Date: 27 SEPTEMBER 2022 from 14:30 to 15:30
Most of our observations that characterize space and time are expressed in terms of non-local, bi-tensorial objects such as geodesic or null intervals between events and two-point (Green's) functions. In this talk, I will highlight the importance of characterizing spacetime geometry in terms of two fundamental bi-tensors, Synge's World function and the van Vleck determinant. I will first discuss two specific recent results that employ these objects: (i) Non-perturbative tidal corrections to results such as Unruh effect and ageing of twins, and (ii) Formulating generalised uncertainty principle on curved space(time)s. I will then describe a formalism to construct an effective quantum metric - qmetric - in terms of these bi-tensors, which can describe spacetime with a zero point length. Some non-trivialities of the qmetric, its classical limit, and its role in quantum gravity will then be discussed.