ANALYSIS OF THE THOULESS COHERENT-STATE USING THE 1 K EXPANSION/

The many-electron problem in a spin-orbital basis of rank K, with a Ha miltonian exhibiting the unitary group U(K) (the coherence group), glo bal symmetry is treated as a detailed example of the technique often r eferred to as the 1/K expansion. This approach introduces a free param eter K, which is a measure of the number of dynamical variables and us ually also invokes coherent states associated with the coherence group . We choose the Thouless coherent state, transform the complex state p arameters so that they exhibit the structure of a flat generalized pha se space, and analyze the corresponding energy functional as a power s eries in 1/K. The limit of large K and that of a large number of elect rons are discussed and compared to the expected classical limit.