Symplectic Group

If for , we can realize a symplectic form by defining for being the almost complex structure. The symplectic group associated to this form is then defined as More generally, we write for all symplectic operators .

In fact, linear symplectic spaces of the same dimension are unique up to symplectomorphism, that is, an isomorphism that preserves the symplectic form. For details on why this is the case, see proposition.