RUI: Exploring Asymmetric Dark Universes

Whitman College, Walla Walla WA

Investigators

Abstract

This award funds the research activities of Professor Moira Gresham at Whitman College. Astrophysical measurements indicate that most of the matter in the Universe is composed of an unknown form of matter that we call "dark matter". Observational evidence indicates that our current understanding of elementary particles cannot account for it; most dark matter is not composed of protons, neutrons, and electrons like the "normal matter" whose building blocks we understand well. Uncovering the nature of dark matter will help us to better understand the contents of the cosmos and how our galaxy and solar system came to be. An understanding of the identity of dark matter may also help to revolutionize our model of the building blocks of all matter. Research into the nature of dark matter will thus advance the national interest by promoting the progress of fundamental physical science. The road to understanding the nature of dark matter will involve the synthesis of observations from a wide variety of particle and astrophysics experiments. In order to derive meaning from observations --- especially when they come in diverse forms --- it is critical to understand the theoretical possibilities for dark matter and their associated phenomenologies. In her research, Professor Gresham will investigate a compelling class of possibilities for dark matter that are also related to the currently unexplained fact that the vast majority of normal matter is in the form of particles rather than an equal share of both particles and anti-particles. Professor Gresham's research activities will also have significant broader impacts. They will enhance undergraduate education through direct involvement of undergraduates in her research and will increase her ability to make exciting contemporary particle astrophysics and cosmology topics accessible to undergraduates. Professor Gresham will also help to increase the participation of women in physics through her mentoring of undergraduate women and girls in the community. Finally, she will help to increase science literacy in her rural community by engaging in science outreach to the public schools. More technically, Professor Gresham will investigate the astrophysics and cosmology of dark-matter sectors with a matter/anti-matter asymmetry mirroring the matter/anti-matter asymmetry in the visible matter sector. A distinctive possibility within such asymmetric dark matter (ADM) models is the clumping or collection of dark matter in other astrophysical objects; by contrast, symmetric dark matter tends to annihilate (particle with anti-particle) in such circumstances. Professor Gresham will begin by investigating a class of ADM models in which the formation of bound states of ADM may have rich implications for the formation of structures (e.g., galaxies and stars) in the universe. Comparison of theoretical models to a diverse set of observations, including possibly observations of gravitational waves, will be necessary.