INTERMINGLED FRACTAL ARNOLD TONGUES

We present a pattern of multiply interwoven Arnold tongues in the case of the single-well Duffing oscillator at low dissipation and weak for cing: Strips of 2/2 Arnold tongues form a truncated fractal structure and the tonguelike regions in between an filled by finely intermingled fractal-like 1/1 and 3/3 Arnold tongues, which are fat fractals chara cterized by the uncertainty exponent alpha approximate to 0.7. The tru ncated fractal Arnold tongues are present in the case of high dissipat ion as well, while the intermingled fractal pattern gradually disappea rs with increasing dissipation. [S1063-651X(98)04002-1].