A Novel Cosmological Probe and Model in Revealing Cosmic Tensions

In this thesis, we review the current cosmological crisis in the framework of the Lambda–cold dark matter model, which is observational inconsistencies between different probes, including Hubble tension, S8 tension, and dipole tension. In revealing the cosmic tensions, we propose a novel cosmological probe, cosmological standard timers, for a clear picture of cosmic tensions and a theoretical model, a Gpc-scale local void, as a potential solution of cosmic tensions. The cosmological standard timers can construct the redshift-time relation based on dynamical systems in the universe, and further constrain the cosmic evolution. Two kinds of standard timer candidates are proposed, which are primordial black hole (PBH) clusters and PBH binaries. By studying their intrinsic dynamics and obse...[ Read more ]