April 1, 2022
Two astrophysicists who have been selected for the prestigious NASA Hubble Fellowship Program (NHFP) have chosen to join the University of Chicago Kavli Institute for Cosmological Physics (KICP) to conduct their postdoctoral research. The Fellows are Jessica Avva and Hayley Macpherson.
The NHFP program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development. Nearly 450 applicants vied for the 2022 fellowships, and 24 were selected. Each fellowship provides the awardee up to three years of support.
Once selected, Fellows are named to one of three sub-categories corresponding to three broad scientific questions NASA seeks to answer about the universe:
How does the universe work? – Einstein Fellows
How did we get here? – Hubble Fellows
Are we alone? – Sagan Fellows
KICP’s incoming Fellows will seek to answer how the universe works as Einstein Fellows, beginning their programs in Autumn Quarter of 2022.
"From the quest for the first galaxies to the hunt for habitable exoplanets, this year's NASA Hubble Fellows seek answers to some of the most critical questions about our universe," said Paul Hertz, Astrophysics Division director at NASA Headquarters in Washington, D.C. "This is an incredibly promising group of young scientists, and I can't wait to see where their research takes them from here."
“NHFP postdoctoral fellows are future leaders in the field,” said KICP director, Professor Edward “Rocky” Kolb. “We are thrilled and proud that they chose Chicago to further their career. At KICP they will find amazing colleagues, facilities, and projects. Most importantly, they will be immersed in a vibrant research culture.”
Jessica Avva, Physics AB’15, grew up near Atlanta, Georgia. She got her start in astrophysics at the University of Chicago, where she worked with Assoc. Prof. Abigail Vieregg’s group on instrumentation and site characterization for radio detection of ultra-high energy astrophysical neutrinos. She completed a senior thesis on the characterization of atmosphere at the South Pole for the BICEP collaboration.
Since then, she has been a graduate student at the University of California, Berkeley, and will graduate with a Ph.D. in physics in the summer of 2022.
Avva’s research centers on understanding cosmic acceleration. In graduate school, she focused on probing inflation by mapping the oldest light in the universe with Cosmic Microwave Background (CMB) experiments. This work involved improving instrumental noise performance and developing novel data analysis techniques to optimize the inflationary constraints of the South Pole Telescope on large angular scales.
As an Einstein Fellow, Avva will bring her expertise in mm-wave instrumentation and data analysis to the University of Chicago to build experiments that can pioneer the technique of Line Intensity Mapping. These experiments will constrain cosmology by mapping the evolution of Large-Scale Structure over time. This will fill in the gap in cosmic history between the CMB and near-time optical measurements and lead to new constraints on dark energy, inflation, and beyond.
“Jessica Avva will contribute to ongoing projects studying CMB, such as the South Pole Telescope and the Atacama Cosmology Telescope located in Chile,” Kolb said. “She will also have the opportunity to develop new instruments for future exploration of the CMB. Chicago is recognized as a world leader in general relativity and early-universe cosmology, and we are pleased she is returning.”
"I can't wait to reintegrate into the KICP community," Avva said. "It's going to be great these next few years working with old and new collaborators to forward our understanding of the early universe!"
Hayley Macpherson grew up in Melbourne, Australia, where she completed her undergraduate studies in astrophysics at Monash University. She received her Ph.D. in 2019, also from Monash, supervised by Professor Daniel Price and Professor Paul Lasky. Since then, she has been a Herchel Smith Fellow in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge.
Macpherson is interested in learning about the effects of nonlinear general relativity in cosmology. During her doctoral studies, she led one of the first groups to use numerical relativity for cosmological simulations of large-scale structure formation. Usually, cosmological simulations and analysis of observations involve simplifying assumptions such as Newtonian dynamics or a homogeneous and isotropic spacetime expansion. While these assumptions have been invaluable in building modern cosmology, some disagreements between theory and observation are coming to light as our data gets more precise. Additionally, some aspects of the standard cosmological model remain physically unexplained.
As an Einstein Fellow, Macpherson will study cosmological observables in a numerical framework which is free from common simplifying assumptions. She hopes to find out whether using nonlinear general relativity in our cosmological modeling can help improve our understanding of the universe.
“Hayley Macpherson will explore new theoretical connections between general relativity and cosmology, and will also work with observers to connect her results to Chicago’s observational program,” Kolb said.
“I am super excited about starting my new research program at KICP,” Macpherson said. “It’s the perfect place for me to learn as much as I can about cosmological observables to be able to make accurate predictions from my simulations.”