5 research outputs found
From a Reeb orbit trap to a Hamiltonian plug
We present a simple construction of a plug for Hamiltonian flows on
hypersurfaces of dimension at least five by doubling a trap for Reeb orbits.Comment: 6 page
Trapped Reeb orbits do not imply periodic ones
We construct a contact form on R^{2n+1}, n at least 2, equal to the standard
contact form outside a compact set and defining the standard contact structure
on all of R^{2n+1}, which has trapped Reeb orbits, including a torus invariant
under the Reeb flow, but no closed Reeb orbits. This answers a question posed
by Helmut Hofer.Comment: 6 page
Isoperimetric Inequalities for Minimal Submanifolds in Riemannian Manifolds: A Counterexample in Higher Codimension
For compact Riemannian manifolds with convex boundary, B.White proved the
following alternative: Either there is an isoperimetric inequality for minimal
hypersurfaces or there exists a closed minimal hypersurface, possibly with a
small singular set. There is the natural question if a similar result is true
for submanifolds of higher codimension. Specifically, B.White asked if the
non-existence of an isoperimetric inequality for k-varifolds implies the
existence of a nonzero, stationary, integral k-varifold. We present examples
showing that this is not true in codimension greater than two. The key step is
the construction of a Riemannian metric on the closed four-dimensional ball B
with the following properties: (1) B has strictly convex boundary. (2) There
exists a complete nonconstant geodesic. (3) There does not exist a closed
geodesic in B.Comment: 11 pages, We changed the title and added a section that exhibits the
relation between our example and the question posed by Brian White concerning
isoperimetric inequalities for minimal submanifold