Year: 2018
Type: preprint
Abstract: We prove a Fredholm property for spin-c Dirac operators $\mathsf{D}$ on non-compact manifolds satisfying a certain condition with respect to the action of a semi-direct product group $K\ltimes Γ$, with $K$ compact and $Γ$ discrete. We apply this result to an example coming from the theory of Hamiltonian loop group spaces. In this context we prove that a certain index pairing $[\mathcal{X}] \cap [\mathsf{D}]$ yields an element of the formal completion $R^{-\infty}(T)$ of the representation ring of a maximal torus $T \subset G$; the resulting element has an additional antisymmetry property under the action of the affine Weyl group, indicating $[\mathcal{X}] \cap [\mathsf{D}]$ corresponds to an element of the ring of projective positive energy representations of the loop group.
Source: arXiv (Cornell University)
Authors: Loizides, Yiannis, Song, Yanli
Language: English
Subfield: Mathematical Physics
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2949886010