Guest Charge and Potential Fluctuations in Two-Dimensional Classical Coulomb Systems

Abstract

A known generalization of the Stillinger-Lovett sum rule for a guest charge immersed in a two-dimensional one-component plasma (the second moment of the screening cloud around this guest charge) is more simply retrieved, just by using the BGY hierarchy for a mixture of several species; the zeroth moment of the excess density around a guest charge immersed in a two-component plasma is also obtained. The moments of the electric potential are related to the excess chemical potential of a guest charge; explicit results are obtained in several special cases.Comment: 21 pages. Latex. Appendix moved, with changes, to new subsection 2.3. Description of the Appendix at the end of the Introduction, from an earlier version, delete