Monthly Seminar on Arithmetic of Automorphic Forms

Seminar information archive ~05/22Next seminarFuture seminars 05/23~

Date, time & place Saturday 13:30 - 16:00 123Room #123 (Graduate School of Math. Sci. Bldg.)

2009/11/14

13:30-16:00   Room #117 (Graduate School of Math. Sci. Bldg.)
岡崎武生 (京都大学) 13:30-14:30
On weak endoscopic lift (117号室)
[ Abstract ]
rank 2のsymplectic 群の保型表現$\\pi$の spinor L-関数(4次)が殆どの素点で楕円保型形式のL-関数の積になっているものをweak ndoscopic liftと呼びます. $\\pi$がtemperedならば, 全てのweak endoscopic liftはrank 4のtheta関数(theta lift)でかける事がBrooks Roberts氏により知られています.
本公演では, このtheta liftの明示的な構成法やその周辺に関する話題(Siegel 三次多様体など)についてお話したいと思います.
井原健太郎 (POSTEC) 15:00-16:00
Derivations and Automorphisms on the noncommutative algebra of power series.


[ Abstract ]
We discuss a relationship between a class of derivations and a class of automorphisms on the noncommutative algebra of formal power series in two variables. Each class relates bijectively by exponential and logarithm maps. In this talk we define a specific class of derivations, which generates a noncommutaive Lie algebra whose defining relations are related to a classical Witt algebra. The main claim is the explicit description of the
automorphisms which are corresponding to the derivations via exponential map.