Local primordial non-Gaussianity using cross-correlations of DESI tracers

A. J. Rosado-Marín; A. J. Ross; H. Seo; E. Chaussidon; J. Aguilar; S. Ahlen; D. Bianchi; D. Brooks; T. Claybaugh; A. Cuceu; A. de la Macorra; A. de Mattia; R. Demina; B. Dey; P. Doel; S. Ferraro; A. Font-Ribera; J. E. Forero-Romero; E. Gaztañaga; S. Gontcho A Gontcho; G. Gutierrez; C. Hahn; H. K. Herrera-Alcantar; D. Huterer; M. Ishak; R. Joyce; D. Kirkby; A. Kremin; O. Lahav; C. Lamman; M. Landriau; M. E. Levi; M. Manera; A. Meisner; R. Miquel; S. Nadathur; J. A. Newman; N. Palanque-Delabrouille; W. J. Percival; F. Prada; I. Pérez-Ràfols; G. Rossi; E. Sanchez; D. Schlegel; J. Silber; G. Tarlé; B. A. Weaver; C. Zhao; H. Zou

arXiv · 2604.05213

Local primordial non-Gaussianity using cross-correlations of DESI tracers

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Abstract

We constrain local primordial non-Gaussianity by a combined analysis of auto and cross-correlations of DESI DR1 tracers, leveraging LRGs and QSOs as well as ELGs between $0.8<z<3.1$. By cross-validating the signal across different clustering tracers within the same redshift range, we evaluate potential systematics in the $f^\mathrm{loc}_\mathrm{NL}$ measurements, capitalizing on the reduced susceptibility of cross-correlations to non-common systematics. We find that the cross-correlation between LRG and quasars can robustly improve the DESI DR1 $f^\mathrm{loc}_\mathrm{NL}$ constraints, by $\sim9\%$ to a measurement of $f^\mathrm{loc}_\mathrm{NL}=2.1_{-8.3}^{+8.8}$ at 68\% confidence. On the other hand, we do not find a clear improvement when including the DESI DR1 ELG sample. Mock tests predict an additional $\sim8\%$ gain with statistical scatter, and the lack of improvement in the data remains consistent with this expectation. This project serves as an exploratory analysis of DESI ELG clustering for $f^\mathrm{loc}_\mathrm{NL}$ through its cross-correlation in preparation for future DESI data analyses.

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A. J. Rosado-Marín, A. J. Ross, H. Seo, E. Chaussidon, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, A. Cuceu, A. de la Macorra, A. de Mattia, R. Demina, B. Dey, P. Doel, S. Ferraro, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, G. Gutierrez, C. Hahn, H. K. Herrera-Alcantar, D. Huterer, M. Ishak, R. Joyce, D. Kirkby, A. Kremin, O. Lahav, C. Lamman, M. Landriau, M. E. Levi, M. Manera, A. Meisner, R. Miquel, S. Nadathur, J. A. Newman, N. Palanque-Delabrouille, W. J. Percival, F. Prada, I. Pérez-Ràfols, G. Rossi, E. Sanchez, D. Schlegel, J. Silber, G. Tarlé, B. A. Weaver, C. Zhao, H. Zou. 2026-04-06. Local primordial non-Gaussianity using cross-correlations of DESI tracers. https://arxiv.org/abs/2604.05213

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