Fefferman's SAK principle in one dimension
Fefferman's SAK principle in one dimension
In this article we give a complete proof in one dimension of an a priori inequality involving pseudo-differential operators: if a and b are symbols in S 1,0 2 such that |a|≤b, then for all ϵ>0 we have the estimate ∥a w u∥ s 2 ≤C ϵ (∥b w u∥ …