A simple sufficient condition for the coexistence of quantum effects

TL;DR

This paper introduces a new, simple sufficient condition that unifies commutativity and comparability, broadening the criteria for when two quantum effects can be measured together.

Contribution

It proposes a unified condition that is simpler and more widely applicable for the coexistence of quantum effects compared to previous criteria.

Findings

The new condition encompasses previous sufficient conditions.

It simplifies the criteria for quantum effects coexistence.

The condition is more broadly applicable than earlier known conditions.

Abstract

Two quantum effects are considered coexistent if they can be measured together. It is known that commutativity and comparability are sufficient but not necessary for the coexistence of two effects. We unify those two conditions to a simple but more widely applicable sufficient condition.