Achiral and chiral involutive categories

Robin Cockett

University of Calgary




Abstract: A (contravariant) involutive category is a category equipped with an equivalence to its dual: it is achiral in case the two adjoints are exactly the same and, furthermore, the counit and unit are the same. It is a chiral involutive category when the two adjoints are distinct. From such an achiral category one can construct a "unitary" involutive category. These can be alternately viewed as involutive categories with an inner product and (using the inner product structure) they can be shown to be canonically equivalent to dagger categories.

We shall discuss the question of what the appropriate functors are between general chiral involutive categories. Following Paul-Andre Mellies, we shall argue that his symmetry breaking chiral functors fulfill this role. Given time, we shall discuss how these functors give rise to dagger linearly distributive categories ($\dagger$-LDC). These were used by Priyaa Srinivasan in her PhD. to support an interpretation of infinite dimensional quantum mechanics. The talk, therefore, provides an alternative mathematical provenance to explain mathematically how $\dagger$-LDCs arise.

This is joint work with Priyaa and Durgesh.