Peter Szekeres

Peter Szekeres (ˈsɛkɛrɛʃ; born 7 August 1940) is an Australian mathematical physicist born to Hungarian parents. He has made significant contributions to general relativity and theoretical cosmology. He is particularly well known for exact solutions of Einstein's field equations with important applications in astrophysics. These include colliding gravitational waves, and inhomogeneous cosmological models. The latter, known as the Szekeres models, can also be applied to the problem of gravitational collapse. The Szekeres cosmologies are the simplest exact models which contain both the standard Friedmann–Lemaître–Robertson–Walker model and the spherically symmetric Lemaître–Tolman solution in particular limits. They also account for more general aspects of Einstein's theory, and are increasingly used to model nonspherical structures—walls, filaments, nodes and voids—that are typical in the cosmic web.
==Early life and education==
Szekeres was born in Shanghai, China to mathematician parents George Szekeres and Esther Szekeres. His parents were from Budapest, but fled to escape the threat of Nazi persecution. Szekeres' father George obtained a job in Shanghai as a leather chemist, having worked as an analytical chemist for six years in Budapest.
In June 1948, at the age of 7, Szekeres and his parents moved to South Australia, where his father took up a position as lecturer in mathematics at the University of Adelaide. Peter Szekeres also took his own first degree in mathematics at Adelaide, and described the most significant event of his undergraduate years as being a visit in 1960 by Hermann Bondi who gave a public lecture entitled “Why is the sky dark at night?”. Awarded a Commonwealth scholarship later in the year, Szekeres wrote to Bondi asking whether he could do a PhD with him on cosmology. Surprisingly, Bondi replied that nothing much was happening in cosmology, and recommended Szekeres do general relativity with his colleague Felix Pirani. For Szekeres this was a fortunate turn of events as he found Pirani to be a wonderful supervisor, who really enjoyed spending time with his students.
==Career and research==
From his early PhD research, and throughout his career, Szekeres combined the deep mathematical aspects of general relativity with their consequences for astrophysics and cosmology. His "gravitational compass" gives a first principles description of how to experimentally measure the spacetime curvature of an arbitrary gravitational field.
After completing his PhD in 1965, Szekeres held a postdoctoral fellowship at Cornell University. His work with Petrosian and Salpeter on cosmologies with a non-zero cosmological constant gained attention at a time that the first quasar surveys were conducted.
In 1967 Szekeres returned to Kings College to take up an academic position. While there he found the first exact solution for colliding gravitational waves.
In 1971 Szekeres moved back to the University of Adelaide to take up a lectureship at the Department of Mathematical Physics. He produced his most important work there. This includes the Bell-Szekeres geometries for interacting electromagnetic shock waves that produce gravitational waves, and also the Szekeres cosmological models, which include models of quasispherical gravitational collapse.
After retiring from the teaching staff at the University of Adelaide, Szekeres completed an authoritative 600 page textbook.'A Course in Modern Mathematical Physics: Groups, Hilbert Space and Differential Geometry by Peter Szekeres, 2009 
==Books==
*Peter Szekeres, A Course in Modern Mathematical Physics: Groups, Hilbert Space and Differential Geometry (2009) 
==Personal life==
Szekeres is married to Angela Weeks, recipient of the 2021 OAM.> Full List South Australias 2021 Queens Birthday honours recipients
Category:1940 births
Category:Australian mathematicians
Category:Australian physicists
Category:Australian people