Nonlinear stiffness, Lyapunov exponents, and attractor dimension

I propose that stiffness may be defined and quantified for nonlinear systems using Lyapunov exponents, and demonstrate the relationship that exists between stiffness and the fractal dimension of a strange attractor: that stiff chaos is thin chaos.Comment: See home page http://lec.ugr.es/~julya

Lyapunov Exponents without Rescaling and Reorthogonalization

We present a new method for the computation of Lyapunov exponents utilizing representations of orthogonal matrices applied to decompositions of M or MM_trans where M is the tangent map. This method uses a minimal set of variables, does not require renormalization or reorthogonalization, can be used to efficiently compute partial Lyapunov spectra, and does not break down when the Lyapunov spectrum is degenerate.Comment: 4 pages, no figures, uses RevTeX plus macro (included). Phys. Rev. Lett. (in press