Dynamical properties of laser models based on the Maxwell Bloch equation are studied. Instances of stability and chaotic behavior are investigated. Special solutions of the system one of which reduces to the Lotka Volterra system under simplifying assumptions are derived. Reasons for the absence of oscillating solutions in the modified systems are studied.

The Hofstadter -sequence and the Hofstadter-Conway $10000 sequence are perhaps the two best known examples of metaFibonacci sequences. In this paper, we explore an unexpected connection between them. When the -sequence is subtracted from the Conway sequence, a chaotic pattern of heart-shaped figures emerges. We use techniques of Pinn and Tanny et al. to explore this sequence. Then, we introduce and analyze an apparent relative of the -sequence and illustrate how it also generates heart patterns when subtracted from the Conway sequence.

No abstract

In this paper we identify weak foci and centers in the Maxwell-Bloch system, a three dimensional quadratic system whose three equilibria are all possible to be of centerfocus type. Applying irreducible decomposition and the isolation of real roots in computation of algebraic varieties of Lyapunov quantities on an approximated center manifold, we prove that at most 6 limit cycles arise from Hopf bifurcations and give conditions for exact number of limit cycles near each weak focus. Further, applying algorithms of computational commutative algebra we find Darboux polynomials and give some center manifolds in closed form globally, on which we identify equilibria to be centers or singular centers by integrability and time-reversibility on a center manifold. We prove that those centers are of at most second order.