Showing math.DSShow all
2 papers · 1 filter
math.DS2019
Hilbert's 16th problem. II. Pfaffian equations and variational methods
Pablo Pedregal
Starting from a Pfaffian equation in dimension and focusing on compact solutions for it, we place in perspective the variational method used in [29] to solve Hilbert's 16th pro…
math.DS2019
Hilbert's 16th problem. I. When differential systems meet variational methods
Jaume Llibre, Pablo Pedregal
We provide an upper bound for the number of limit cycles that planar polynomial differential systems of a given degree may have. The bound turns out to be a polynomial of degree fo…