Article
Covariant non-local action for massless QED and the curvature expansion
Journal of High Energy Physics
(2015)
Abstract
We explore the properties of non-local effective actions which include gravitational
couplings. Non-local functions originally defined in flat space can not be easily
generalized to curved space. The problem is made worse by the calculational impossibility of
providing closed form expressions in a general metric. The technique of covariant perturbation
theory (CPT) has been pioneered by Vilkovisky, Barvinsky and collaborators whereby
the effective action is displayed as an expansion in the generalized curvatures similar to
the Schwinger-De Witt local expansion. We present an alternative procedure to construct
the non-local action which we call non-linear completion. Our approach is in one-to-one
correspondence with the more familiar diagrammatic expansion of the effective action. This
technique moreover enables us to decide on the appropriate non-local action that generates
the QED trace anomaly in 4D. In particular we discuss carefully the curved space generalization
of ln_, and show that the anomaly requires both the anomalous logarithm as well
as 1/_ term where the latter is related to the Riegert anomaly action.
Keywords
- physics
Disciplines
Publication Date
2015
DOI
10.1007/JHEP10(2015)044
Citation Information
John Donoghue and Basem K Mahmoud El-Menoufi. "Covariant non-local action for massless QED and the curvature expansion" Journal of High Energy Physics (2015) Available at: http://works.bepress.com/john_donoghue/172/