Afternoon of Astrophysics

For almost three decades we have known that the expansion of the Universe is accelerating. This discovery came as a surprise: gravity was expected to slow cosmic expansion, not speed it up. Since then, the phenomenon has been firmly established and is usually explained by invoking a constant, exotic form of dark energy known as the cosmological constant, Λ. Together with dark matter—the unseen, clustering form of matter that shapes galaxies and cosmic structure—this leads to an extraordinarily successful and predictive model of the Universe: the Λ Cold Dark Matter, or ΛCDM, model.

In recent years, however, cracks have begun to appear in this picture. Intriguing inconsistencies in measurements of the Universe’s expansion rate suggest that our model may be incomplete. Even more recent observations hint that the cosmological constant may not fully account for cosmic acceleration, raising the possibility that a more dynamic form of dark energy is at work. Cosmology is once again entering a period of flux and uncertainty.

Professors David Alonso and Pedro Ferreira will share their perspectives on the current state of the Universe, reviewing and assessing the latest data. They will then be joined by their colleague Professor Maria Vicenzi for a panel discussion hosted by Professor Adrianne Slyz. Together they will explore what this uncertainty means, what the future of cosmology may hold, and how we can make sense of a Universe that continues to defy expectations.

This event invites you to the forefront of one of the most exciting and rapidly evolving areas of modern astrophysics.