分野別セミナー

This is a joint work with T. Ikeda.
Although covering groups are not algebraic group, phoenomena analogous to the endoscopy had been found for the covering groups.
In this talk, I will explain endoscopies for covering groups of SL_2.
For some cases we succeeded to construct covering groups of quaternion algebra.
In this talk, I will also explain the functoriality for such covering groups of inner forms of SL_2 and GL_2.