Multiplicity results for nonlinear elliptic equations
A multisymplectic 3-structure on an -dimensional manifold is given by a closed smooth 3-form of maximal rank on which is of the same algebraic type at each point of , i.e. they belong to the same orbit under the action of the group . This means that for each point the form is isomorphic to a chosen canonical 3-form on . R. Westwick [Linear Multilinear Algebra 10, 183–204 (1981; Zbl 0464.15001)] and D. Ž. Djoković [Linear Multilinear Algebra 13, 3–39 (1983; Zbl 0515.15011)] obtained...
We give a survey of the joint papers of Lawrence Somer and Michal Křížek and discuss the beginning of this collaboration.