As part of L'Automne de la science dans les bibliothèques - La tête dans les étoiles and the cycle, " Collège de France : faire connaissance ! ", the Bibliothèque historique de la Ville de Paris (BHVP) will welcome Françoise Combes, Professor Emeritus at the Collège de France, for a lecture on " The dark sector of the Universe " on Thursday, October 9 , 2025 at 7:00 pm .
Over 95 % of the Universe's content is black or unknown. Over the last few decades, we have discovered that 25 % of this content is made up of exotic dark matter, particles that do not belong to the Standard Model. This matter is only detected by its gravitational action, stabilizing galaxies and clusters of galaxies. What's more, we've known for twenty-five years that the expansion of the Universe is accelerating, due to dark energy, which accounts for 70 % of it. We will review the possible candidates for these exotic particles, and even theories of modified gravity. Dark energy could just be a cosmological constant, but it could also be a fifth element or quintessence, evolving dynamically over time. The Euclid satellite, launched in July 2023 by the European Space Agency, will observe a large part of the sky, and identify more than ten billion galaxies at different epochs. It will use several tools, such as gravitational lenses, baryonic acoustic oscillations, the rate of growth of structures, galaxy clusters and their space distortions, and thus lift the veil on the dark sector of the Universe.
This event is part of the " Collège de France: get to know us! "cycle , developed with the City of Paris library network.
