$L^p$-valued stochastic convolution integral driven by Volterra noise

Space-time regularity of linear stochastic partial differential equations is studied. The solution is defined in the mild sense in the state space $L^p$. The corresponding regularity is obtained by showing that the stochastic convolution integrals are H\"{o}lder continuous in a suitable function space. In particular cases, this allows to show space-time H\"{o}lder continuity of the solution. The main tool used is a hypercontractivity result on Banach-space valued random variables in a finite Wiener chaos.