General Meeting: Speaker: Sebastian Murk

On the 3rd Tuesday of the month (February to November) at 7:30pm, we meet on zoom or at Regis Hall in the grounds of St Ignatius’ College, Riverview Street, Riverview (Lane Cove) which features a presentation from a Guest Lecturer. These presentations generally focus on the theoretical aspects of Cosmology, Astrophysics and Astrophotography and can include some of the most up-to-date research and scientific findings. We are fortunate to be able to obtain speakers from Australia’s top universities and scientific community – our past Guest Lecturers have included the likes of Dr Fred Watson and Nobel Prize winner Prof. Brian Schmidt. Our speaker this month is Sebastian Murk from Macquarie University, who will be speaking on quantum physics and relativity. Title and abstract follow:

Title:

Black holes in semiclassical and modified theories of gravity

Abstract:

Our physical understanding of the world currently rests on two fundamental frameworks: general relativity, which describes gravitational interactions, and quantum field theory, which describes all non-gravitational interactions. While both theories have been spectacularly successful in predicting physical phenomena within their respective domains of validity, foundational differences imply that they cannot be simultaneously correct. This is not only unsatisfactory from a logical viewpoint, but also means that we lack predictive power in the regime where both gravitational and quantum effects simultaneously play a role, such as the physics of black holes, early universe cosmology, and spacetime geometry at the Planck scale. My talk will focus on our understanding of black holes and their horizons in the frameworks of semiclassical and modified theories of gravity. Despite the lack of a fully developed theory of quantum gravity, these two theoretical frameworks allow us to incorporate quantum effects into the gravitational dynamics of black holes, which is of crucial importance for a complete description of their evolution and includes processes such as their formation and possible evaporation. I will introduce core concepts and present an overview of interesting recent developments and new results.

The format of the evening consists of a welcome to Members and Visitors, a quick discussion on general business of NSAS, the presentation from our Guest Speaker and then members usually stay and have a chat with a cup of tea or coffee.

These meetings are an excellent opportunity to get to know fellow members.