The string group through shifted geometric quantization

Aditya Dwarkesh explains how geometric quantization extends from ordinary symplectic geometry to higher stacks represented by simplicial manifolds. Whereas ordinary prequantization produces line bundles, the shifted setting leads to bundle gerbes, higher-categorical analogues of principal bundles. For a compact simple Lie group G, the string group provides an example of a multiplicative bundle gerbe over G and can be understood through prequantization of BG with a 2-shifted symplectic structure. The talk develops this relationship and may include a sketch of a new model for String(G).