Palavra-chave: BIFURCATION

SINGULARITY NON-SMOOTH VECTOR FIELDS CLOSED ORBIT CENTER LIMIT CYCLE AVERAGING NONSMOOTH DYNAMICAL SYSTEMS NORMAL FORM ASYMPTOTIC STABILITY STRUCTURAL STABILITY SHILNIKOV PROBLEM CYCLE VERSAL UNFOLDING DISCONTINUOUS VECTOR FIELD FOLD-FOLD FILIPPOV SYSTEMS LOOP STABILITY FIRST INTEGRAL REFRACTIVE VECTOR FIELD PERIODIC ORBIT DIFFEOMORPHISM VECTOR FIELD REGULARIZATION HAMILTONIAN