## AustMS2021 plenary profile – Richard Brent

*This is the eighth in a series of interviews with the plenary speakers for the upcoming 65th Annual Meeting of the AustMS.*

- What is your earliest mathematical memory?

It’s hard to be sure, but I do remember being pleasantly surprised to learn that 1 + 2 + … + n = n(n+1)/2 – I don’t recall if I worked it out for myself or not. When a young boy (aged about 6) I used to amuse myself on long car trips by doing mental arithmetic, but maybe that doesn’t count as “mathematics”.

- What made you decide to become a mathematician, and when?

When I went to Uni (Monash, 1964-67) as an undergraduate I was undecided between maths, physics and chemistry, but I found that chemistry was too “ad hoc” and physics too “experimental” for me. Also, Monash had a great maths (and stats) department in those days – people like Gordon Preston, Zvonimir Janko, E. Strzelecki, Terry Speed, etc. So perhaps I decided to become a mathematician around 1966, in my third year at Monash. As a graduate student at Stanford (1968-71), I took courses from some great mathematicians (George Polya (in his eighties), Menahem (Max) Schiffer) but ended up graduating in Computer Science (which also had mathematicians: Forsythe, Golub, Knuth, etc). I then worked at the mathematical end of computer science for many years, and did not get a “real” job as a mathematician until the age of 58, when I became a Federation Fellow in MSI at ANU.

- Name a favourite paper by a contemporary mathematician, and why (or more than one, if you can’t decide).

- Brad Rogers and Terence Tao, “The de Bruijn-Newman constant is non-negative”, Forum of Mathematics, Pi. 8, 2020, e6. https://doi.org/10.1017/fmp.2020.6, arXiv:1801.05914

This paper improved on several earlier papers, and any further improvement would require proving (or disproving) the RiemannHypothesis. (Several other papers by Terry Tao are also amongst my “favourites”.)

- What historical mathematician would you like to be able to talk maths with? What would you ask them?

Bernhard Riemann. I would ask him what he knew (or believed to be true) about the Riemann zeta function, but had not published.

- What result would you like to see in mathematics in the next 10 years?

A proof that P ne NP, or that the Riemann Hypothesis is true, or that the optimal exponent in the complexity of matrix multiplication is strictly greater than two, or […]. One attraction of mathematics is that there is never a shortage of interesting open problems!