Frequency map analysis of the 3/1 resonance between planets b and c in the 55 Cancri system

We investigate the dynamical stability of the 3/1 resonant planets b and c in the extrasolar planetary system around 55 Cancri by applying Laskar's frequency map analysis. We find that the region with low diffusion speed extends to high eccentricity for both planets and that the observed system is deeply embedded in this region. The dynamics while in resonance and the influence of planet e on the resonant couple are also analysed. Using a simple model for the capture of the planets in resonance during migration we show that evolutionary tracks from smaller to the presently observed eccentricities lie in the stable region.