= Parity splitting of a mean-field dynamo threshold
An antisymmetric perturbation can split the thresholds of two degenerate <mean-field dynamo> parity classes. At first order, project the perturbation equation onto the adjoint null mode using the <Fredholm alternative>. If multiplying the unperturbed complex mode by $i$ leaves the parameter-derivative matrix element unchanged but reverses the perturbation matrix element, the two first-order threshold shifts are equal and opposite.
Back to article page
