English

A negative mass theorem for the 2-Torus

Spectral Theory 2009-11-13 v2 Differential Geometry

Abstract

For a closed surface M with metric g, the Robin mass m(p) at the point p is the value of the Green function G(p,q) at p=q after the logarithmic singularity has been removed. The Laplacian-mass is the average value of the Robin mass, minus the value of the Robin mass for the round sphere of the same area. The Laplacian-mass is a spectral invariant which is a natural analog of the ADM mass for asymptotically flat manifolds. We show that if M is a torus, then the minimum value of the Laplacian-mass on the conformal class of g is negative. It is attained by a (smooth) metric for which one gets a sharp logarithmic Hardy-Littlewood-Sobolev inequality and Onofri-type inequality. If the flat metric in the conformal class is sufficiently long and thin, then the minimizer for the Laplacian-mass is non-flat.

Cite

@article{arxiv.0711.3489,
  title  = {A negative mass theorem for the 2-Torus},
  author = {Kate Okikiolu},
  journal= {arXiv preprint arXiv:0711.3489},
  year   = {2009}
}
R2 v1 2026-06-21T09:46:04.168Z