摘要
In this paper, we give a proof of the radial Glassey conjecture with minimal regularity assumption. In the process, we prove a weighted fractional chain rule, which is of independent interest. We also show well-posedness for 3-D quadratic semi-linear wave equations with radial data in the almost scalecritical Sobolev space, which improves the earlier result of Klainerman and Machedon.