| 1. |
- Persson, Daniel, 1978, et al.
(författare)
-
Generalised Moonshine and Holomorphic Orbifolds
- 2015
-
Ingår i: Proceedings of Symposia in Pure Mathematics - Conference on String-Math 2012. - Providence, Rhode Island : American Mathematical Society. - 2324-707X. - 9780821894958 ; 90, s. 73-86
-
Konferensbidrag (refereegranskat)abstract
- Generalised moonshine is reviewed from the point of view of holomorphic orbifolds, putting special emphasis on the role of the third cohomology group H^3(G, U(1)) in characterising consistent constructions. These ideas are then applied to the case of Mathieu moonshine, i.e. the recently discovered connection between the largest Mathieu group M_24 and the elliptic genus of K3. In particular, we find a complete list of twisted twining genera whose modular properties are controlled by a class in H^3(M_24, U(1)), as expected from general orbifold considerations.
|
|
| 2. |
- Persson, Daniel, 1978, et al.
(författare)
-
Quantum hypermultiplet moduli spaces in N=2 string vacua: a review
- 2015
-
Ingår i: Proceedings of Symposia in Pure Mathematics - Conference on String-Math 2012. - Providence, Rhode Island : American Mathematical Society. - 2324-707X. - 9780821894958 ; 90, s. 181-211
-
Konferensbidrag (refereegranskat)abstract
- The hypermultiplet moduli space M_H in type II string theories compactified on a Calabi-Yau threefold X is largely constrained by supersymmetry (which demands quaternion-K\"ahlerity), S-duality (which requires an isometric action of SL(2, Z)) and regularity. Mathematically, M_H ought to encode all generalized Donaldson-Thomas invariants on X consistently with wall-crossing, modularity and homological mirror symmetry. We review recent progress towards computing the exact metric on M_H, or rather the exact complex contact structure on its twistor space.
|
|
