الصدى الكوني: خريطة من 600 مليون مجرة تؤكد الطاقة المظلمة ✛

الملخص الأصلي

كما كتبه المؤلفون، بالإنجليزية arXiv:2607.19648v1

The physical origin of cosmic acceleration remains one of the central questions in modern cosmology. The integrated Sachs-Wolfe (ISW) and Rees-Sciama (RS) effects, which arise from the evolution of gravitational potentials, provide a dynamical test of cosmic acceleration. We measure the cross correlation between the Planck temperature map of the cosmic microwave background (CMB) and a foreground-free map of the $$100\,\mu\mathrm{m}$$ cosmic infrared background (CIB) from Y.-K. Chiang (2023), using the $$k$$-nearest neighbor cumulative distribution function ($$k$$NN-CDF). As the CIB map is reconstructed from $${\sim}600$$ million Wide-field Infrared Survey Explorer galaxies extending to $$z\approx2.5$$, the measurement is equivalent to a galaxy-CMB cross correlation. We find evidence for a positive cross correlation, rejecting the null hypothesis of no correlation at $$p=0.02~(2.3\sigma)$$ using the $$\chi^2$$ test. We further quantify its amplitude with $$A_{k\mathrm{NN}}$$, defined relative to an assumed cosmological model, and obtain $$A_{k\mathrm{NN}}=0.95\pm0.20~(4.8\sigma)$$ with respect to $$\Lambda\mathrm{CDM}$$ mock data including the ISW and RS effects. The $$k$$NN-CDF analysis improves the detection significance by $${\sim}20\%$$ over the two-point correlation function. We also explore evolving dark energy by constructing two tomographic maps from the full CIB map; the results are consistent with $$\Lambda$$CDM. Finer tomographic reconstruction of the CIB, for example from multiband data of SPHEREx, would further tighten constraints on evolving dark energy.