Weyl-Weyl correlator in de Donder gauge on de Sitter space

Mora, P. J.; Tsamis, N. C.; Woodard, R. P.

doi:10.1103/physrevd.86.084016

Cited by 36 publications

(24 citation statements)

References 53 publications

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“…We have seen that, in general, the power spectrum is defined as a Fourier transform of the Wightman function with respect to the Killing parameter through Eq. (23). When the Wightman function depends on the co-ordinates only through the geodesic distance (which will be the case for spacelike separations), we can introduce its Fourier transform with respect to Z (or with respect to L 2 ) and express G(Z) in terms of G(Q) (or G(K)), The power spectrum in Eq.…”

Section: Power Spectra Of the Vacuum Noise: An Alternative Approachmentioning

confidence: 99%

Quantum correlators in Friedmann spacetimes: The omnipresent de Sitter spacetime and the invariant vacuum noise

et al. 2018

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We discuss several aspects of quantum field theory of a scalar field in a Friedmann universe. (i) We begin by showing that it is possible to map the dynamics of a scalar field with a given mass, in a given Friedmann background to another scalar field of a different mass in another Friedmann universe. In particular one can map the dynamics of (1) a massless scalar field in a universe with power-law expansion to (2) a massive scalar field in the de Sitter spacetime. This allows us to understand several features of either system in a simple manner and clarifies several issues related to the massless limit. (ii) We relate the Euclidean Green's function for the de Sitter spacetime to the solution of a hypothetical electrostatic problem in D=5 and obtain, in a very simple manner, a useful integral representation for the Green's function. This integral representation is helpful in the study of several relevant limits, and in recovering some key results which are -though known earlier -not adequately appreciated. One of these results is the fact that, in any Friedmann universe, sourced by a negative pressure fluid, the Wightman function for a massless scalar field is divergent. This shows that the divergence of Wightman function for the massless field in the de Sitter spacetime is just a special, limiting, case of this general phenomenon. (iii) We provide a generally covariant procedure for defining the power spectrum of vacuum fluctuations in terms of the different Killing vectors present in the spacetime. This allows one to study the interplay of the choice of vacuum state and the nature of the power spectrum in different co-ordinate systems, in the de Sitter universe, in a unified manner. (iv) As a specific application of this formalism, we discuss the power spectra of vacuum fluctuations in the static (and Painlevé) vacuum states in the de Sitter spacetime and compare them with the corresponding power spectrum in the Bunch-Davies vacuum. We demonstrate how these power spectra are related to each other in a manner similar to the power spectra detected by the inertial and Rindler observers in flat spacetime. This also gives rise to a notion of an invariant vacuum noise in the corresponding spacetimes which is observer independent. (v) In addition, several conceptual and technical issues regarding quantum fields in general cosmological spacetimes are clarified as a part of this study. * kinjalk@iisermohali.ac.in † karthik@iucaa.in ‡

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Section: Power Spectra Of the Vacuum Noise: An Alternative Approachmentioning

confidence: 99%

Quantum correlators in Friedmann spacetimes: The omnipresent de Sitter spacetime and the invariant vacuum noise

et al. 2018

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“…• A computation of the linearized Weyl-Weyl correlator in both the noncovariant [81] and covariant gauges [82].…”

Section: Appendix A: De Sitter Breaking Gaugesmentioning

confidence: 99%

Excitation of photons by inflationary gravitons

Wang

Woodard

2015

Phys. Rev. D

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We use a recent result for the graviton contribution to the one loop vacuum polarization to solve the effective field equations for dynamical photons on de Sitter background. Our results show that the electric field experiences a secular enhancement proportional to the number of inflationary e-foldings. We discuss the minimum this establishes for primordial inflation to seed cosmic magnetic fields.

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“…183 There are still some who believe that the de Sitter breaking evident in the all correct solutions (159)(160)(161)(162) and (171)(172)(173)(174)(175)(176) will drop out when gauge invariant operators are studied, as it does from the linearized Weyl-Weyl correlator. 205,206 I doubt this, and I will point out in section 5.4 that it amounts to re-fighting the same controversy over fields versus potentials which was decided for electromagnetism by the Aharomov-Bohm effect. However, the important thing to note here is that everyone now agrees on the propagators which must be used to make such computations.…”

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confidence: 99%