Fig 4. Dependence on g of the stable equilibrium behind the wave front, where s = ξ × g is assumed to covary with g.

Fixed parameter values are a = 1, b = 1, w = 0.5, p = 0.7, q = 0.2, and ξ = 1/15. Grey dots give the numerically-simulated normalized values of $\widehat{F}$ for each value of w. Similarly, black dots connected by broken and solid lines give the values of $\widehat{C}$ and $\widehat{H}$, respectively. The brown dots give the numerically obtained speeds. Note the relevant equilibrium behind the wave front is E5 when g < 1 − q = 0.8 and E3 when the inequality is reversed. The heuristically predicted speed is always $v=2\sqrt{a(1-w)}$, because 1 + s − p < a(1 − w) for the range of values of s (Appendix 3). For E5, $\widehat{F}$ is monotone increasing in g because ξ<w(p−w)/(1−wq) = 1/9, $\widehat{C}$ is monotone increasing in g, and $\widehat{H}$ is monotone decreasing in g.