A strictly convex Sobolev function with null Hessian minors

Convexity conditions and existence theorems in nonlinear elasticity

J. M. Ball · Archive for Rational Mechanics and Analysis · 1976 · 2.4K citations

Convexity Conditions, Nonlinear Elasticity, Variational Inequality +2

C 1 Isometric Imbeddings

John C. Nash · Annals of Mathematics · 1954 · 417 citations

Integral Geometry, Engineering, Manifold Learning +3

Null Lagrangians, weak continuity, and variational problems of arbitrary order

J. M. Ball, J. C. Currie, Peter J. Olver · Journal of Functional Analysis · 1981 · 319 citations

Null Lagrangians, Variational Analysis, Functional Analysis +4

On C1-isometric imbeddings. I

Nicolaas H. Kuiper · Indagationes Mathematicae (Proceedings) · 1955 · 300 citations

Integral Geometry, Engineering, Interpolation Space +3

On Spherical Image Maps Whose Jacobians Do Not Change Sign

Philip Hartman, Louis Nirenberg · American Journal of Mathematics · 1959 · 265 citations

Integral Geometry, Global Analysis, Change Sign +1