Kleinian signature change
نویسندگان
چکیده
منابع مشابه
Signature change induces compactification.
It is shown – using a FRW model with S 3 × S 6 as spatial sections and a positive cosmological constant – that classical signature change implies a new compactification mechanism. The internal scale factor is of the order Λ −1/2 , and the solutions are stable against small perturbatons. In the case of compactified S 6 , it is shown that the effective four-dimensional space-time metric has Loren...
متن کاملSignature Change and Clifford Algebras
Given the real Clifford algebra of a quadratic space with a given signature, we define a new product in this structure such that it simulates the Clifford product of a quadratic space with another signature different from the original one. Among the possible applications of this new product, we use it in order to write the minkowskian Dirac equation over the euclidean spacetime and to define a ...
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The change of signature of a metric is explained using simple examples and methods. The Klein-Gordon field on a signature-changing background is discussed, and it is shown how the approach of Dray et al. can be corrected to ensure that the KleinGordon equation holds. Isotropic cosmologies are discussed, and it is shown how the approach of Ellis et al. can be corrected to ensure that the Einstei...
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Arithmetic Kleinian groups are arithmetic lattices in PSL2(C). We present an algorithm that, given such a group Γ, returns a fundamental domain and a finite presentation for Γ with a computable isomorphism.
متن کاملSelf - adjoint extensions and Signature Change
We study the selfadjoint extensions of the spatial part of the D'Alembert operator in a spacetime with two changes of signature. We identify a set of boundary conditions, parametrised by U (2) matrices, which correspond to Dirichlet boundary conditions for the fields, and from which we argue against the suggestion that regions of signature change can isolate singularities.
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ژورنال
عنوان ژورنال: Classical and Quantum Gravity
سال: 1994
ISSN: 0264-9381,1361-6382
DOI: 10.1088/0264-9381/11/10/012