In the report by BICEP/Keck collaborations, the tensor-to-scalar ratio is r₀. ₀₅<0. 036 (95\% C. L. ). However, recent datasets have preferred the evolving dark energy, which thus have significantly shifted the bestfit values of standard ΛCDM cosmological parameters. In this paper, we perform the joint analysis of BICEP/Keck cosmic microwave background (CMB) B-mode data, latest DESI DR2 baryon acoustic oscillations and supernova data, combined with Planck PR3 and PR4 CMB data respectively, and find r₀. ₀₅=0. 0159^+0. 0057-₀. ₀₁₄ and r₀. ₀₅=0. 0164^+0. 0063-₀. ₀₁₄. The constraints on r are further tightened compared to the result of BICEP/Keck collaborations. Though there might be still systematic uncertainties in B-mode measurements due to the foreground contamination, our work is to not say what the value of r is, but present the state-of-the-art constraints on r and emphasize that the detection for r depends potentially on our insight into the dark universe, highlighting the important role of cosmological surveys in comprehending our very early universe.
Wang et al. (Mon,) studied this question.