1. It's not $\sigma_8$ : constraining the non-linear matter power spectrum with the Dark Energy Survey Year-5 supernova sample
- Author
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Shah, Paul, Davis, T. M., Vincenzi, M., Armstrong, P., Brout, D., Camilleri, R., Galbany, L., Gill, M. S. S., Huterer, D., Jeffrey, N., Lahav, O., Lee, J., Lidman, C., Möller, A., Sullivan, M., Whiteway, L., Wiseman, P., Allam, S., Aguena, M., Annis, J., Blazek, J., Brooks, D., Rosell, A. Carnero, Carretero, J., Conselice, C., da Costa, L. N., Pereira, M. E. S., Desai, S., Diehl, H. T., Doel, P., Everett, S., Ferrero, I., Flaugher, B., Frieman, J., García-Bellido, J., Gaztanaga, E., Giannini, G., Gruen, D., Gruendl, R. A., Gutierrez, G., Hinton, S. R., Hollowood, D. L., Honscheid, K., James, D. J., Lee, S., Marshall, J. L., Mena-Fernández, J., Miquel, R., Palmese, A., Pieres, A., Malagón, A. A. Plazas, Porredon, A., Samuroff, S., Sanchez, E., Sevilla-Noarbe, I., Smith, M., Suchyta, E., Swanson, M. E. C., Tarle, G., Tucker, D. L., and Weaverdyck, N.
- Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The weak gravitational lensing magnification of Type Ia supernovae (SNe Ia) is sensitive to the matter power spectrum on scales $k>1 h$ Mpc$^{-1}$, making it unwise to interpret SNe Ia lensing in terms of power on linear scales. We compute the probability density function of SNe Ia magnification as a function of standard cosmological parameters, plus an empirical parameter $A_{\rm mod}$ which describes the suppression or enhancement of matter power on non-linear scales compared to a cold dark matter only model. While baryons are expected to enhance power on the scales relevant to SN Ia lensing, other physics such as neutrino masses or non-standard dark matter may suppress power. Using the Dark Energy Survey Year-5 sample, we find $A_{\rm mod} = 0.77^{+0.69}_{-0.40}$ (68\% credible interval around the median). Although the median is consistent with unity there are hints of power suppression, with $A_{\rm mod} < 1.09$ at 68\% credibility., Comment: 12 pages, submitted to MNRAS. arXiv admin note: text overlap with arXiv:2410.07956
- Published
- 2025