Expansion-modificaction systems: an explanation for long range correlations in DNA

Based on a model first studied in [Physical Review A, vol. 43, 5240-5260,1991] properties of correlation function for expansion-modification systems are developed. The existence of several characteristic exponents is proved. The relationship of this fact with long-range correlation in DNA is stablished. Comparison between theoretical exponents and those obtained from simulation and real sequences are also showed.