Perils of analytic continuation

S. P. Miao, P. J. Mora, N. C. Tsamis, R. P. Woodard

研究成果: Article同行評審

21 引文 斯高帕斯(Scopus)


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.

期刊Physical Review D - Particles, Fields, Gravitation and Cosmology
出版狀態Published - 2014 5月 2

All Science Journal Classification (ASJC) codes

  • 核能與高能物理
  • 物理與天文學(雜項)


深入研究「Perils of analytic continuation」主題。共同形成了獨特的指紋。