Hal Tasaki
Uniqueness of Ground State in
Exactly Solvable Hubbard, Periodic Anderson, and Emery Models
(26K, LaTeX)

ABSTRACT.  We study the exactly solvable strongly interacting electron 
models recently introduced by Brandt and Giesekus, and further
generalized  by other authors.
 For a very general class of models, including the Hubbard, the 
periodic Anderson, and 
the Emery models with certain hopping matrices and infinitely large 
on-site 
Coulomb repulsion on d-sites, we prove that the known exact ground 
sate is 
indeed the unique ground state
for a certain electron number.
The uniqueness guarantees that one can discuss physics of various 
strongly 
interacting electron systems by analyzing the exact ground states.
(This file lacks the figure.
I also mail a PS version of the same paper with the figure.)