  In this paper we obtain some new inhomogeneous Strichartz estimates for the
fractional Schr\"odinger equation in the radial case. Then we apply them to the
well-posedness theory for the equation
$i\partial_{t}u+|\nabla|^{\alpha}u=V(x,t)u$, $1<\alpha<2$, with radial
$\dot{H}^\gamma$ initial data below $L^2$ and radial potentials $V\in
L_t^rL_x^w$ under the scaling-critical range $\alpha/r+n/w=\alpha$.
