  We study dissipative dynamics constructed by means of non-commutative
Dirichlet forms for various lattice systems with multiparticle interactions
associated to CCR algebras. We give a number of explicit examples of such
models. Using an idea of quasi-invariance of a state, we show how one can
construct unitary representations of various groups. Moreover in models with
locally conserved quantities associated to an infinite lattice we show that
there is no spectral gap and the corresponding dissipative dynamics decay to
equilibrium polynomially in time.
