2014/01/31 by Christian Fidler, Guido W. Pettinari, Martin Beneke +3 · 31 citations
Physics and Astronomy · #Bolometer #Boltzmann constant #Boltzmann equation #COSMIC cancer database #Cosmic background radiation #Cosmic microwave background #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Pulsars and Gravitational Waves Research #Redshift #SIGNAL (programming language) #astro-ph.CO #gr-qc
paper · pdf · doi:10.1088/1475-7516/2014/07/011
published in Journal of Cosmology and Astroparticle Physics 2014(07), 011 (Institute of Physics)
arxiv created 2014/06/05 · openalex publication_date 2014/07/07 · arxiv updated 2014/09/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We estimate the B-polarisation induced in the Cosmic Microwave Background by the non-linear evolution of density perturbations. Using the second-order Boltzmann code SONG, our analysis incorporates, for the first time, all physical effects at recombination. We also include novel contributions from the redshift part of the Boltzmann equation and from the bolometric definition of the temperature in the presence of polarisation. The remaining line-of-sight terms (lensing and time-delay) have previously been studied and must be calculated non-perturbatively. The intrinsic B-mode polarisation is present independent of the initial conditions and might contaminate the signal from primordial gravitational waves. We find this contamination to be comparable to a primordial tensor-to-scalar ratio of r≃10-7 at the angular scale ℓ≃100 , where the primordial signal peaks, and r≃ 5 ⋅ 10-5 at ℓ≃700 , where the intrinsic signal peaks. Therefore, we conclude that the intrinsic B-polarisation from second-order effects is not likely to contaminate future searches of primordial gravitational waves.