Cosmological constraints from the DESI DR1 Bispectrum Full-Shape and DR2 BAO
Abstract
We present cosmological constraints from DESI DR1 full-shape measurements, including the LRG bispectrum, combined with DESI DR2 BAO data. The analysis accounts for cross-covariance using mocks, while ShapeFit compression mitigates prior volume effects in beyond-ΛCDM analyses. In ΛCDM, the DESI1.5 (P+B) analysis yields σ8=0.868±0.026 and S8=0.880±0.028, compared with σ8=0.822±0.034 and S8=0.827±0.036 in the previous power-spectrum-only analysis. The marginalized uncertainties are reduced by 24% and 22%, respectively. For w0waCDM, DESI-only analyses with the bispectrum shift dark energy parameters toward ΛCDM, consistent with a cosmological constant within 1σ in the w0--wa plane. Adding CMB creates a preference for evolving dark energy: DESI+CMB (P+B) shows a 2.8σ deviation from ΛCDM. Including DES-Dovekie supernovae alone reduces this to 1.6σ, while the full combination gives 3.1σ. The bispectrum weakens evidence for time-varying dark energy relative to power-spectrum-only analyses. It also enhances sensitivity to massive neutrinos: in DESI-only data, the power-spectrum-only posterior for ∑ mν is consistent with zero, whereas adding the bispectrum yields 0.26±0.18 eV and a 95% upper limit of $0.59$ eV, shifting the peak into the positive region. For modified gravity, the bispectrum constrains μ0 = 0.12±0.51 from DESI-only data, consistent with general relativity.
Related
- Cosmological inference from a joint DESI DR1 full-shape power spectrum and bispectrum analysis
- Cosmological Constraints from Full-scale Clustering and Galaxy–Galaxy Lensing with DESI DR1
- Constraints on Primordial Oscillatory Features from the Power Spectrum and Bispectrum of Redshift-Space Galaxy Clustering in DESI DR1
- Reanalyzing DESI DR1: IV. Percent-level cosmological constraints from combined probes and robust evidence for the normal neutrino mass hierarchy
- Cosmological constraints on non-cold dark matter from DESI DR2 measurements
BibTeX
@misc{forerosanchez2026cosmological,
title = {{Cosmological constraints from the DESI DR1 Bispectrum Full-Shape and DR2 BAO}},
author = {D. Forero-Sánchez and S. Novell-Masot and H. Gil-Marín and L. Verde and J. Aguilar and S. Ahlen and D. Bianchi and A. Brodzeller and D. Brooks and F. J. Castander and S. Cole and A. de la Macorra and J. Della Costa and Biprateep Dey and P. Doel and S. Ferraro and A. Font-Ribera and J. E. Forero-Romero and Satya Gontcho A Gontcho and G. Gutierrez and C. Hahn and H. K. Herrera-Alcantar and K. Honscheid and D. Huterer and M. Ishak and D. Kirkby and A. Kremin and O. Lahav and C. Lamman and M. Landriau and L. Le Guillou and M. E. Levi and M. Manera and A. Meisner and R. Miquel and J. Moustakas and S. Nadathur and J. A. Newman and G. Niz and N. Palanque-Delabrouille and W. J. Percival and F. Prada and I. Pérez-Ràfols and G. Rossi and L. Samushia and E. Sanchez and D. Schlegel and M. Schubnell and J. Silber and G. Tarlé and B. A. Weaver},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.23936},
eprint = {2606.23936},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.23936},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Cosmological constraints from the DESI DR1 Bispectrum Full-Shape and DR2 BAO
AU - D. Forero-Sánchez
AU - S. Novell-Masot
AU - H. Gil-Marín
AU - L. Verde
AU - J. Aguilar
AU - S. Ahlen
AU - D. Bianchi
AU - A. Brodzeller
AU - D. Brooks
AU - F. J. Castander
AU - S. Cole
AU - A. de la Macorra
AU - J. Della Costa
AU - Biprateep Dey
AU - P. Doel
AU - S. Ferraro
AU - A. Font-Ribera
AU - J. E. Forero-Romero
AU - Satya Gontcho A Gontcho
AU - G. Gutierrez
AU - C. Hahn
AU - H. K. Herrera-Alcantar
AU - K. Honscheid
AU - D. Huterer
AU - M. Ishak
AU - D. Kirkby
AU - A. Kremin
AU - O. Lahav
AU - C. Lamman
AU - M. Landriau
AU - L. Le Guillou
AU - M. E. Levi
AU - M. Manera
AU - A. Meisner
AU - R. Miquel
AU - J. Moustakas
AU - S. Nadathur
AU - J. A. Newman
AU - G. Niz
AU - N. Palanque-Delabrouille
AU - W. J. Percival
AU - F. Prada
AU - I. Pérez-Ràfols
AU - G. Rossi
AU - L. Samushia
AU - E. Sanchez
AU - D. Schlegel
AU - M. Schubnell
AU - J. Silber
AU - G. Tarlé
AU - B. A. Weaver
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2606.23936
UR - https://arxiv.org/abs/2606.23936
AB - We present cosmological constraints from DESI DR1 full-shape measurements, including the LRG bispectrum, combined with DESI DR2 BAO data. The analysis accounts for cross-covariance using mocks, while ShapeFit compression mitigates prior volume effects in beyond-ΛCDM analyses. In ΛCDM, the DESI1.5 (P+B) analysis yields σ_8=0.868±0.026 and S_8=0.880±0.028, compared with σ_8=0.822±0.034 and S_8=0.827±0.036 in the previous power-spectrum-only analysis. The marginalized uncertainties are reduced by 24% and 22%, respectively. For w_0w_aCDM, DESI-only analyses with the bispectrum shift dark energy parameters toward ΛCDM, consistent with a cosmological constant within 1σ in the w_0--w_a plane. Adding CMB creates a preference for evolving dark energy: DESI+CMB (P+B) shows a 2.8σ deviation from ΛCDM. Including DES-Dovekie supernovae alone reduces this to 1.6σ, while the full combination gives 3.1σ. The bispectrum weakens evidence for time-varying dark energy relative to power-spectrum-only analyses. It also enhances sensitivity to massive neutrinos: in DESI-only data, the power-spectrum-only posterior for ∑ m_ν is consistent with zero, whereas adding the bispectrum yields 0.26±0.18 eV and a 95% upper limit of $0.59$ eV, shifting the peak into the positive region. For modified gravity, the bispectrum constrains μ_0 = 0.12±0.51 from DESI-only data, consistent with general relativity.
ER -