Reply Comment: Comparison of approaches to classical signature change

Hellaby, Charles; Dray, Tevian

Citeable URL: https://ir.library.oregonstate.edu/concern/articles/1v53jx42j

Original Article: Charles Hellaby and Tevian Dray, Failure of standard conservation laws at a classical change of signature, Physical Review D 49(10), 5096-5104 (1994). The original article can be found at the following link in ScholarsArchive@OSU: http://hdl.handle.net/1957/41872

This is the publisher’s final pdf. The published article is copyrighted by the American Physical Society and can be found at: http://prd.aps.org/.

Descriptions

Attribute Name	Values
Creator	Hellaby, Charles Dray, Tevian
Abstract	We contrast the two approaches to ‘‘classical’’ signature change used by Hayward with the one used by us (Hellaby and Dray). There is (as yet) no rigorous derivation of appropriate distributional field equations. Hayward’s distributional approach is based on a postulated modified form of the field equations. We make an alternative postulate. We point out an important difference between two possible philosophies of signature change—ours is strictly classical, while Hayward’s Lagrangian approach adopts what amounts to an imaginary proper ‘‘time’’ on one side of the signature change, as is explicitly done in quantum cosmology. We also explain why we chose to use the Darmois-Israel-type junction conditions, rather than the Lichnerowicz-type junction conditions favored by Hayward. We show that the difference in results is entirely explained by the difference in philosophy (imaginary versus real Euclidean ‘‘time’’), and not by the difference in approach to junction conditions (Lichnerowicz with specific coordinates versus Darmois with general coordinates).
Resource Type	Article
DOI	https://doi.org/10.1103/PhysRevD.52.7333
Date Available	2013-08-21T00:38:09+00:00
Date Issued	1995-12-15
Citation	Hellaby, C., & Dray, T. (1995). Reply comment: Comparison of approaches to classical signature change. Physical Review D, 52(12), 7333-7339. doi:10.1103/PhysRevD.52.7333
Journal Title	Physical Review D
Journal Volume	52
Journal Issue/Number	12
Academic Affiliation	Mathematics
Rights Statement	Copyright Not Evaluated
Funding Statement (additional comments about funding)	C.H. would like to thank the FRD for a research grant. T.D. was partially funded by NSF Grant No. PHY-9208494.
Publisher	American Physical Society
Peer Reviewed	Yes
Language	English [eng]
Replaces	http://hdl.handle.net/1957/41874
Additional Information	description.provenance : Approved for entry into archive by Deanne Bruner(deanne.bruner@oregonstate.edu) on 2013-08-21T00:38:09Z (GMT) No. of bitstreams: 1 DrayTevianMathematicsReplyCommentComparison.pdf: 319558 bytes, checksum: e4a005f3d9e42cc98eead988a4096237 (MD5) description.provenance : Made available in DSpace on 2013-08-21T00:38:09Z (GMT). No. of bitstreams: 1 DrayTevianMathematicsReplyCommentComparison.pdf: 319558 bytes, checksum: e4a005f3d9e42cc98eead988a4096237 (MD5) Previous issue date: 1995-12-15 description.provenance : Submitted by Deanne Bruner (deanne.bruner@oregonstate.edu) on 2013-08-21T00:36:43Z No. of bitstreams: 1 DrayTevianMathematicsReplyCommentComparison.pdf: 319558 bytes, checksum: e4a005f3d9e42cc98eead988a4096237 (MD5)

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