Critical exponents from the effective average action

We compute the critical behaviour of three-dimensional scalar theories using a new exact non-perturbative evolution equation. Our values for the critical exponents and other universal constants agree well with previous precision estimates. The evolution equation describes the scale dependence of the effective average action (coarse-grained effective action). It is not restricted to critical phenomena and can be used in the presence of massless (Goldstone) modes dealing successfully with the infrared problems. Our results establish the viability of our method for precise computations in a non-perturbative context. ((orig.))