# MAA

## Seminar

### Measurable structures, and asymptotics in finite structures

Macpherson, D (Leeds)
Thursday 23 June 2005, 15:30-17:00

Seminar Room 1, Newton Institute

#### Abstract

Work of Chatzidakis, van den Dries and Macintyre [CDM] shows that in finite fields, the sizes of definable sets (defined by a fixed formula with parameters) have a uniform asymptotic behaviour as the field and parameters vary. This enables one to associate a dimension (the natural one) and a measure to any definable set in a pseudofinite field. I and Steinhorn have investigated arbitrary classes of finite structures for which the conclusion of the [CDM] theorem holds, and the corresponding notion of (supersimple) measurable structure. In this talk I will describe examples, but will mainly discuss more recent work of Ivan Tomasic, Richard Elwes, and Mark Ryten.