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arXiv · 2411.08152

Assessing the growth of structure over cosmic time with CMB lensing

Mathew S. Madhavacheril
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Abstract

The standard $\Lambda$CDM cosmological model informed by cosmic microwave background (CMB) anisotropies makes a precise prediction for the growth of matter density fluctuations over cosmic time on linear scales. A variety of cosmological observables offer independent and complementary ways of testing this prediction, but results have been mixed, with many constraints on the amplitude of structure $S_8$ being 2-3$\sigma$ lower than the expectation from Planck primary CMB anisotropies. It is currently unclear whether these discrepancies are due to observational systematics, non-linearities and baryonic effects or new physics. We review how gravitational lensing of the CMB has and will continue to provide insights into this problem, including through tomographic cross-correlations with galaxy surveys over cosmic time.

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Mathew S. Madhavacheril. 2024-11-12. Assessing the growth of structure over cosmic time with CMB lensing. https://arxiv.org/abs/2411.08152

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