On 8 dimensional, maximal, gauged supergravities and some higher order gravities
- Autores: Oscar Andrés Lasso Andino
- Directores de la Tesis: Tomás Ortín Miguel (dir. tes.)
- Lectura: En la Universidad Autónoma de Madrid ( España ) en 2018
- Idioma: inglés
- Número de páginas: 151
- Programa de doctorado: Programa de Doctorado en Física Teórica por la Universidad Autónoma de Madrid
- Materias:
- Enlaces
- Tesis en acceso abierto en: Biblos-e Archivo
- Resumen
This thesis focuses in various aspects of gauged 8-dimensional supergravity theories and on the study of certain higher order gravities. Supergravity theories are the limit, at low energies, of the String Theories. These theories were built in order to unify the 4 forces that exist in nature, under a unique and consistent formalism. Nowadays, scientist are trying to nd experimentally the existence of supersymmetric particles. The existence of these particles may solve some fundamental problems like the nature of dark matter and dark energy. If discovered, they would automatically make supergravity the fundamental framework for describing the Universe where we live.
In this context, studying the most general supergravity theories in di erent dimensions is very important for describing Nature. Considering that the theories that describe the known interactions are gauge theories, we expect that the theory that uni es all interactions is also a gauge theory and, in the context of this thesis, a gauged supergravity theory.
The quantization of General Relativity does not give a renormalizable Quantum Field Theory. This fact does not allow us to know the behaviour of gravity at high energies and small scales. The e ective action of any UV completion of General Relativity should contain terms with higher derivatives, involving contractions of the Riemann tensor and its covariant derivative. String Theories predict the appearance of higher order terms, which are corrections to the Einstein-Hilbert action. This provides a motivation to study theories of gravity of higher order in the curvature, known as higher-order gravities" or \modi ed gravities".
In this thesis we collect the results prsented in the publications [?,?,?].
In [?] we construct the tensor hierarchy of generic, linear, bosonic, 8-dimensional eld theories. We rst study the form of the most general 8-dimensional bosonic theory with Abelian gauge symmetries only and no massive deformations. Having constructed the most general Abelian theory, we study the most general gaugings of its global symmetries and the possible massive deformations using the embedding tensor formalism.
In [?] we study the gauging of maximal d=8 supergravity using the embedding tensor formalism and teh general results of the preceding paper. We focus on SO(3) gaugings, study all the possible choices of gauge elds and construct explicitly the bosonic actions for all these choices. We study the relation between the 8 dimensional supergravity buit by Salam and Sezgin in [?] by compacti cation of d = 11 supergravity and the theory constructed by Alonso-Alberca et al. in [?] by dimensional reduction of the so called \massive 11-dimensional supergravity" proposed by Meessen and Ort n in [?].
In [?] we study some aspects of f(Lovelock) theories in d dimensions. These theories are generalizations of the f(R) and Lovelock theories, where the gravitational action depends on an arbitrary function of the Euler densities in d dimensions. We show that these theories are equivalent to certain scalar-tensor theories, we study the linearized equations of the theory on general maximally symmetric backgrounds, and we nd constraints on the couplings of a family of ve-dimensional f(Lovelock) theories using holographic entanglement entropy. Finally, we present some new black hole solutions in di erent dimensions
