Sharp $L^{p}-L^{q}$ estimates for the spherical harmonic projection (Harmonic Analysis and Nonlinear Partial Differential Equations)
Yehyun Kwon, Sanghyuk Lee · Institutional Repositories DataBase (IRDB) · 2018
We consider Lp-Lq estimates for the spherical harmonic projection operators and obtain sharp bounds on a certain range of p, q. As an application, we provide a proof of off-diagonal Carleman estimates for the Laplacian, which extends the earlier results due to Jerison and Kenig [22], and Stein [34].