###### "Superfluids and the Cosmological Constant Problem"

The observation that the cosmic expansion is accelerating suggests that the value of the cosmological constant is meV-scale. From a theoretical perspective, this value is fine-tuned, and the expectation is that it should be much larger. In this talk, I will describe recent progress towards resolving this "cosmological constant problem". In this proposal, the Universe is pervaded by a superfluid that can counteract the effects of an arbitrary cosmological constant. The superfluid can equivalently be viewed as a sector of Lorentz-violating massive gravity. I will explain how to construct stable theories, and their potential observational phenomenology. I will conclude by presenting some recent progress in constructing realistic cosmological models.

**About the speaker**

Jeremy is a theoretical physicist who is interested in understanding the nature of our universe using the interface of cosmology, gravitation, and astrophysics. He spends a lot of my time thinking about the biggest mysteries in modern physics, such as what is causing the expansion of the universe to accelerate, and why there is more matter than anti-matter. This has led Jeremy to study physics on many scales, from stars and galaxies, to black holes and gravitational waves, to the early universe.

More details on Jeremy can be found here.