In the Blair, Smith and Sogge's paper Strichartz estimates for the wave equation on manifolds with boundary, the authors study integrability estimates for solution of the following problem:

\begin{equation} \partial_t^2 u(t,x)-\Delta_g u(t,x)=0, ~ u(0,x)=f(x), ~ \partial_tu(0,x)=g(x) \tag{1.1} \end{equation} where $\Delta_g$ denotes the Laplace–Beltrami operator on $(M,g)$ with $(M, g)$ a Riemannian manifold of dimension $n \geq 2$.

They establish the following result:

**Theorem 1.1.** Let $M$ be a compact Riemannian manifold with boundary. Suppose $2<p\leq \infty$, $2 \leq q < \infty$ and $(p,q,\gamma)$ is a triple satisfying
\begin{equation}
\frac{1}{q} + \frac{n}{q}= \frac{n}{2}-\gamma \hspace{ 2cm}\begin{cases}
\frac{3}{p}+\frac{n-1}{q} \leq \frac{n-1}{2}, n \leq 4 \\
\frac{1}{p}+\frac{1}{q} \leq \frac{1}{2}, n \geq 4
\end{cases}
\end{equation}
Then we have the following estimates for solutions $u$ to (1.1) satisfying either Dirichlet or Neumann homogeneous boundary conditions
\begin{equation} \|u\|_{L^{p}([-T,T];L^q(M))}\leq C(\|f\|_{H^{\gamma}(M)}+\|g\|_{H^{\gamma-1}(M)})\end{equation}
with $C$ some constant depending on $M$ and $T$.

As a corollary we have the following result:

**Corollary 1.2.** Let $M$ be a compact Riemannian manifold with boundary. Suppose that the triples $(p,q,\gamma)$ and $(r',s',1-\gamma)$ satisfy the condition of Theorem 1.1 Then we have the following estimate for solutions $u$ to (1.1) satisfy either Dirichlet or Neumann homogeneous boundary condition
\begin{equation} \|u\|_{L^{p}([-T,T];L^q(M))}\leq C(\|f\|_{H^{\gamma}(M)}+\|g\|_{H^{\gamma-1}(M)}+\|F\|_{L^r([-T,T];L^s(M))})\end{equation}
with $C$ some constant depending on $M$ and $T$.

It is easy to see that the triple $(r',s',1-\gamma)=(\infty,2,1-1)=(\infty,2,0)$ is in the conditions of the Corollary 1.2. so we have the estimate: \begin{equation} \|u\|_{L^{p}([-T,T];L^q(M))}\leq C(\|f\|_{H^{1}(M)}+\|g\|_{L^2(M)}+\|F\|_{L^1([-T,T];L^2(M))}) \tag{*}\end{equation} for solutions of problem $(1.1)$.

My question:

I would like to know if there is an estimate similar to $(*)$ but with $F \in L^1([-T;T]; H^{-1}(M)).$