95 research outputs found
Gauge principle and QED
One of the major developments of twentieth century physics has been the
gradual recognition that a common feature of the known fundamental interactions
is their gauge structure. In this talk the early history of gauge theory is
reviewed, emphasizing especially Weyl's seminal contributions of 1918 and 1929.Comment: Invited talk at PHOTON2005, 31.8-04.09, 2005, Warsaw, 19 page
The Membrane Model of Black Holes and Applications
These lectures provide a detailed introduction to the electro- dynamics of
black holes. A simplified derivation of the basic membrane equations for
stationary, axisymmetric black holes is given. The general theory is applied to
idealized current generators involving rotating black holes, and we also
analyse the Blandford-Znajek process for magnetic energy extraction from
rotating black holes.Comment: 41 pages Latex document. 11 postscript figures available at
ftp://130.60.164.117/pub/Straumann_Bad_Honnef/Straumann_Bad_Honnef_Bilder.tgz
Lecture held at the 179. WE-Heraeus-Seminar, 18-22 of August 1997 at Bad
Honnef (Germany). To be published in: Black Holes: Theory and Observation
eds. F.W. Hehl, C. Kiefer and R. Metzler, Springer 199
Proof of a decomposition theorem for symmetric tensors on spaces with constant curvature
In cosmological perturbation theory a first major step consists in the
decomposition of the various perturbation amplitudes into scalar, vector and
tensor perturbations, which mutually decouple. In performing this decomposition
one uses -- beside the Hodge decomposition for one-forms -- an analogous
decomposition of symmetric tensor fields of second rank on Riemannian manifolds
with constant curvature. While the uniqueness of such a decomposition follows
from Gauss' theorem, a rigorous existence proof is not obvious. In this note we
establish this for smooth tensor fields, by making use of some important
results for linear elliptic differential equations.Comment: 4 pages, accepted for publication in Annalen der Physi
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