{ "id": "2207.09952", "version": "v1", "published": "2022-07-20T14:55:08.000Z", "updated": "2022-07-20T14:55:08.000Z", "title": "Toledo invariants of Topological Quantum Field Theories", "authors": [ "Bertrand Deroin", "Julien Marché" ], "comment": "57 pages", "categories": [ "math.GT", "math.DG" ], "abstract": "We prove that the Fibonacci quantum representations $\\rho_{g,n}:\\rm{Mod}_{g,n}\\to \\rm{PU}(p,q)$ for $(g,n)\\in\\{(0,4),(0,5),(1,2),(1,3),(2,1)\\}$ are holonomy representations of complex hyperbolic structures on some compactifications of the corresponding moduli spaces $\\mathcal{M}_{g,n}$. As a corollary, the forgetful map between the corresponding compactifications of $\\mathcal M_{1,3}$ and $\\mathcal M_{1,2}$ is a surjective holomorphic map between compact complex hyperbolic orbifolds of different dimensions higher than one, giving an answer to a problem raised by Siu. The proof consists in computing their Toledo invariants: we put this computation in a broader context, replacing the Fibonacci representations with any Hermitian modular functor and extending the Toledo invariant to a full series of cohomological invariants beginning with the signature $p-q$. We prove that these invariants satisfy the axioms of a Cohomological Field Theory and compute the $R$-matrix at first order (hence the usual Toledo invariants) in the case of the $\\rm{SU}_2/\\rm{SO}_3$-quantum representations at any level.", "revisions": [ { "version": "v1", "updated": "2022-07-20T14:55:08.000Z" } ], "analyses": { "keywords": [ "field theory", "topological quantum field theories", "compact complex hyperbolic orbifolds", "complex hyperbolic structures", "hermitian modular functor" ], "note": { "typesetting": "TeX", "pages": 57, "language": "en", "license": "arXiv", "status": "editable" } } }