In a
d -dimensional strip with
17ca064e7fd03a42652f873" title="Click to view the MathML source">d≥2, we study the non-stationary Stokes equation with no-slip boundary condition in the lower and upper plates and periodic boundary condition in the horizontal directions. In this paper we establish a new maximal regularity estimate in the real interpolation norm
where the brackets
〈⋅〉 denote the horizontal-space and time average. The norms involved in the definition of
‖⋅‖(0,1) are critical for two reasons: the exponents are borderline for the Calderón–Zygmund theory and the weight
1/z just fails to be Muckenhoupt. Therefore, the estimate is only true under horizontal bandedness condition (i.e. a restriction to a packet of wave numbers in Fourier space). The motivation to express the maximal regularity in such a norm comes from an application to the Rayleigh–Bénard problem (see
[5]).