Université de GenèveDépartement de Physique ThéoriqueCAP Genève

Neutrino Properties with Ground-Based Millimeter-Wavelength Line Intensity Mapping

4. October 2021
Cite as: 
Azadeh Moradinezhad Dizgah, Garrett K. Keating, Kirit S. Karkare, Abigail Crites, Shouvik Roy Choudhury [arXiv:2110.00014].
Members involved: 

Line intensity mapping (LIM) is emerging as a powerful technique to map the cosmic large-scale structure and to probe cosmology over a wide range of redshifts and spatial scales. We perform Fisher forecasts to determine the optimal design of wide-field ground-based mm-wavelength LIM surveys for constraining properties of neutrinos and light relics. We consider measuring the auto-power spectra of several CO rotational lines (from J=2-1 to J=6-5) and the [CII] fine-structure line in the redshift range of $0.25<z<12$. We study the constraints with and without interloper lines as a source of noise in our analysis, and for several one- and multi-parameter extensions of $\Lambda$CDM. We show that LIM surveys deployable this decade, in combination with existing CMB (primary) data, could achieve order of magnitude improvements over Planck constraints on $N_{\rm eff}$ and $M_\nu$. Compared to next-generation CMB and galaxy surveys, a LIM experiment of this scale could achieve bounds that are a factor of $\sim3$ better than those forecasted for surveys such as EUCLID (galaxy clustering), and potentially exceed the constraining power of CMB-S4 by a factor of $\sim1.5$ and $\sim3$ for $N_{\rm eff}$ and $M_\nu$, respectively. We show that the forecasted constraints are not substantially affected when enlarging the parameter space, and additionally, demonstrate that such a survey could also be used to measure $\Lambda$CDM parameters and the dark energy equation of state exquisitely well.


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