Scalar fields and higher-derivative gravity in brane worlds [Elektronische Ressource] / submitted by Sebastian Pichler

Scalar flelds andhigher-derivative gravityin brane worldsDissertation of the faculty of physicsof theLudwig-Maximilians-Universit˜at Munc˜ hensubmitted by Sebastian Pichlerfrom TrostbergMunich, November 30, 2004Prufungsk˜ ommission:Erstgutachter: Prof. Dr. Viatcheslav MukhanovZweitgutachter: Prof. Dr. Dieter Lust˜Vorsitz: Prof. Dr. Martin FaesslerProtokollfuhrer:˜ Prof. Dr Hermann WolterErsatz: PD. Dr. Thomas Buchertdate of oral exam: May 2, 2005AbstractWe consider the brane world picture in the context of higher-derivative the-ories of gravity and tackle the problematic issues flne-tuning and brane-embedding. First, we give an overview of extra-dimensional physics, fromthe Kaluza-Klein picture up to modern brane worlds with large extra dimen-sions. We describe the difierent models and their physical impact on futureexperiments.We work within the framework of Randall-Sundrum models in which thebrane is a gravitating object, which warps the background metric. We addscalar flelds to the original model and flnd new and self-consistent solutionsfor quadratic potentials of the flelds. This gives us the tools to investigatehigher-derivativegravitytheoriesinbraneworldmodels. Speciflcally,wetakegravitational Lagrangians that depend on an arbitrary function of the Ricciscalaronly,so-calledf(R)-gravity. Wemakeuseoftheconformalequivalencebetween f(R)-gravity and Einstein-Hilbert gravity with an auxiliary scalarfleld.