Asymptotic Behaviour of a Dynamic Local Field: Is the Order of the K Approaches Limit of Infinity and Omega Approaches Limit of Infinity Limits Interchangeable in an Interacting Many-Body System.

摘要

The wavevector- and frequency-dependent susceptibility chi (omega) sub k in many- body theory is customarily expressed in terms of a dynamic local field term Gk(w). For k approaches infinity there are certain asymptotic forms for G (omega) sub k due to Shaw and to Niklasson. It is shown that they represent the two different orders of the k approaches infinity and w approaches infinity limits. The validity of our result is tested in an exactly solvable physical system. Reprints. (jhd)