Online Seminar “Dipole ΛCDM model- Towards a realistic model building in dipole cosmology”

Star-UBB Seminar Series:- Dipole ΛCDM model- Towards a realistic model building in dipole cosmology

Dipole cosmology is the maximally Copernican generalization of the Friedmann-Lemaître-Robertson-Walker(FLRW) paradigm that can incorporate bulk flows in the cosmic fluid. In this paper, the speaker and his team first discuss how multiple fluid components with independent flows can be realized in this set up. This is the necessary step to promote “tilted” Bianchi cosmologies to a viable framework for cosmological model building involving fluid mixtures (as in FLRW). They present a dipole Λ-Cold Dark Matter(ΛCDM) model which has radiation and matter with independent flows, with (or without) a positive cosmological constant. A remarkable feature of models containing radiation (including dipole ΛCDM) is that the relative flow between radiation and matter can increase at late times, which can contribute to e.g., the Cosmic Microwave Background(CMB) dipole. This can happen generically in the space of initial conditions. We discuss the significance of this observation for late time cosmic tensions.

時間:2024.03.28(四) 17:00~18:00
頻道:Zoom ID:853-7454-4159 ←
講者:Shahin Sheikh-Jabbari (IPM*, Tehran, Iran)


*پژوهشگاه دانشهای بنیادی

Scientific and Technological Advanced Research- Babeș-Bolyai University(Star-UBB) Seminar Series in Gravitation, Cosmology and Astrophysics

Presently a period of rapid and intense change are being witnessed in our understanding of the gravitational force, at a rate that is quickly increasing since the important observational discoveries of the late 1990s. With the advent of new observational techniques, the emergence of important cosmological and astrophysical paradigms can be seen that lead to a deep change in our understanding of the Universe. Astronomical observations strongly suggest that at large scales the force of gravity may not behave according to standard general relativity, and that a generalization of the gravitational action, either at the geometric level, or at the matter level, may be required for a full understanding of the gravitational interaction.

The goal of the present seminar is to bring Theoretical Gravitational Physics closer to the observations and experiments, and to discuss current topics in general relativity, high-energy physics, astrophysics and cosmology.


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