Bruno Nachtergaele
Quasi-state decompositions for quantum spin systems,
(70K, Plain TeX)

ABSTRACT.  I discuss the concept of quasi-state decompositions for ground states and
equilibrium states of quantum spin systems.  Some recent results on the
ground states of a class of one-dimensional quantum spin models are 
summarized and new work in progress is presented. I also outline some 
challenging open problems and conjectures.