Rn. Cruz et Ka. Derezende, CYCLE RANK OF LYAPUNOV GRAPHS AND THE GENERA OF MANIFOLDS, Proceedings of the American Mathematical Society, 126(12), 1998, pp. 3715-3720
We show that the cycle-rank r(L) of a Lyapunov graph L on a manifold M
satisfies: r(L) less than or equal to g(M), where g(M) is the genus o
f M. This generalizes a theorem of Franks. We also show that given any
integer r with 0 less than or equal to r less than or equal to g(M),
r = r(L) for some Lyapunov graph L on M, dim M > 2.