28 September 2026 to 2 October 2026
Kavli IPMU
Asia/Tokyo timezone

Quantum Gravity Corrections: From Background Dynamics to Cosmological Perturbations

29 Sept 2026, 15:45
15m
Lecture Hall (Kavli IPMU)

Lecture Hall

Kavli IPMU

Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8583, Japan

Speaker

Hongguang Liu

Description

Effective quantum gravity models often specify corrections to homogeneous cosmological evolution, leaving open how these corrections extend to cosmological perturbations. I will present a framework for constructing scalar and tensor perturbations around a given modified FLRW background. Here, spatial covariance and a Birkhoff-type vacuum requirement constrain its extension to inhomogeneous geometries. For a specified matter realization and class of local actions, the resulting response to curvature and anisotropy determines the quadratic perturbation action and the corresponding Mukhanov–Sasaki equations. As an example, I will consider an effective model motivated by loop quantum gravity with a canonical inflaton and discuss its propagation properties, stability conditions, and general-relativistic limit.

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