Quantitative index bounds for translators via topology
Abstract
We obtain a quantitative estimate on the generalised index of translators for the mean curvature flow with bounded norm of the second fundamental form. The estimate involves the dimension of the space of weighted square integrable f-harmonic 1-forms. By the adaptation to the weighted setting of Li-Tam theory developed in previous works, this yields estimates in terms of the number of ends of the hypersurface when this is contained in a upper halfspace with respect to the translating direction. When there exists a point where all principal curvatures are distinct we estimate the nullity of the stability operator. This permits to obtain quantitative estimates on the stability index via the topology of translators with bounded norm of the second fundamental form which are either two-dimensional or (in higher dimension) have finite topological type and are contained in a upper halfspace.
Cite
@article{arxiv.1804.07709,
title = {Quantitative index bounds for translators via topology},
author = {Debora Impera and Michele Rimoldi},
journal= {arXiv preprint arXiv:1804.07709},
year = {2019}
}
Comments
14 pages. Translators seem to support a weighted L^2 Sobolev inequality only in dimension greater than or equal to 3 and when the translator is contained in a upper halfspace with respect to the translating direction; see Appendix A. Statements of Theorem A, Theorem B, Corollary C and Theorem E fixed accordingly. Theorem D still holds unchanged. Final version: to appear on Math. Z