David Allen Hoffman
David Allen Hoffman is an American mathematician whose research concerns
Technical contributions
In 1973, James Michael and Leon Simon established a Sobolev inequality for functions on submanifolds of Euclidean space, in a form which is adapted to the mean curvature of the submanifold and takes on a special form for minimal submanifolds.[6] One year later, Hoffman and Joel Spruck extended Michael and Simon's work to the setting of functions on immersed submanifolds of Riemannian manifolds.[HS74] Such inequalities are useful for many problems in geometric analysis which deal with some form of prescribed mean curvature.[7][8] As usual for Sobolev inequalities, Hoffman and Spruck were also able to derive new isoperimetric inequalities for submanifolds of Riemannian manifolds.[HS74]
It is well known that there is a wide variety of minimal surfaces in the three-dimensional Euclidean space. Hoffman and William Meeks proved that any minimal surface which is contained in a half-space must fail to be properly immersed.[HM90] That is, there must exist a compact set in Euclidean space which contains a noncompact region of the minimal surface. The proof is a simple application of the maximum principle and unique continuation for minimal surfaces, based on comparison with a family of catenoids. This enhances a result of Meeks, Leon Simon, and Shing-Tung Yau, which states that any two complete and properly immersed minimal surfaces in three-dimensional Euclidean space, if both are nonplanar, either have a point of intersection or are separated from each other by a plane.[9] Hoffman and Meeks' result rules out the latter possibility.
Major publications
References
- ^ "David Hoffman | Mathematics". mathematics.stanford.edu.
- ^ "Costa Surface". minimal.sitehost.iu.edu.
- ^ "Fellows of the American Mathematical Society". American Mathematical Society.
- ^ "Chauvenet Prizes | Mathematical Association of America". www.maa.org.
- ^ "David Hoffman - the Mathematics Genealogy Project".
- Zbl 0256.53006.
- Zbl 0589.53058.
- Zbl 0494.53028.
- Zbl 0521.53007.