Exploring a modification of dp convergence

Abstract

In the work by M. C. Lee, A. Naber, and R. Neumayer (Lee et al., 2023) a beautiful $\varepsilon$-regularity theorem is proved under small negative scalar curvature and entropy bounds. In that paper, the $d_p$ distance for Riemannian manifolds is introduced and the quantitative stability results are given in terms of this notion of distance, with important examples showing why other existing notions of convergence are not adequate in their setting. Due to the presence of an entropy bound, the possibility of long, thin splines forming along a sequence of Riemannian manifolds whose scalar curvature is becoming almost positive is ruled out. It is important to rule out such examples since the $d_p$ distance is not well behaved in the presences of splines that persist in the limit. Since there are many geometric stability conjectures (Gromov, 2023; Sormani, 2023) where we want to allow for the presence of splines that persist in the limit, it is crucial to be able to modify the $d_p$ distance to retain its positive qualities and prevent it from being sensitive to splines. In this paper we explore one such modification of the $d_p$ distance and give a theorem which allows one to estimate the modified $d_p$ distance, which we expect to be useful in practice.