In light of the large-scale anomalies in observations and tensions in cosmological parameters such as H0 and S8 in the age of precision cosmology, we formulated possible dark energy inhomogeneities as the random fluctuations on superhorizon scales, sourced by some light scalar field. Based on this model slightly breaking the cosmological principle, we discuss the possible impacts of the dark energy inhomogeneities on cosmological observables, such as the luminosity distance, the matter power spectrum, and the cosmic microwave background (CMB) anisotropies. Dark energy is a key target in the flagship surveys such as Euclid, LSST, Roman Spade Telescope, and CSST; and it is possible to detect or falsify dark energy inhomogeneities in these projects. This research serves as a preparation for the possibility. 

报告人简介    

Yue Nan is a postdoctoral researcher at Kavli Institute for the Physics and Mathematics of the Universe (IPMU), U. Tokyo. He received his PhD at Hiroshima University, receiving the JSPS Research Fellowships for Young Scientists. He works mainly on observational cosmology, recently focusing on phenomenological modeling of dark energy, exploring its possible inhomogeneities. His work and research interests also cover other directions such as the redshift-space distortions and primordial non-Gaussianity in the large-scale structure of the universe, and the quantum field theory on curved spacetime.

邀请人

皮石 副研究员