Neil Turok (PhD Imperial College London, 1983) holds the Mike and Ophelia Lazaridis Niels Bohr Chair in Theoretical Physics at Perimeter Institute. He was Perimeter's Director from 2008 to 2019, in recognition of which he was awarded the title of Director Emeritus. Previously, he was Professor of Physics at Princeton University and Chair of Mathematical Physics at the University of Cambridge.
Turok’s research focuses on developing fundamental theories of cosmology and new observational tests. His predictions for the correlations of the polarization and temperature of the cosmic background radiation (CBR) and of the galaxy-CBR correlations induced by dark energy have been confirmed in detail, as significant substantiating evidence for the standard concordance cosmology. With Stephen Hawking, he discovered instanton solutions describing the birth of inflationary universes. His work on open inflation forms the basis of the widely discussed multiverse paradigm. With Paul Steinhardt, he developed an alternative, cyclic model for cosmology, whose predictions are so far in agreement with all observational tests.
Among his many honours, Turok was awarded Sloan and Packard Fellowships and the James Clerk Maxwell medal of the Institute of Physics (UK). He is a Canadian Institute for Advanced Research (CIFAR) Fellow in Cosmology and Gravity and a Senior Fellow of Massey College in the University of Toronto. In 2012, Turok was selected to deliver the CBC Massey Lectures, broadcast across Canada. The lectures were published as The Universe Within, a bestseller which won the 2013 Lane Anderson award, Canada's top prize for popular science writing. In 2018, Turok was named an Officer of the Order of Canada (Honorary) in recognition of his “substantial contributions as a scientist to the field of theoretical physics and cosmology.”
Born in South Africa, Turok founded the African Institute for Mathematical Sciences (AIMS) in Cape Town in 2003. AIMS has since expanded to a network of six centres – in South Africa, Senegal, Ghana, Cameroon, Tanzania, and Rwanda – and has become Africa's most renowned institution for postgraduate training in mathematical science. For his scientific discoveries and his work founding and developing AIMS, Turok was awarded a TED Prize in 2008. He has also been recognized with awards from the World Summit on Innovation and Entrepreneurship (WSIE) and the World Innovation Summit on Education (WISE). In 2016 he was named the Gerald Whitrow Lecturer by the Royal Astronomical Society and was also awarded the John Torrence Tate Medal for International Leadership in Physics by the American Institute of Physics. In the same year, he was made an Honorary Fellow of the Institute of Physics in the UK and was awarded the John Wheatley Award from the American Physical Society for his work with AIMS.
1) Understanding how to formulate quantum mechanical theories, specially geometrical theories like general relativity, using real time (Lorentzian) path integrals. Although the path integral is well recognised to provide the most elegant and complete formulation of particle and string theories, gauge theories and gravity, it is an enduring embarrassment that the only rigorous, nonperturbative formulation available relies upon a Wick rotation to Euclidean time. Unfortunately, this prevents one from studying dynamics since quantum pre- and post-selection occurs in real time. Secondly, the Euclidean path integral for gravity fails badly. To study quantum cosmology, one really has to use Lorentzian time. Over the past three years, with my collaborators I have pioneered new techniques - based on Picard-Lefschetz theory - which enable one to do this. We have obtained several exciting results, including a disproof of the Hartle-Hawking proposal. Many applications are in development, including applications to quantum tunneling, the Stueckelberg-Schwinger process, the emergence of time in cosmology. Also on the horizon are new, and more convincing ways of studying the quantum evaporation of black holes, as a semiclassical tunneling process.
2) L. Boyle, K. Finn and I have presented the simplest yet solution to the problem of cosmological dark matter. We noticed that the standard model of particle physics, including the right-handed neutrinos required to explain light neutrino masses, has everything required to explain the dark matter without the need to propose any extra fields or particles. Our basic assumption is that the quantum state of the standard model fields respects CPT symmetry, believed to be one of the most basic symmetries of nature. Imposing a discrete Z_2 symmetry ensures that one of the right handed neutrinos is stable. We additionally demand that its vacuum state be CPT invariant. If the mass of the corresponding particle is around 5 x 10^8 GeVm, we match all observations of cosmological dark matter. We are further developing this picture of a CPT invariant universe to explain cosmological homogeneity and isotropy and to explain the character and strength of the primordial perturbations.
3) S. Gielen, U. Pen and me understood that nonlinearities in the plasma of the very early universe inevitably affect the evolution of primordial inhomogeneities in interesting and unexpected ways. In particular, minimal, scale-invariant and approximately Gaussian perturbations lead to the formation of weak shocks with consequent departures from local thermal equilibrium and emission of gravitational Cherenkov radiation. In the future, probes of primordial gravitational waves could allow us to "see" this signal generated in the first microsecond after the big bang.
4) I am fascinated by the results of detailed measurements of the universe on large scales. The presence of dark energy, as well as the extreme simplicity in the large scale structure, seem to me profound clues which no existing theoretical paradigm adequately explains. They may be pointing towards new physical principles, such as CPT symmetry, and the breakdown of conformal symmetry. I am therefore deeply interested in exploring frameworks within which these phenomena may be studied.