# Cosmological constraints from the DESI DR1 joint power spectrum and bispectrum analysis

**Authors:** S. Novell-Masot, H. Gil-Marín, L. Verde, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, F. J. Castander, T. Claybaugh, S. Cole, A. de la Macorra, J. Della Costa, S. Ferraro, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, A. X. Gonzalez-Morales, G. Gutierrez, J. Guy  
**arXiv:** [2603.19356](https://arxiv.org/abs/2603.19356)  
**Date:** 2026-03-19  
**Summary page:** https://www.summarizepaper.com/en/paper/2603.19356v1/

## Key points

- Cosmological parameter constraints derived from DESI DR1 galaxy clustering data using the ShapeFit framework
- First ShapeFit cosmological inference results based on the bispectrum of DESI DR1
- Constraints on crucial parameters such as matter density ($Ω_m=0.310\pm0.012$) and Hubble constant ($H_0=[68.92\pm0.97]\,\mathrm{km\, s^{-1} Mpc^{-1}$)
- Significant enhancement in constraint precision for fluctuations' amplitude by integrating the bispectrum into analysis
- Exploration of evolving dark energy equation-of-state $w_0w_a$ and sum of neutrino masses $\sum m_ν$
- Consistency with standard $Λ$CDM model assumptions and expectations for dark energy equation-of-state and neutrino mass within a 2σ range

## Summary

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We present cosmological parameter constraints derived from the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) galaxy clustering data using the ShapeFit framework. Our analysis includes a comprehensive examination of the power spectrum multipoles and bispectrum monopole, building upon our previous work where we established constraints on ShapeFit parameters using the bispectrum of DESI DR1. The key highlight of our research is the first ShapeFit cosmological inference results based on the bispectrum of DESI DR1, which reveals values for crucial parameters such as matter density ($Ω_m=0.310\pm0.012$) and Hubble constant ($H_0=[68.92\pm0.97]\,\mathrm{km\, s^{-1} Mpc^{-1}$). These results align with earlier findings from analyses of the full DESI DR1 dataset that did not incorporate the bispectrum signal. By integrating the bispectrum into our analysis, we observe a significant enhancement in constraint precision for fluctuations' amplitude, leading to a notable reduction in error-bars in $\ln(A_s\times10^{10})$ by approximately 20% compared to relying solely on power spectrum data. Furthermore, we extend our exploration to encompass more intricate cosmological models by conducting fits for evolving dark energy equation-of-state $w_0w_a$ and sum of neutrino masses $\sum m_ν$. While our constraints slightly surpass those from prior works by the DESI collaboration due to not amalgamating full-shape results with other probes across all tracers, we find no compelling evidence indicating deviations from standard $Λ$CDM model assumptions. Our analysis reveals that both dark energy equation-of-state and neutrino mass remain consistent with expectations within a 2σ range from a cosmological constant $Λ$ and normal hierarchy for neutrino mass distribution respectively ($\sum m_ν<0.1\,[eV]$ at 95% confidence limit). These outcomes are broadly in line with other DESI DR1 analyses, underscoring the robustness of employing ShapeFit compression methodology alongside incorporating bispectrum data for precise cosmological inference.