Symmetry breaking and the twisted elastic ring

Symmetry breaking is considered in the context of a parameter-dependent two -point boundary value problem describing a twisted elastic ring that arises as a model of DNA minicircles. We explicitly determine, via a perturbation expansion, those representatives of a manifold of solutions to a symmetric BVP that persist when the symmetry is broken. Conditions generating a gene ric splitting are identified, and some degenerate cases are studied. In bot h the generic and degenerate cases, the results of the perturbation expansi on are used to improve the efficiency of existing algorithms for computing symmetry-broken bifurcation diagrams. (C) 1998 Elsevier Science S.A. All ri ghts reserved.