Hyperkähler and quaternionic Kähler geometry

<p>A quaternion-Hermitian manifold, of dimension at least 12, with closed fundamental 4-form is shown to be quaternionic Kähler. A similar result is proved for 8-manifolds.</p> <p>HyperKähler metrics are constructed on the fundamental quaternionic line bundle (with the zero-sectio...

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Váldodahkki: Swann, A
Eará dahkkit: Salamon, S
Materiálatiipa: Oahppočájánas
Giella:English
Almmustuhtton: 1990
Fáttát:
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author Swann, A
author2 Salamon, S
author_facet Salamon, S
Swann, A
author_sort Swann, A
collection OXFORD
description <p>A quaternion-Hermitian manifold, of dimension at least 12, with closed fundamental 4-form is shown to be quaternionic Kähler. A similar result is proved for 8-manifolds.</p> <p>HyperKähler metrics are constructed on the fundamental quaternionic line bundle (with the zero-section removed) of a quaternionic Kähler manifold (indefinite if the scalar curvature is negative). This construction is compatible with the quaternionic Kähler and hyperKähier quotient constructions and allows quaternionic Kähler geometry to be subsumed into the theory of hyperKähler manifolds. It is shown that the hyperKähler metrics that arise admit a certain type of <em>SU</em>(2)- action, possess functions which are Kähler potentials for each of the complex structures simultaneously and determine quaternionic Kähler structures via a variant of the moment map construction. Quaternionic Kähler metrics are also constructed on the fundamental quaternionic line bundle and a twistor space analogy leads to a construction of hyperKähler metrics with circle actions on complex line bundles over Kähler-Einstein (complex) contact manifolds.</p> <p>Nilpotent orbits in a complex semi-simple Lie algebra, with the hyperKähler metrics defined by Kronheimer, are shown to give rise to quaternionic Kähler metrics and various examples of these metrics are identified. It is shown that any quaternionic Kähler manifold with positive scalar curvature and sufficiently large isometry group may be embedded in one of these manifolds. The twistor space structure of the projectivised nilpotent orbits is studied.</p>
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spelling oxford-uuid:bb301f35-25e0-445d-8045-65e402908b852022-03-27T05:15:13ZHyperkähler and quaternionic Kähler geometryThesishttp://purl.org/coar/resource_type/c_db06uuid:bb301f35-25e0-445d-8045-65e402908b85Manifolds (Mathematics)Geometry, DifferentialEnglishPolonsky Theses Digitisation Project1990Swann, ASalamon, SSalamon, S<p>A quaternion-Hermitian manifold, of dimension at least 12, with closed fundamental 4-form is shown to be quaternionic Kähler. A similar result is proved for 8-manifolds.</p> <p>HyperKähler metrics are constructed on the fundamental quaternionic line bundle (with the zero-section removed) of a quaternionic Kähler manifold (indefinite if the scalar curvature is negative). This construction is compatible with the quaternionic Kähler and hyperKähier quotient constructions and allows quaternionic Kähler geometry to be subsumed into the theory of hyperKähler manifolds. It is shown that the hyperKähler metrics that arise admit a certain type of <em>SU</em>(2)- action, possess functions which are Kähler potentials for each of the complex structures simultaneously and determine quaternionic Kähler structures via a variant of the moment map construction. Quaternionic Kähler metrics are also constructed on the fundamental quaternionic line bundle and a twistor space analogy leads to a construction of hyperKähler metrics with circle actions on complex line bundles over Kähler-Einstein (complex) contact manifolds.</p> <p>Nilpotent orbits in a complex semi-simple Lie algebra, with the hyperKähler metrics defined by Kronheimer, are shown to give rise to quaternionic Kähler metrics and various examples of these metrics are identified. It is shown that any quaternionic Kähler manifold with positive scalar curvature and sufficiently large isometry group may be embedded in one of these manifolds. The twistor space structure of the projectivised nilpotent orbits is studied.</p>
spellingShingle Manifolds (Mathematics)
Geometry, Differential
Swann, A
Hyperkähler and quaternionic Kähler geometry
title Hyperkähler and quaternionic Kähler geometry
title_full Hyperkähler and quaternionic Kähler geometry
title_fullStr Hyperkähler and quaternionic Kähler geometry
title_full_unstemmed Hyperkähler and quaternionic Kähler geometry
title_short Hyperkähler and quaternionic Kähler geometry
title_sort hyperkahler and quaternionic kahler geometry
topic Manifolds (Mathematics)
Geometry, Differential
work_keys_str_mv AT swanna hyperkahlerandquaternionickahlergeometry