LYAPUNOV ANALYSIS OF SPATIOTEMPORAL INTERMITTENCY

Lyapunov exponents and vectors are investigated for a chain of locally coupled maps known to exhibit a continuous transition to spatio-temporal intermittency regimes. The accompanying critical behaviour (e.g., the divergence of the coherence scales) is not reflected in the behaviour of the largest Lyapunov exponent, which remains constant, but rather in extensive quantities such as the density of exponents close to zero, which is conjectured to diverge at threshold in the infinite-size limit. These results, which differ from those obtained on systems showing more <<spatially distributed>> disorder, stress the essential feature of spatiotemporal intermittency, the localized character of the chaotic activity in the system.