The Indian Institute of Technology Bombay (IIT Bombay) is organising an Institute lecture on October 7, 2024.

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The details of the lecture are provided below:

Title: "Fluid Dynamics: From Terrestrial to Astrophysical Laboratories"

Speaker:?Prof. Nils Andersson,?Applied Mathematics, University of Southampton ?

About the speaker:?

Nils Andersson is a Professor of Applied Mathematics at the University of Southampton. He is an expert on Einstein's theory of relativity and related astrophysics and has actively pursued many issues relevant to the emerging area of gravitational wave astronomy. His current work focuses on the extreme physics that neutron stars represent, from the state and composition of matter to the dynamical role of the superfluid and superconducting components expected to be present in the core of a mature neutron star. He served as President of the International Society on General Relativity and Gravitation 2019-22 and was awarded the 2024 Karl Schwarzschild Prize in Astrophysics for his work on compact object dynamics. He has written a comprehensive textbook on gravitational-wave astronomy as well as a series of children's books introducing science concepts to younger readers.

Speaker's webpage:?https://www.southampton.ac.uk/people/5wy7j9/professor-nils-andersson

Abstract:

Fluid Mechanics is key to understanding and designing real-world systems such as land, air and space vehicles and their engines, and building ocean structures. Interestingly, the basic set of equations is key to climate modelling and prediction and also helpful in studying the formation and evolution of stars and their remnants. When dealing with extreme gravity, the equations become more complex but keep the same mathematical structure. Recent research in this area has led to a deeper understanding of the equations, especially for matter under extreme conditions. As an example, neutron star mergers are cosmic laboratories of (not particularly well-understood) physics. The modelling requires large-scale simulation of very hot and dense matter, likely far away from equilibrium conditions. The live spacetime of general relativity is an absolute requirement, as is an understanding of fluid dynamics beyond the textbook level. Framing the discussion in the context of state-of-the-art merger simulations and the need to understand the fine print of the associated signals current and future gravitational-wave detectors, I will connect a robust approach to modelling relativistic fluids (based on a variational principle) with progress in understanding out-of-equilibrium aspects (like bulk viscosity). I will also outline how we hope to deal with turbulence and small-scale fluctuations, tricky problems for everyday fluids but particularly so in general relativity.