Bifurcation of One{dimensional Stochastic Diierential Equation

We consider families of random dynamical systems induced by parametrized one dimensional stochastic diierential equations. We give necessary and suucient conditions on the invariant measures of the associated Markov semigroups which ensure a stochastic bifurcation. This leads to suucient conditions on drift and diiusion coeecients for a stochastic pitchfork and transcritical bifurcation of the family of random dynamical systems.