QGU Guest Seminar.
Speaker: Heng-Yu Chen (National Taiwan University)
Title: "Exploring Complex Saddles and Geometries through Holography"

Abstract: Studying gravitational path integral often leads one to encounter complex saddles and the corresponding geometries, some may have interesting physical interpretations while others may be unphysical, it is therefore interesting to study them through the lens of holography. In this talk, I will report some recent progresses in this direction by applying holography correspondence for both asymptotically Anti de-Sitter and de-Sitter spacetimes. We employ the suitable analytic continuations of dual CFT correlation functions, the method of mini-superspace, and resurgence to explore these complex saddles. In the process we will provide the geometric interpretations for them, which are consistent with the holography correspondences. The work was done in collaborations with Yasuaki Hikida, Yusuke Taki and Takahiro Uetoko.