Biography
Elon Lages Lima, Brazilian mathematician (Maceió 09 July 1929 – Rio de Janeiro 07 May 2017)
In his Doctoral thesis Duality and Postnikov invariants (1958) introduced the notion of topological space spectrum, receiving comments in History of Algebraic Topology from Jean Dieudonné
Introduced the category Sp of spectra (1958)
Showed that every pair of commuting vector fields on all compact 2-manifolds with non-vanishing Euler characteristic has a common singularity (1963)
Enunciated Lima theorem
Common singularities of commuting vector fields on 2-manifolds. Comment. Math. Helvet. 39:97-110, 1964.
Proved that a complete hypersurface of Euclidean space is a border of a convex body (with M.P. do Carmo and independent of Sacksteder)
Proved the Jordan-Brouwer separation theorem for equilibrium compact manifolds (1988)