Hierarchical Gaussian-process reconstruction of late-time expansion with DESI BAO and compressed Planck priors

Yu-Hao Mu, Zhihuan Zhou, Enkun Li

We reconstruct the late-time expansion history with a hierarchical Gaussian process (GP) that co-samples the kernel hyperparameters $({\sigma }_f,l)$ together with $(\Hzero,\Om,\Ok,ω_b h^2…