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Spinorial geometry and Killing spinor equations of 6D supergravity. (English) Zbl 1217.83048

Summary: We solve the Killing spinor equations of six-dimensional \((1, 0)\)-supergravity coupled to any number of tensor, vector and scalar multiplets in all cases. The isotropy groups of Killing spinors are \(Sp(1)\cdot Sp(1)\ltimes \mathbb H(1), U(1)\cdot Sp(1)\ltimes \mathbb H(2), Sp(1)\ltimes \mathbb H(3,4), Sp(1)(2), U(1)(4)\) and {1}(8), where in parenthesis is the number of supersymmetries preserved in each case. If the isotropy group is non-compact, the spacetime admits a parallel null 1-form with respect to a connection with torsion given by the 3-form field strength of the gravitational multiplet. The associated vector field is Killing and the 3-form is determined in terms of the geometry of spacetime. The \(Sp(1) \ltimes \mathbb H\) case admits a descendant solution preserving three out of four supersymmetries due to the hyperini Killing spinor equation. If the isotropy group is compact, the spacetime admits a natural frame constructed from 1-form spinor bi-linears. In the \(Sp(1)\) and \(U(1)\) cases, the spacetime admits three and four parallel 1-forms with respect to the connection with torsion, respectively. The associated vector fields are Killing and under some additional restrictions the spacetime is a principal bundle with fibre a Lorentzian Lie group. The conditions imposed by the Killing spinor equations on all other fields are also determined.

MSC:

83E50 Supergravity
83C60 Spinor and twistor methods in general relativity and gravitational theory; Newman-Penrose formalism
83C40 Gravitational energy and conservation laws; groups of motions
83C75 Space-time singularities, cosmic censorship, etc.
15A72 Vector and tensor algebra, theory of invariants