Cosmic microwave background fluctuations from gravitational waves: An analytic approach☆

By J. Pritchard, M. Kamionkowski. 2004

135 citations recorded by the source corpus.

Abstract We develop an analytic approach to calculation of the temperature and polarisation power spectra of the cosmic microwave background due to inflationary gravitational waves. This approach complements the more precise numerical results by providing insight into the physical origins of the features in the power spectra. We explore the use of analytic approximations for the gravitational-wave evolution, making use of the WKB approach to handle the radiation-matter transition. In the process, we describe scaling relations for the temperature and polarisation power spectra. We illustrate the dependence of the amplitude, shape, and peak locations on the details of recombination, the gravitational-wave power spectrum, and the cosmological parameters, and explain the origin of the peak locations in the temperature and polarisation power spectra. The decline in power on small scales in the polarisation power spectra is discussed in terms of phase-damping. In an appendix we detail numerical techniques for integrating the gravitational-wave evolution in the presence of anisotropic stress from free-streaming neutrinos.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/735b89ad301b32e2c50f5cd1f19105a97137b4c3

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Citations in the corpus

Three Year Wilkinson Microwave Anistropy Probe (WMAP) Observations: Polarization Analysis (2006, methodology): “…include using (1) an instantaneous transition from radiation to matter dominatio (Abbott & Harari 1986; Ng & Speliotopoulos 1995; Grishchuk 2001; Pritchard & Kamionkowski 2005, e.g.,) (2) a “transfer function” to account for the smooth transition from radiation domination to matter domination…”
The Quest for B Modes from Inflationary Gravitational Waves (2015, background): “The anisotropic stress of this fluid (to which the neutrino background contributes after neutrinos decouple) modifies slightly the time evolution, a calculable ∼ 10% correction to Equation 21 (Weinberg 2004; Pritchard & Kamionkowski 2005; Dicus & Repko 2005).”