Maximal Tracial Algebras

We introduce and study the notion of maximal tracial algebras. We prove several results in a general setting based on dual pairs and multiplier pairs. In a special case that X is a Banach space we determine the abelian subalgebras of B(X) that are maximal tracial for rank-one tensors. We also make slight connections between our ideas and the Kadison Similarity Problem and also the Connes' Embedding Problem.