1. Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe

2. Shrimp Nebula© VLT, European Space Observatory Convince you all of the existence of dark matter Review how one can catch dark matter Plan

3. ©2000, 2001 B Katzung, Andromeda galaxy

4. 4 Universe content

7. © NASA, Orion nebula Dark energy: Discovered in 1998 while studying the relative speeds of galaxies The Universe expansion is accelerating A completely unknown type of energy must be causing this expansion Physics Nobel Prize in 2011 went to Saul Perlmutter, Brian Schmidt and Adam Riess

8. 8 Universe content

11. What is generating the gravitational pull needed to maintain these galaxies together?

12. 12 Dark matter provides the gravitational force needed to maintain these galaxies together

13. Mais comment mesure-t-on la composition de lUnivers?

14. 1 second Protons and neutrons form 380 000 years Atoms form 1 billion years Stars and galaxies form 13.7 billion years 2.7 degrees 10 32 degrees The Big Bang

15. Stars and Dust Across Corona Australis © Ignacio Diaz Bobillo Rayonnement fossile The Universe became transparent 380 000 years after the Big Bang The photons present then are still moving around freely But the Universe expanded and they cooled down We still observe them today in the form of microwave background at 2.725 degrees Kelvin

16. Cosmological microwave background

17. Width and temperature of each lump ( or angular spectrum measured by Planck) Angular width of all structures observed in the Universe Temparature fluctuations in (μ K)

18. Big Bang Standard Model Λ-CDM model: a model with 6 free parameters including Ω d : dark matter density Ω Λ : dark energy density

19. 19 ΩΛΩΛ

20. How did the Universe evolve from an immense fog of free particles… …to an Universe filled with stars and galaxies?