Star-UBB Seminar Series:- Modified theories of gravity- a unified approach to metric and metric-affine models
The talk begins with a general overview of General Relativity(GR) focussing on the basic ingredients of its mathematical structure. This will naturally lead the way to consider various modifications or extensions of General Relativity, many of which have been studied recently. The speaker will briefly review metric-affine models and how these fit into GR. Next he will discuss modified gravity models based on generalised geometries and on actions no longer linear in curvature. The main part of the talk will discuss how these many different theories can be studied using a single unified approach which also shows the equivalence of some of these models. We will finish off by showing a cosmological application where torsion drives a period of early-time inflation without affecting the late-time matter dominated behaviour. No matter sources are required to drive inflation and it becomes a purely geometrical effect.
頻道：Zoom ID:853-7454-4159 ←
講者：Prof. Christian G. Boehmer (Department of Mathematics, University College London, Gower Street, London WC1E 6BT, United Kingdom)
Scientific and Technological Advanced Research- Babeș-Bolyai University(Star-UBB) Seminar Series in Gravitation, Cosmology and Astrophysics
Presently a period of rapid and intense change are being witnessed in our understanding of the gravitational force, at a rate that is quickly increasing since the important observational discoveries of the late 1990s. With the advent of new observational techniques, the emergence of important cosmological and astrophysical paradigms can be seen that lead to a deep change in our understanding of the Universe. Astronomical observations strongly suggest that at large scales the force of gravity may not behave according to standard general relativity, and that a generalization of the gravitational action, either at the geometric level, or at the matter level, may be required for a full understanding of the gravitational interaction.
The goal of the present seminar is to bring Theoretical Gravitational Physics closer to the observations and experiments, and to discuss current topics in general relativity, high-energy physics, astrophysics and cosmology.