Tübingen 2003 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 46: Theorie VII
HK 46.1: Gruppenbericht
Donnerstag, 20. März 2003, 16:30–17:00, D
Vacuum Energies in Renormalisable Quantum Field Theories — •M. Quandt1,2, N. Graham3, R.L. Jaffe2, V. Khemani2, M. Scandurra2, and H. Weigel1 — 1Institute for Theoretical Physics, University of Tübingen, 72076 Tübingen, Germany. — 2Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge MA 02139, USA — 3Department of Physics, Middlebury College, Middlebury VT 05753, USA
Many problems in quantum field theory (QFT) require efficient tools to calculate functional determinants or vacuum energies in non-trivial background fields. We present a general approach [1] to compute renormalised one-loop quantum energies and energy densities. Our method employs analytical properties of scattering data to compute Green’s functions at imaginary momenta. By identifying the Born series to the Green’s function with the Feynman expansion, our scheme allows for a conventional renormalisation using standard counterterms and renormalisation conditions. The resulting expressions for the energy and energy density are very well-suited for numerical investigations.
Our computational method is particularly useful for the study of singular and strongly coupled background fields. This situation is a renormalisable QFT model for the classical Casimir problem [2] which is usually posed as the response of a quantum field to externally imposed boundary conditions. We illustrate cases where the subtleties of the QFT treatment invalidate the conclusions of the boundary condition approach.
[1] N. Graham et al., Nucl. Phys. B645 (2002) 49.
[2] N. Graham et al., hep-th/0207205.