Swampland distance conjectures and geometric flow equations

Freigang, Julian (2023): Swampland distance conjectures and geometric flow equations. Dissertation, LMU München: Fakultät für Physik

Abstract

The Swampland Program aims to distinguish between those effective field theories, which can be completed into Quantum Gravity at high energies, and those which can't. The distinction between these two sets is made by the so called Swampland Conjectures which can put severe constraints on an effective field theory. These conjectures are usually motivated by general black hole arguments, holography or directly String Theory. Moreover, many of these seem to be intertwined in a web of conjectures hinting at a more fundamental principle yet to be uncovered. One of the most important and best studied conjectures is the Swampland Distance Conjecture (SDC) which lies at the heart of this thesis. It limits the scalar field space distance which can be traversed in an effective field theory before the theory has to break down due to an infinite tower of states becoming massless. Over the last years the conjecture was generalized in many different ways. For instance, a close relation to geometric flows has recently been found, which has sparked some interest in geometric flows within the Swampland community. Furthermore, the SDC is supposed to hold for geodesic field space trajectories, but it was shown that the validity of the SDC can be extended to a non-geodesic motion in field space. The purpose of this thesis now is twofold: On the one hand, motivated by the connection to the SDC new geometric flows are constructed and studied. This includes a geometric flow equation for the number of spacetime dimensions and an extension of Ricci flow which incorporates the backreaction of matter fields. On the other hand, the SDC is applied to the scenario of cosmic acceleration, which is still an open and significant problem in physics. It turns out that the non-geodesicity of trajectories is bounded by consistency with the SDC near the boundary of field space.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 530 Physik
• Fakultäten: Fakultät für Physik
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 26. Juli 2023
• 1. Bericht­erstatter:in: Lüst, Dieter