Lamm, Valluri, Jentschura and Weniger comment on "A Convergent Series for the QED Effective Action" by Cho and Pak [Phys. Rev. Lett. vol. 86, pp. 1947-1950 (2001)]

TL;DR

This paper critiques the claims of Cho and Pak regarding a logarithmic correction in the QED effective action, emphasizing that their physical significance remains unproven and referencing prior complete series representations.

Contribution

It provides a critical comment on Cho and Pak's work, reaffirming the validity of previous convergent series results and questioning the physical interpretation of their correction term.

Findings

Previous series representations are complete and correct.

The significance of the logarithmic correction remains unproven.

Prior work supports the validity of the effective action expressions.

Abstract

Complete results were obtained by us in [Can. J. Phys. 71, 389 (1993)] for convergent series representations of both the real and the imaginary part of the QED effective action; these derivations were based on correct intermediate steps. In this comment, we argue that the physical significance of the "logarithmic correction term" found by Cho and Pak in [Phys. Rev. Lett. 86, 1947 (2001)] in comparison to the usual expression for the QED effective action remains to be demonstrated. Further information on related subjects can be found in Appendix A of hep-ph/0308223 and in hep-th/0210240.