New class of eigenstates in generic Hamiltonian systems

In mixed systems, besides regular and chaotic states, there are stares supp orted by the chaotic region mainly living in the vicinity of the hierarchy of regular islands. We show that the fraction of these hierarchical states scales as h(alpha) and we relate the exponent alpha = 1 - 1/gamma to the de cay of the classical staying probability P(t) similar to t(-gamma). This is numerically confirmed for the kicked rotor by studying the influence of hi erarchical states on eigenfunction and level statistics.