Endpoint Differentiability Moduli for Fully Nonlinear Elliptic Equations

A classical consequence of Caffarelli's fully nonlinear regularity theory [L. A. Caffarelli, Ann. of Math. (2) 130 (1989), no. 1, 189-213] is that viscosity solutions of uniformly elliptic equations $F(D^2u)=f$, with $f\in L^p$, $p > n$, are locally $C^{1,γ}$ for every $γ< \min\{α_H,σ_p\}$. Here $α_