Munshi, D. and Hu, B. and Matsubara, T. and Coles, Peter and Heavens, A.F. (2016) Lensing-induced morphology changes in CMB temperature maps in modified gravity theories. Journal of Cosmology and Astroparticle Physics, 2016 (04). 056. ISSN 1475-7516

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Abstract

Lensing of the Cosmic Microwave Background (CMB) changes the morphology of pattern of temperature fluctuations, so topological descriptors such as Minkowski Functionals can probe the gravity model responsible for the lensing. We show how the recently introduced two-to-two and three-to-one kurt-spectra (and their associated correlation functions), which depend on the power spectrum of the lensing potential, can be used to probe modified gravity theories such as f(R) theories of gravity and quintessence models. We also investigate models based on effective field theory, which include the constant-Ω model, and low-energy Hořava theories. Estimates of the cumulative signal-to-noise for detection of lensing-induced morphology changes, reaches Script O(103) for the future planned CMB polarization mission COrE+. Assuming foreground removal is possible to ℓmax=3000, we show that many modified gravity theories can be rejected with a high level of significance, making this technique comparable in power to galaxy weak lensing or redshift surveys. These topological estimators are also useful in distinguishing lensing from other scattering secondaries at the level of the four-point function or trispectrum. Examples include the kinetic Sunyaev-Zel'dovich (kSZ) effect which shares, with lensing, a lack of spectral distortion. We also discuss the complication of foreground contamination from unsubtracted point sources.

Item Type:	Article
Keywords:	CMBR theory; modified gravity; non-gaussianity;
Academic Unit:	Faculty of Science and Engineering > Theoretical Physics
Item ID:	12502
Identification Number:	https://doi.org/10.1088/1475-7516/2016/04/056
Depositing User:	Peter Coles
Date Deposited:	03 Mar 2020 16:43
Journal or Publication Title:	Journal of Cosmology and Astroparticle Physics
Publisher:	IOP Publishing
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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