22.02.2023 (Wednesday)

Keeping matter in the loop in de Sitter quantum gravity

Regular Seminar Jackson Fliss (University of Cambridge)

at:
13:45 KCL
room K0.16
abstract:

Chern-Simons (CS) theory provides an attractive framework for quantizing 3d gravity, at least around a fixed saddle-point. But how do we describe matter in CS gravity while retaining its useful features? In this talk I will focus on the CS description of Euclidean de Sitter space about its three-sphere saddle. I will introduce a "Wilson spool," which can be interpreted as a collection of Wilson loops winding arbitrarily many times around the three-sphere and which provides an effective description of massive one-loop determinants. Constructing and subsequently evaluating the spool will require us to revisit starting assumptions about unitarity of the representations appearing in the Wilson loops as well as the library of "exact methods" available to CS theories on the three-sphere. The result will be an object that reduces to the scalar one-loop determinant on the three-sphere in the limit that Newton's constant vanishes yet can be evaluated at in any order in G_N perturbation theory. Time remaining, I will either discuss potential further applications of the Wilson spool (either to spinning fields or to contexts outside of de Sitter) or (unresolved) implications of CS gravity for the dS/CFT dictionary.