Unraveling Dark Energy

Although dark energy makes up about 70% of our universe, it remains one of the greatest mysteries of modern physics. Unraveling its nature is the central mission of the Dark Energy Spectroscopic Instrument (DESI), a flagship cosmology program led by Lawrence Berkeley National Laboratory. By constructing the largest three-dimensional map of the universe ever created, DESI traces the evolution of dark energy across 12 billion years of cosmic history.

Results published since 2024 reveal a growing tension with the standard model where dark energy is described by a cosmological constant, challenging the paradigm established over the past three decades. DESI’s findings were recognized by Time Magazine as one of the “top discoveries” of 2024 and are reshaping our understanding of the universe. In this presentation, Dr. Palanque-Delabrouille will provide an overview of our current knowledge of dark energy, explain how we study it, and discuss the implications of DESI’s latest results.

Speaker: Nathalie Palanque-Delabrouille, Lawrence Berkeley National Lab