The q-AGT-W relations via shuffle algebras

We construct the action of the q-deformed W-algebra on its level r representation geometrically, using the moduli space of U(r) instantons on the plane and the double shuffle algebra. We give an explicit LDU decomposition for the action of W-algebra currents in the fixed point basis of the level r representation, and prove a relation between the Carlsson-Okounkov Ext operator and intertwiners for the deformed W-algebra. We interpret this result as a q-deformed version of the AGT-W relations.

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Shuffle algebras associated to surfaces

Flag Hilbert schemes, colored projectors and Khovanov-Rozansky homology