# Multilinear singular integrals on non-commutative $L^p$ spaces

## TL;DR

This paper establishes $L^p$ bounds for multilinear Calderón-Zygmund operators on non-commutative $L^p$ spaces, broadening the scope of such bounds without requiring additional assumptions like the Rademacher maximal function property.

## Contribution

It extends multilinear singular integral bounds to non-commutative $L^p$ spaces using minimal assumptions, enabling new applications such as fractional Leibniz rules.

## Key findings

- Proved $L^p$ bounds for multilinear operators on non-commutative spaces.
- Showed Rademacher maximal function property is unnecessary for these bounds.
- Applied results to derive new fractional Leibniz rules.

## Abstract

We prove $L^p$ bounds for the extensions of standard multilinear Calder\'on-Zygmund operators to tuples of UMD spaces tied by a natural product structure. This can, for instance, mean the pointwise product in UMD function lattices, or the composition of operators in the Schatten-von Neumann subclass of the algebra of bounded operators on a Hilbert space. We do not require additional assumptions beyond UMD on each space - in contrast to previous results, we e.g. show that the Rademacher maximal function property is not necessary. The obtained generality allows for novel applications. For instance, we prove new versions of fractional Leibniz rules via our results concerning the boundedness of multilinear singular integrals in non-commutative $L^p$ spaces. Our proof techniques combine a novel scheme of induction on the multilinearity index with dyadic-probabilistic techniques in the UMD space setting.