A sharp regularity estimate for the Schrödinger propagator on the sphere

Xianghong Chen, Xuan Thinh Duong, Sanghyuk Lee +1

Let ${\Delta }_{{\mathbb{S}}^n}$ denote the Laplace-Beltrami operator on the $n$-dimensional unit sphere ${\mathbb{S}}^n$. In this paper we show that $$ \| e^{it Δ_{\mathbb S^n}}f \|_{L^4([0, 2π…