The Schwarz lemma at the boundary of the symmetrized bidisc

The symmetrized bidisc G2 is defined byG2:={(z1+z2,z1z2)∈C2:|z1|<1,|z2|<1,z1,z2∈C}. It is a bounded inhomogeneous pseudoconvex domain without C1 boundary, and especially the symmetrized bidisc hasn't any strongly pseudoconvex boundary point and the boundary behavior of both Carathéodory and Kobayashi metrics over the symmetrized bidisc is hard to describe precisely. In this paper, we study the boundary Schwarz lemma for holomorphic self-mappings of the symmetrized bidisc G2, and our boundary Schwarz lemma in the paper differs greatly from the earlier related results.