Conveners
Probing cosmology
- Daisuke Nagai (Yale University)
Probing cosmology
- Daisuke Nagai (Yale University)
We propose an 'iterative mean-field approach' to compute the solutions of the gravitational collapse dynamics. This approach iteratively searches for the evolution of the interaction field ϕ(t) - in this case the enclosed mass profile M(r, t) - that is consistent with the dynamics, thus that ϕ(t) is the fix-point of the iterative mapping, H(ϕ)=ϕ. The formalism replaces the N-body interactions...
Dark matter serves as the hidden framework shaping the universe, driving the formation, growth, and clustering of galaxies on cosmic scales. One key feature of dark matter halos, the splashback radius, represents a physical boundary that offers a more direct and fundamental description of halo structure compared to the traditional spherical overdensity approach. Using the deep, high-resolution...
Many of our strongest constraints on the cosmological model come from analysis of the Cosmic Microwave Background formed at high redshift in the early universe. Low-redshift cosmological tests are fundamentally important, however, as they test different regimes of time, scale and curvature. The abundance of galaxy clusters is one such test, constraining the product of the amplitude of...
Galaxy cluster abundance measurements provide a classic test of cosmology. However, they exhibit a strong degeneracy between the amplitude of density fluctuations σ8, and the matter density Ωm, as do other similar low-redshift tests such as cosmic shear. The mass distribution in the infall region around galaxy clusters, where material is being accreted from the surrounding field, exhibits an...
The turnaround scale represents the largest non-expanding boundary of a dark matter halo. It is sensitive to cosmology, behaving as an evolving standard ruler, and it imprints on the galaxy distribution around cluster centers. I will discuss how the turnaround feature can be identified in simulated observations, and how it can be exploited to devise novel cosmological tests
