Let A be an algebra over a commutative ring k. We prove that braidings on the category of A-bimodules are in bijective correspondence to canonical R-matrices, these are elements in A⊗A⊗A satisfying certain axioms. We show that all braidings are symmetries. If A is commutative, then there exists a braiding on AMA if and only if k → A is an epimorphism in the category of rings, and then the corre...

‎The Mod $2$ Steenrod algebra is a Hopf algebra that consists of the primary cohomology operations‎, ‎denoted by $Sq^n$‎, ‎between the cohomology groups with $mathbb{Z}_2$ coefficients of any topological space‎. ‎Regarding to its vector space structure over $mathbb{Z}_2$‎, ‎it has many base systems and some of the base systems can also be restricted to its sub algebras‎. ‎On the contrary‎, ‎in ...

The dynamics of an ideal fluid or plasma is constrained by topological invariants such as the circulation of (canonical) momentum. In the Hamiltonian formalism, topological invariants restrict the orbits to submanifolds of the phase space. While the coadjoint orbits have a natural symplectic structure, the global geometry of the degenerate (constrained) Poisson manifold can be very complex. Som...

We study McKay’s observation on the Monster simple group, which relates the 2A-involutions of the Monster simple group to the extended E8 diagram, using the theory of vertex operator algebras (VOAs). We first consider the sublattices L of the E8 lattice obtained by removing one node from the extended E8 diagram at each time. We then construct a certain coset (or commutant) subalgebra U associat...

We establish the existence of an IC basis for the generalized Temperley{ Lieb algebra associated to a Coxeter system of arbitrary type. We determine this basis explicitly in the case where the Coxeter system is simply laced and the algebra is nite dimensional.

In this paper we construct canonical bases for the Birman-Wenzl algebra BWn, the q-analogue of the Brauer centralizer algebra, and so define left, right and two-sided cells. We describe these objects combinatorially (generalizing the Robinson-Schensted algorithm for the symmetric group) and show that each left cell carries an irreducible representation of BWn. In particular, we obtain canonical...