Early Structure Formation with Cosmic Strings

• Hao Jiao (IBS CTPU-CGA)

Room: B438 bstract: Recent observations from the James Webb Space Telescope have revealed an unexpectedly high abundance of massive galaxies at very high redshifts, challenging the standard ΛCDM cosmological framework. Cosmic strings, which can act as nonlinear seeds in the early Universe, provide a promising explanation for this tension. In this talk, I will present our recent work on the impact of cosmic strings on early structure formation and how they may account for JWST high-redshift galaxies.

Couplings between matter currents and torsion in Einstein-Cartan gravity

• Minxi He (IBS CTPU-PTC)

Room: B438 Einstein-Cartan (EC) gravity is a natural generalization of general relativity (GR), allowing non-vanishing torsion. It is equivalent to GR when only the Einstein-Hilbert term is considered, while it exhibits distinct features if we include matter couplings. In particular, it is intriguing to study EC gravity in cosmology and find the observational constraints. In this talk, I will introduce the basics of EC gravity and some examples of inflation models constructed in the EC framework. Then, I will show different types of matter currents coupled with torsion in concrete examples and discuss the implications.

Tea Time with light meal Room: B438