Affine tangles and irreducible exotic sheaves

We construct a weak representation of the category of framed affine tangles on a disjoint union of triangulated categories ${\mathcal{D}}_{2n}$. The categories we use are that of coherent sheaves on Springer fibers over a nilpotent element of $s{l}_{2n}$ with two equal Jordan blocks. This representation allows us to enumerate the irreducible objects in the heart of the exotic $t$-structure on ${\mathcal{D}}_{2n}$ by crossingless matchings of $2n$ points on a circle. We also describe the algebra of endomorphisms of the direct sum of the irreducible objects.