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arXiv · 2309.06477

Constraining Cosmology With the CMB $\times$ LIM-Nulling Convergence

Hannah Fronenberg·Abhishek S. Maniyar·Anthony R. Pullen·Adrian Liu
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Abstract

Lensing reconstruction maps from the cosmic microwave background (CMB) provide direct observations of the matter distribution of the universe without the use of a biased tracer. Such maps, however, constitute projected observables along the line of sight that are dominated by their low-redshift contributions. To cleanly access high-redshift information, Maniyar et al. showed that a linear combination of lensing maps from both CMB and line intensity mapping (LIM) observations can exactly null the low-redshift contribution to CMB lensing convergence. In this paper we explore the scientific returns of this nulling technique. We show that LIM-nulling estimators can place constraints on standard $\Lambda$CDM plus neutrino mass parameters that are competitive with traditional CMB lensing. Additionally, we demonstrate that as a clean probe of the high-redshift universe, LIM-nulling can be used for model-independent tests of cosmology beyond $\Lambda$CDM and as a probe of the high-redshift matter power spectrum.

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Hannah Fronenberg, Abhishek S. Maniyar, Anthony R. Pullen, Adrian Liu. 2023-09-12. Constraining Cosmology With the CMB $\times$ LIM-Nulling Convergence. https://doi.org/10.1103/physrevd.109.123518

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