Cosmological Anomalies: a way to think about beyond both standard models of cosmology and particle physics

• Nima Khosravi (Department of Physics, Sharif University of Technology)

For years, we have been told we are in the golden era of cosmology due to very precise cosmological datasets. The standard model of cosmology (ΛCDM), which includes dark matter and dark energy, has been very successful and reliable phenomenologically, despite its theoretical puzzles. In recent years, however, new observations have emerged that appear incompatible with ΛCDM predictions. The Hubble tension (regarding the rate of cosmic expansion), the S₈ tension (concerning matter clustering), the large-scale anomalies in the CMB (challenging cosmological isotropy), and, most recently, findings from DESI (questioning the constancy of dark energy) may signal cracks in this successful model. In my view, we are now entering a different golden era—one defined not by confirmation, but by intriguing tensions. These persistent non-understandings open the door for new ideas and models. In this talk, I will briefly introduce and discuss these anomalies. Then, if time allows, I will share some of our own ideas for addressing them. I will conclude by suggesting that these cosmological anomalies could serve as a unique platform for exploring physics beyond the Standard Model of particle physics.