Transplanckian censorship and the local swampland distance conjecture

• Published in: The journal of high energy physics Vol. 2020; no. 1; pp. 1 - 17
• Main Authors: Draper, Patrick, Farkas, Szilard
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2020; Springer Nature B.V; SpringerOpen
• Subjects: Black Holes; Bubbles; Censorship; Charging; Classical and Quantum Gravitation; Dilatons; Effective Field Theories; Elementary Particles; Excitation; Field Theories in Higher Dimensions; Field theory; High energy physics; Models of Quantum Gravity; Pair production; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum gravity; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Field Theories in Higher Dimensions; Effective Field Theories; Black Holes; Models of Quantum Gravity
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP01(2020)133

A bstract The swampland distance conjecture (SDC) addresses the ability of effective field theory to describe distant points in moduli space. It is natural to ask whether there is a local version of the SDC: is it possible to construct local excitations in an EFT that sample extreme regions of moduli space? In many cases such excitations exhibit horizons or instabilities, suggesting that there are bounds on the size and structure of field excitations that can be achieved in EFT. Static bubbles in ordinary Kaluza-Klein theory provide a simple class of examples: the KK radius goes to zero on a smooth surface, locally probing an in- finite distance point, and the bubbles are classically unstable against radial perturbations. However, it is also possible to stabilize KK bubbles at the classical level by adding flux. We study the impact of imposing the Weak Gravity Conjecture (WGC) on these solutions, finding that a rapid pair production instability arises in the presence of charged matter with q/m ≳ 1. We also analyze 4d electrically charged dilatonic black holes. Small curvature at the horizon imposes a bound log ( M BH ) ,≳ | ∆𝜙 | , independent of the WGC, and the bound can be strengthened if the particle satisfying the WGC is sufficiently light. We conjecture that quantum gravity in asymptotically flat space requires a general bound on large localized moduli space excursions of the form | ∆𝜙 | ≲ | log( R Λ) | , where R is the size of the minimal region enclosing the excitation and Λ − 1 is the short-distance cutoff on local EFT. The bound is qualitatively saturated by the dilatonic black holes and Kaluza-Klein monopoles.