{ "id": "math/9910002", "version": "v1", "published": "1999-10-01T11:07:45.000Z", "updated": "1999-10-01T11:07:45.000Z", "title": "A new construction of compact 8-manifolds with holonomy Spin(7)", "authors": [ "Dominic Joyce" ], "comment": "43 pages, LaTeX, uses packages amstex and amssymb", "journal": "J.Diff.Geom. 53 (1999) 89-130", "categories": [ "math.DG", "hep-th" ], "abstract": "The exceptional holonomy groups are G2 in 7 dimensions, and Spin(7) in 8 dimensions. In a previous paper (Invent. math. 123 (1996), 507-552) the author constructed the first examples of compact 8-manifolds with holonomy Spin(7), by resolving orbifolds T^8/G, where T^8 is the 8-torus and G a finite group of automorphisms of T^8. This paper describes a different construction of compact 8-manifolds with holonomy Spin(7). We start with a Calabi-Yau 4-orbifold Y with isolated singularities, and an isometric, antiholomorphic involution \\sigma of Y fixing only the singular points. Let Z=Y/<\\sigma>. Then Z is an orbifold with isolated singularities, and a natural Spin(7)-structure. We resolve the singular points of Z to get a compact 8-manifold M, and show that M has holonomy Spin(7). Taking Y to be a hypersurface in a complex weighted projective space, we construct new examples of compact 8-manifolds with holonomy Spin(7), and calculate their Betti numbers b^k. The fourth Betti number b^4 tends to be rather large, as high as 11,662 in one example.", "revisions": [ { "version": "v1", "updated": "1999-10-01T11:07:45.000Z" } ], "analyses": { "keywords": [ "holonomy spin", "construction", "singular points", "exceptional holonomy groups", "fourth betti number" ], "tags": [ "journal article" ], "note": { "typesetting": "AMS-TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable", "inspire": 508123, "adsabs": "1999math.....10002J" } } }