Speaker
Dr
Duifje van Egmond
(Ecole Polytechnique, Palaiseau)
Description
Abstract
An essential aspect of gauge theories is that all physical observable quantities have to be gauge-invariant. In practice, however, the explicit calculations of the S-matrix elements and corresponding cross sections are done by employing the non-gauge-invariant elementary fields. This is not always problematic, as sometimes gauge independence is guaranteed by symmetry identities. In other cases, however, gauge-invariance has to be implemented. In this talk I will discuss two different ways to do so: one based on the Fröhlich-Morchio-Strocchi conjecture for the electroweak theory, another based on recent work on the centersymmetric Landau gauge, which leaves essential physical symmetries intact after gauge-fixing.
Author
Dr
Duifje van Egmond
(Ecole Polytechnique, Palaiseau)
