Necessary Conditions for N-Representability of Reduced Density Matrices
Alan Coleman · Journal of Mathematical Physics · 1972
In this work a large new class of extreme points of the set of N-representable 2-matrices is obtained. They correspond to the exact ground state of an operator B(g) which generalizes the BCS Hamiltonian. Further, three hitherto unpublished necessary conditions for N-representability are obtained.