Multiloop stringlike formulas for QED.

One-Loop Electron Vertex in Yennie Gauge

We derive a compact Yennie gauge representation for the off-shell one-loop electron-photon vertex, and discuss it properties. This expression is explicitly infrared finite, and it has proved to be extremely useful in multiloop calculations in the QED bound state problem.

Multiloop calculations in the string-inspired formalism: The single spinor loop in QED.

ar X iv : h ep - t h / 96 11 04 5 v 1 7 N ov 1 99 6 Multiloop Feynman Integrals in the Worldline Approach ∗

We explain the concept of worldline Green functions on classes of multiloop graphs. The QED β – function and the 2-loop Euler-Heisenberg Lagrangian are discussed for illustration. HD-THEP-96/44 HUB-EP-96/29 ∗Talk presented by M.G.Schmidt at the Dubna Joint Meeting: International Seminar on Path Integrals: Theory and Applications, and 5th International Conference on Path Integrals from meV to Me...

Schwinger pair creation of particles and strings

I shortly review the worldline instanton method for calculating Schwinger pair production rates in (i) one-loop QED (ii) multiloop QED and (iii) one-loop open string theory. 1. History Already in 1931 F. Sauter [1] realized that Dirac’s theory of the electron predicts that an electric field of sufficient strength and extent can induce spontaneous creation of electron – positron pairs from the v...

String-derived renormalization of Yang-Mills theory

We review the application of bosonic string techniques to the calculation of renormalization constants and effective actions in Yang-Mills theory. We display the multiloop string formulas needed to compute Yang-Mills amplitudes, and we discuss how the renormalizations of proper vertices can be extracted in the field theory limit. We show how string techniques lead to the background field method...