Geometric interpretation of approximations of Nichols algebras

Nichols algebras are graded Hopf algebras playing a prominent role in the study of pointed Hopf algebras and comprising symmetric algebras, exterior algebras and the positive part of quantized universal enveloping algebras. Kapranov and Schechtman have given a geometric interpretation of primitive bialgebras in terms of factorizable perverse sheaves. Through this equivalence, Nichols algebras correspond to IC complexes. In ongoing joint work in progress with Giovanna Carnovale and Lleonard Rubio y Degrassi, we give a geometric interpretation as well of approximations of Nichols algebras. This allows to reformulate geometrically various open problems on Nichols algebras.