Hardy-Littlewood maximal function
= Hardy-Littlewood maximal function
{c}
{title2=$Mf$}
{wiki=Hardy–Littlewood_maximal_function}
The centered Hardy-Littlewood maximal function on the real line is
$$
Mf(x)=\sup_{r>0}\frac1{2r}\int_{x-r}^{x+r}|f(t)|\,dt.
$$