The absolute swampland
Astrid Eichhorn, Arthur Hebecker, Jan M. Pawlowski, Johannes Walcher
Abstract
Abstract The “Swampland Program” aims to discriminate consistent-looking effective field theories that do not admit a UV completion in quantum gravity from those that do. While most often developed under the umbrella of string theory, several swampland criteria have been explored also in other contexts, especially asymptotically safe gravity. A comparison between different approaches can help to clarify the dependence of low-energy constraints on UV physics and thereby shed light on the universality of quantum gravity itself. In this perspective we summarise what is known about three important swampland conjectures in string theory and in asymptotic safety. We point out future lines of research that can help to understand to what extent swampland conjectures are absolute, i.e. , hold in quantum gravity in general, or relative, i.e. , belong only to a specific UV framework.