Current graduate student in cosmology
Joyce Byun is a graduate student in Astronomy working with Prof. Rachel Bean. Her primary research focus is on studying observable signatures of inflation and how the physical mechanism that caused inflation might be discovered through observational constraints.
Inflation, an early period of exponential expansion in the universe, has been a highly successful paradigm for describing the observed flatness and smoothness of the universe and explaining the initial density fluctuations which later collapsed to form the structures we see today (stars, galaxies, galaxy clusters). Though inflation can in general be produced by a wide variety of physical phenomena, they each have different predictions for the statistics of the fluctuations that were initially imprinted on the universe. Current observations of the cosmic microwave background show that the fluctuations are consistent with a Gaussian distribution, but with improved experiments and a better understanding of the viable theories that are available, it will be possible to detect small deviations from Gaussianity (non-Gaussianities) and thus put constraints on the physics of inflation.
Joyce is studying how well non-Gaussianities may be detected and distinguished using current and future observations of the cosmic microwave background and large-scale structure. She is particularly interested in how combining different observations may improve or degrade constraints on inflation when experimental realities and astrophysical effects are taken into account.
Joyce has been a teaching assistant for four introductory Astronomy courses at Cornell: Astro 2201 - The History of the Universe (Fall 2009), Astro 2202 - Our Home in the Solar System (Spring 2010), Astro 1101 - The Nature of the Universe (Fall 2010), and Astro 1102 - Our Solar System (Spring 2011). She has also fostered her teaching experience by enrolling in ALS 6015 - The Practice of Teaching in Higher Education (Spring 2012), a graduate-level course designed to prepare students for the teaching responsibilities of a faculty position.
Since joining Cornell Astronomy, Joyce has been actively involved in the Astronomy Grads Network as Vice-President (2011-12) and President (2012-13). She has also enjoyed participating in several outreach events: Curious? Ask an Astronomer, Ask an Astronomer podcasts, Museum in the Dark, Expanding Your Horizons, Look to the Future Career Day at Dewitt Middle School, and more.