Irreducible complexity of iterated symmetric bimodal maps

We introduce a tree structure for the iterates of symmetric bimodal maps and identify a subset which we prove to be isomorphic to the family of unimodal maps. This subset is used as a second factor for a $\ast$-product that we define in the space of bimodal kneading sequences. Finally, we give some properties for this product and study the *-product induced on the associated Markov shifts

Projectile motion: the "coming and going" phenomenon

An interesting phenomenon that occurs in projectile motion, the "coming and going", is analyzed considering linear air resistance force. By performing both approximate and numerical analysis, it is showed how a determined critical angle and an interesting geometrical property of projectiles can change due to variation on the linear air resistance coefficient

A Growth model for DNA evolution

A simple growth model for DNA evolution is introduced which is analytically solvable and reproduces the observed statistical behavior of real sequences.Comment: To be published in Europhysics Letter

Black Holes in 2+1 Teleparallel Theories of Gravity

We apply the Hamiltonian formulation of teleparallel theories of gravity in 2+1 dimensions to a circularly symmetric geometry. We find a family of one-parameter black hole solutions. The BTZ solution fixes the unique free parameter of the theory. The resulting field equations coincide with the teleparallel equivalent of Einstein's three-dimensional equations. We calculate the gravitational energy of the black holes by means of the simple expression that arises in the Hamiltonian formulation and conclude that the resulting value is identical to that calculated by means of the Brown-York method.Comment: 20 pages, Latex file, no figure

Nonuniversality of weak synchronization in chaotic systems

We show that the separate properties of weak synchronization (WS) and strong synchronization (SS), reported recently by Pyragas [K. Pyragas, Phys. Rev. E, 54, R4508 (1996)], in unidirectionally coupled chaotic systems, are not generally distinct properties of such systems. In particular, we find analytically for the tent map and numerically for some parameters of the circle map that the transition to WS and SS coincide.Comment: 3 pages (Revtex) and 3 figures (postscript) To appear in Phys. Rev. E (Rapid Communications

K-theory for Cuntz-Krieger algebras arising from real quadratic maps

We compute the $K$-groups for the Cuntz-Krieger algebras $\mathcal{O}_{A_{\mathcal{K}(f_{\mu})}}$, where $A_{\mathcal{K}(f_{\mu})}$ is the Markov transition matrix arising from the \textit{kneading sequence }$\mathcal{K} (f_{\mu})$ of the one-parameter family of real quadratic maps $f_{\mu}$.Comment: 8 page