Results on infinite-dimensional topology and applications to the structure of the critical set of nonlinear Sturm–Liouville operators

<i>Theory of Ordinary Differential Equations</i>

Earl A. Coddington, Norman Levinson, T. Teichmann · Physics Today · 1956 · 6.3K citations

Natural Sciences, Mathematics, Differential Equations +6

Theory of ordinary differential equations

H.L. Platzer · Journal of the Franklin Institute · 1956 · 5.7K citations

Natural Sciences, Mathematics, Differential Equations +7

On the inversion of some differentiable mappings with singularities between Banach spaces

Antonio Ambrosetti, G. A. Prodi · Annali di Matematica Pura ed Applicata (1923 -) · 1972 · 440 citations · Full text

Natural Sciences, Mathematics, Topology +11

The homotopy type of the unitary group of Hilbert space

Nicolaas H. Kuiper · Topology · 1965 · 409 citations

Natural Sciences, Mathematics, Physics +14

Hilbert Manifolds

Dan Burghelea, Nicolaas H. Kuiper · Annals of Mathematics · 1969 · 33 citations