Rotating accelerator-mode islands.

The existence of rotating accelerator-mode islands (RAIs), performing quasiregular motion in rotational resonances of order m > 1 of the standard map, is firmly established by an accurate numerical analysis of all the known data. It is found that many accelerator-mode islands for relatively small nonintegrability parameter K are RAIs visiting resonances of different orders m < or = 3. For sufficiently large K, one finds also "pure" RAIs visiting only resonances of the same order, m = 2 or m = 3. RAIs, even quite small ones, are shown to exhibit sufficient stickiness to produce an anomalous chaotic transport. The RAIs are basically different in nature from accelerator-mode islands in resonances of the "forced" standard map which was extensively studied recently in the context of quantum accelerator modes.