I just asked if the following inequality is correct ?
${\parallel f\parallel}_{{L}_{p}} \leq c {\parallel f\parallel}_{{L}_{2}} $
Where ${L}^{p}$ is the space of periodic real functions on a bounded set $Q$ ,such that $Q$$\subset $ ${R}^{3}$ with $0<p<1$ .
I am loking for a reference to the ${L}^{p}$ spaces with $0<p<1$ ? . Thanks.