The symplectic representation of the mapping class group is unique
arXiv:1108.3241
Abstract
Any nontrivial homomorphism from the mapping class group of an orientable surface of genus to $\GL(2g,\C)$ is conjugate to the standard symplectic representation. It is also shown that the mapping class group has no faithful linear representation in dimensions less than or equal to .
22 pages, 3 figures