lattice hierarchy, proposed in [16], is proved. The two-dimensional N=(0|2) supersymmetric Toda lattice hierarchy is proposed and its N=(0|2) superfield formulation is discussed. Bosonic and fermionic solutions to the symmetry equation corresponding to the two-dimensional N=(0|2) supersymmetric Toda lattice equation and their algebra are constructed. An infinite class of new two-dimensional supersymmetric Toda-type hierarchies is discussed.Comment: 38 pages LaTeX, to be published in Proceedings of the NATO ARW ``Integrable Hierarchies and Modern Physical Theories'' (Chicago, USA, July 22 - 26, 2000), Kluwer Academic Publisher