Structure and complexity of cosmological correlators
Year: 2024
Type: article
Abstract: Cosmological correlators capture the spatial fluctuations imprinted during the earliest episodes of the Universe. While they are generally very nontrivial functions of the kinematic variables, they are known to arise as solutions to special sets of differential equations. In this work we use this fact to uncover the underlying tame structure for such correlators and argue that they admit a well-defined notion of complexity. In particular, building upon the recently proposed kinematic flow algorithm, we show that tree-level cosmological correlators of a generic scalar field theory in a Friedmann-Lemaître-Robertson-Walker spacetime belong to the class of Pfaffian functions. Since Pfaffian functions admit a notion of complexity, we can give explicit bounds on the topological and computational complexity of cosmological correlators. We conclude with some speculative comments on the general tame structures capturing all cosmological correlators and the connection between complexity and the emergence of time. Published by the American Physical Society 2024
Institution: Utrecht University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4405722227