Particle Physics Seminar: Constraining Dark Energy from Local Universe

Abstract:

In this talk, we explore how the Cosmological Constant (Λ) can be constrained through the dynamics of the local Universe. By focusing on the Milky Way and Andromeda galaxies, we demonstrate that the ratio between the Keplerian period and TΛ≈35Gyr determines the significance of the effects from the Cosmological Constant. Given that the Andromeda-Milky Way orbit has a period of approximately 20 Gyr, the influence of dark energy becomes significant. Using the latest mass estimates for both galaxies, we find that the value of the Cosmological Constant based solely on Local Group dynamics is less than 5.44 times the value derived from Planck data. Additionally, we extend the Virial Theorem for galaxy groups in the local Universe, identifying which systems exhibit non-negligible local effects of dark energy. We also discuss the implications for these systems, such as increased predicted mass and the classification of virialized groups.

Based on: Phys.Lett.B 858 (2024) 139033,

Astrophys.J.Lett. 953 (2023) 1, L2,

Astron.Astrophys. 689 (2024) L1

Seminar Organizer: Dr. Michael Geller