Extinction on a seascape

 For  μ 0    and  a0  the steady-steady distribution has natural cutoffs at small and large values

 However, the value of    must be computed self-consistently. Averaging the stochastic equations in the steady state gives

,    leading to

,         and

   

New universality class for extinction, with exponents continously varying with noise

The phase transition has multi-fractal character, with distinct singularities for different moments, e.g.

   

 Demographic noise, however, changes the form of the distribution for y →0 :

  Averaging the stochastic equations in the steady state now leads to

The extinction threshold is now shifted to a finite value  , close to which the mean population vanishes as

Standard mean-field (directed percolation) scaling is restored; with anomalous scaling above a crossover scale.