Symmetry and holonomy in M Theory

TL;DR

This thesis explores the role of generalized holonomy and enlarged supersymmetry algebras in classifying solutions and understanding the gauge structure of D=11 supergravity, with implications for M Theory and preonic states.

Contribution

It introduces the use of generalized holonomy and expansion methods to analyze supergravity solutions and proposes models involving tensorial spaces and preonic states in M Theory.

Findings

Generalized curvature contains supergravity equations of motion.

Enlarged supersymmetry algebras relate to gauge symmetry of supergravity.

A string in tensorial space describes preonic excitations with 30 preserved supersymmetries.

Abstract

In this PhD Thesis, supersymmetry and its formulation in the context of D=11 supergravity is discussed from several perspectives. The role of generalized holonomy as a classification tool of supersymmetric supergravity solutions is reviewed, with particular emphasis on how successive supercovariant derivatives of the generalized curvature may be needed to properly define the generalized holonomy algebra. The generalized curvature is also shown to contain the supergravity equations of motion, even in the non-vanishing gravitino case. The underlying gauge symmetry of D=11 supergravity is discussed and argued to become manifest when its three-form field A_3 is expressed through a set of one-form gauge fields, associated with the generators of a suitable family of enlarged supersymmetry algebras. This family is related to osp(1|32) through expansion, a method to obtain new Lie (super)algebras of increasing dimensions from given ones. The analysis of the underlying gauge symmetry of D=11 supergravity leads naturally to enlarged supersymmetry algebras and superspaces making, thus, natural to consider actions for objects moving in such spaces. In particular, a string moving in tensorial space is discussed, describing the excitations of a state preserving 30 out of 32 supersymmetries (hence composed of two preons, hypothetical constituents of M Theory preserving 31 supersymmetries). A G-frame method is also discussed to study hypothetical preonic solutions of supergravity.