Perils of analytic continuation

Shun-Pei Miao, P. J. Mora, N. C. Tsamis, R. P. Woodard

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

A nice paper by Morrison [arXiv:1302.1860] demonstrates the recent convergence of opinion that has taken place concerning the graviton propagator on de Sitter background. We here discuss the few points which remain under dispute. First, the inevitable decay of tachyonic scalars really does result in their 2-point functions breaking de Sitter invariance. This is obscured by analytic continuation techniques which produce formal solutions to the propagator equation that are not propagators. Second, Morrison's de Sitter invariant solution for the spin two sector of the graviton propagator involves derivatives of the scalar propagator at M2=0, where it is not meromorphic unless de Sitter breaking is permitted. Third, de Sitter breaking does not require zero modes. Fourth, the ambiguity Morrison claims in the equation for the spin two structure function is fixed by requiring it to derive from a mode sum. Fifth, Morrison's spin two sector is not "physically equivalent" to ours because their coincidence limits differ. Finally, it is only the noninvariant propagator that gets the time independence and scale invariance of the tensor power spectrum correctly.

Original languageEnglish
Article number104004
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume89
Issue number10
DOIs
Publication statusPublished - 2014 May 2

Fingerprint

propagation
gravitons
invariance
sectors
scalars
ambiguity
power spectra
tensors
decay

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

Cite this

Miao, Shun-Pei ; Mora, P. J. ; Tsamis, N. C. ; Woodard, R. P. / Perils of analytic continuation. In: Physical Review D - Particles, Fields, Gravitation and Cosmology. 2014 ; Vol. 89, No. 10.
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Perils of analytic continuation. / Miao, Shun-Pei; Mora, P. J.; Tsamis, N. C.; Woodard, R. P.

In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 89, No. 10, 104004, 02.05.2014.

Research output: Contribution to journalArticle

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