Conveners
Session 9 - Observational Cosmology
- Session convener: José Fonseca
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Javier de Cruz Pérez (Universidad de Córdoba)16/04/2025, 10:15Talk
The symmetry group of general relativity is the group of diffeomorphisms (Diff), which means that the form of the physical equations remains invariant under general coordinate transformations. We discuss the cosmological implications of breaking the Diff invariance down to transverse diffeomorphisms (TDiff) invariance in the matter sector. We show that even simple cases, like a minimally...
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Dr Ruchika Ruchika (University of Salamanca)16/04/2025, 10:30Talk
Observations from the James Webb Space Telescope (JWST) have unveiled an unexpectedly high abundance of massive galaxies at early times, further challenging ΛCDM predictions. I will discuss our pioneering solutions for these tensions and their implications for the future of cosmology.
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Adrià Gómez-Valent16/04/2025, 10:45Talk
The parameter $\sigma_8$, which represents the root-mean-square (rms) mass fluctuations on a scale of $R_8=8h^{-1}$ Mpc (where $h$ is the reduced Hubble parameter), is commonly used to quantify the amplitude of matter fluctuations at linear cosmological scales. Derived quantities, such as $S_8=\sigma_8(\Omega_m^{0}/0.3)^{0.5}$, are also frequently employed. However, the dependence of $R_8$ on...
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