MEMBERS SEMINAR | |

Topic: | On some Properties of the Nottingham Group |

Speaker: | Mikhail Ershov |

Affiliation: | IAS |

Date: | Monday, November 7 |

Time/Room: | 4:00pm - 5:00pm/S-101 |

Let F be a finite field. The Nottingham group N(F) is the group of formal power series \{ t(1+a_1 t + a_2 t^2 + ...): a_i \in F \}or, equivalently, the group of wild automorohisms of the local field F((t)). In spite of such a simple definition, the subgroup structure of the Nottingham group remains rather mysterious. In this talk I will discuss why the Nottingham group behaves in many aspects like algebraic groups over local fields but at the same exhibits certain "very nonlinear" features.