English

On Area Growth in Sol

Differential Geometry 2021-01-14 v3

Abstract

Let Sol be the 33-dimensional solvable Lie group whose underlying space is R3\mathbb{R}^3 and whose left-invariant Riemannian metric is given by e2zdx2+e2zdy2+dz2.e^{-2z} dx^2 + e^{2z} dy^2 + dz^2. Building on previous joint work with Matei Coiculescu, which characterizes the cut locus in Sol, we prove that the sphere of radius r in sol has area at most 20πer20 \pi e^r provided that r is sufficiently large. This estimate is sharp up to a factor of 10

Cite

@article{arxiv.2004.10622,
  title  = {On Area Growth in Sol},
  author = {Richard Evan Schwartz},
  journal= {arXiv preprint arXiv:2004.10622},
  year   = {2021}
}

Comments

The previous version of the paper had a bound of $611 e^r$. In this version, I improve the constant from $611$ to $20 \pi$. This is an order of magnitude better. The proof is essentially the same. I am just more careful with the estimates in a few places

R2 v1 2026-06-23T15:01:44.456Z