Scaling the Landscape: Robust EFT Implications from UV Physics

Abstract: The phenomenon of decoupling is a two-edged sword: it allows a robust understanding of low-energy physics without requiring detailed knowledge of UV completions, but by doing so it also hides any clues about these completions from prying low-energy eyes. There is widespread interest in finding any UV diamonds amongst the low-energy roughage, however, as is illustrated by the `swampland’ program. This program promotes the perceived difficulties in finding phenomenologically successful mechanisms (eg cosmic inflation) in string theory into a principle, by asserting that some low-energy theories do not have UV completions, so the UV information lies in what can and cannot be completed. This talk takes a different approach, arguing that EFTs coming from weakly coupled strings enjoy a pattern of approximate scaling symmetries, and it is these symmetries and their pattern of breaking that provide the robust UV information that is accessible at low energies. We argue that these symmetries (together with other low-energy symmetries) account for the widespread occurrence of no-scale supergravities in 4D string vacua, and encode attractive new mechanisms for technical naturalness. In particular, the symmetries themselves account for the rarity of (but do not predict the absence of) inflationary vacua, and the models to which they point include an enormously successful class of technically natural inflationary models (not based on axions) that come with potentially testable implications for the search for primordial gravity waves.

astrophysicscondensed mattergeneral relativity and quantum cosmologyHEP - phenomenologyHEP - theorymathematical physicsquantum physics

Audience: researchers in the topic

Quantum Aspects of Space-Time and Matter