Thermodynamical behavior of aperiodic Ising models on hierarchical lattices

This work brings an analysis of the behavior of Ising spins on a hierarchic al lattice subject to relevant fluctuations on the coupling constants that are induced by a deterministic aperiodic sequence. The thermodynamical func tions are evaluated after the numerical iteration of a set of coupled maps, obtained within the method of transfer matrices. The typical specific heat cusp of the homogeneous system is destroyed by the fluctuations, which als o cause changes in the values of all critical exponents. [S1063-651X(99)030 01-9].