代数幾何学セミナー:Minimal Salem numbers on supersingular K3 surfaces

開催日時
2016年   12月 2日 10時 30分 ~ 2016年   12時 00分
場所
理学部3号館210室
講演者
Simon Brandhorst (Universities Hannover)
 
講演概要 : The entropy of a surface automorphism is either zero or the logarithm of a Salem number, that is an algebraic integer $\lambda>1$ which is conjugate to $1/\lambda$ and all whose other conjugates lie on the unit circle. In the case of a complex K3 surface McMullen gave a strategy to decide whether a given Salem number arises in this way. It combines methods from linear programming, number fields, lattice theory and the Torelli theorems. In this talk we extend these methods to automorphisms of supersingular K3 surfaces using the crystalline Torelli theorems and apply them in the case of characteristic $5$.
This is joint work with Víctor González Alonso.

関連項目

研究集会・セミナー・集中講義の一覧へ