# Number theory and the circle packings of Appolonius

**Professor Peter Sarnak , School of Mathematics, Institute of Advanced Studies, Princeton, USA**

Like many problems in number theory, the questions that arise from packing the plane with mutually tangent circles are easy to formulate but difficult to answer. Prof Peter Sarnak, from the Institute of Advanced Studies at Princeton, will explain the fundamental features of such packings and how modern tools from number theory, algebra and combinatorics are being used to answer some of these old questions.

- Time: 6:00pm to 7:00pm, Tuesday the 23rd of August
- Venue: The Physiology Lecture Theatres (building 63), room 348, The University of Queensland.
- Arrangments: No need to book – just show up!
- Refreshments: There will be complimentary drinks and nibblies following the talk, where Prof. Peter Sarnak will be available to answer any questions

Professor Peter Sarnak grew up in South Africa and moved to the US to study at Stanford University, where he obtained his PhD in mathematics in 1980. After appointments at the Courant Institute, New York, and Stanford, he moved to Princeton in 1991 where he has been ever since. Currently he is both the Eugene Higgins Professor of Mathematics at Princeton University and Professor at the the Institute for Advanced Study in Princeton. In 2002, he was made a member of the National Academy of Sciences in the USA and a Fellow of the Royal Society.

Peter Sarnak is a major figure in modern analytic number theory, with research interests also in analysis and mathematical physics. He has received many awards for his research including the Polya prize in 1998, the Ostrowski prize in 2001, the Conant prize in 2003 and the Cole prize in 2005. He has had 43 PhD students to date, including several who have become major figures in number theory themselves.

*The Mahler lectures are a biennialactivity organised by the Australian Mathematical Society with the assistance of the Australian Mathematical Sciences Institute.*