2020/02/17 by Veloso, Jose
#Differential Geometry (math.DG) #FOS: Mathematics
paper · doi:10.48550/arxiv.2002.07177
The authors Balogh-Tyson-Vecchi in arXiv:1604.00180 utilize the Riemannian approximations scheme (\mathbb H1,L), in the Heisenberg group, introduced by Gromov, to calculate the limits of Gaussian and normal curvatures defined on surfaces of \mathbb H1 when L→∞. They show that these limits exist (unlike the limit of Riemannian surface area form or length form), and they obtain Gauss-Bonnet theorem in \mathbb H1 as limit of Gauss-Bonnet theorems in (\mathbb H1,L) when L goes to infinity. This construction was extended by Wang-Wei in arXiv:1912.00302 to the affine group and the group of rigid motions of the Minkowski plane. We generalize constructions of both papers to surfaces in sub-Riemannian three dimensional manifolds following the approach of arXiv:1909.13341, and prove analogous Gauss-Bonnet theorem.