本文印刷
全画面プリント
トポロジー火曜セミナー
過去の記録 ～06/25｜次回の予定｜今後の予定 06/26～
| 開催情報 | 火曜日 17:00～18:30 数理科学研究科棟(駒場) 056号室 |
|---|---|
| 担当者 | 河澄 響矢, 北山 貴裕, 逆井卓也, 葉廣和夫 |
| セミナーURL | https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index.html |
2019年01月08日(火)
17:00-18:30 数理科学研究科棟(駒場) 056号室
Tea: Common Room 16:30-17:00
Marek Kaluba 氏 (Adam Mickiewicz Univeristy)
On property (T) for Aut(Fn) and SLn(Z) (ENGLISH)
Tea: Common Room 16:30-17:00
Marek Kaluba 氏 (Adam Mickiewicz Univeristy)
On property (T) for Aut(Fn) and SLn(Z) (ENGLISH)
[ 講演概要 ]
We prove that Aut(Fn) has Kazhdan's property (T) for every n≥6. Together with a previous result of Kaluba, Nowak, and Ozawa, this gives the same statement for n≥5. We also provide explicit lower bounds for the Kazhdan constants of SAut(Fn) (with n≥6) and of SLn(Z) (with n≥3) with respect to natural generating sets. In the latter case, these bounds improve upon previously known lower bounds whenever n>6.
We prove that Aut(Fn) has Kazhdan's property (T) for every n≥6. Together with a previous result of Kaluba, Nowak, and Ozawa, this gives the same statement for n≥5. We also provide explicit lower bounds for the Kazhdan constants of SAut(Fn) (with n≥6) and of SLn(Z) (with n≥3) with respect to natural generating sets. In the latter case, these bounds improve upon previously known lower bounds whenever n>6.
