منابع مشابه
Octonionic Gravitational Instantons
We construct eight-dimensional gravitational instantons by solving appropriate selfduality equations for the spin-connection. The particular gravitational instanton we present has Spin(7) holonomy and, in a sense, it is the eight-dimensional analog of the Eguchi-Hanson 4D space. It has a removable bolt singularity which is topologically S4 and its boundary at infinity is the squashed S7. We als...
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This work presents a classification of all smooth ’t Hooft–Jackiw–Nohl–Rebbi instantons over Gibbons–Hawking spaces. That is, we find all smooth SU(2) Yang–Mills instantons over these spaces which arise by conformal rescalings of the metric with suitable functions. Since the Gibbons–Hawking spaces are hyper-Kähler gravitational instantons, the rescaling functions must be positive harmonic. By u...
متن کاملGravitational Dressing of D-Instantons
The non-perturbative corrections to the universal hypermultiplet moduli space metric in the type-IIA superstring compactification on a Calabi-Yau threefold are investigated in the presence of 4d, N=2 supergravity. These corrections come from multiple wrapping of the BPS (Euclidean) D2-branes around certain (BPS) Calabi-Yau 3-cycles, and they are known as the D-instantons. The exact universal hy...
متن کاملHodge cohomology of gravitational instantons
We study the space of L harmonic forms on complete manifolds with metrics of fibred boundary or fibred cusp type. These metrics generalize the geometric structures at infinity of several different well-known classes of metrics, including asymptotically locally Euclidean manifolds, the (known types of) gravitational instantons, and also Poincaré metrics on Qrank 1 ends of locally symmetric space...
متن کاملGravitational Instantons in Ashtekar’s Formalism
Gravitational instantons of Bianchi type IX space are constructed in Ashtekar’s canonical formalism. Instead of solving the self-duality condition, we fully solve the constraint on the “initial surface” and “Hamiltonian equations”. This formallism is applicable to the matter coupled system with cosmological constant.
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ژورنال
عنوان ژورنال: Communications in Mathematical Physics
سال: 2005
ISSN: 0010-3616,1432-0916
DOI: 10.1007/s00220-005-1404-8