Some More Sparse Bounds for Rough and Smooth Pseudodifferential Operators

Abstract

Beltran \& Cladek~\cite{BC} use $L^r$ to $L^s$ bounds to prove sparse form bounds for pseudodifferential operators with Hörmander symbols in $S_{\ddot{I},\hat{I}´}^m$ up to, but not including, the sharp end-point in decay $m$. We further develop their technique, obtaining pointwise sparse bounds for rough pseudodifferential operators that are merely measurable in their spatial variables and an alternative proof of their results which avoids proving geometrically decaying sparse bounds. We also provide sufficient conditions for sparse form bounds to hold and use these to reprove know sparse bounds for pseudodifferential operators with symbols in $S_{1,\hat{I}´}^0$ for $\hat{I}´<1$.

23 pages. Definitions have been moved to the introduction. What was Proposition 1.5 is now Proposition 2.2. It has been modified slightly in order to be applied (in what is now Theorem 4.3) in a manner more relevant to the rest of the paper, and so the previous application (which was Theorem 1.6) has been removed. The new sharp function bounds are now contained in Theorem 1.10