Jahmour Givans

Cotsen Postdoctoral Fellow in the Society of Fellows
Presidential Postdoctoral Research Fellow in the Department of Astrophysical Sciences
2022-2025 Cohort

Jahmour Givans is interested in understanding how the contents and structure of the universe, at the largest physical scales we can explore, have evolved over time. To do this, he uses a combination of theoretical modeling, simulations, computations, and data analysis to describe astronomical systems. He holds a Ph.D. in Physics from The Ohio State University and an Sc.B. in Astrophysics from Brown University.

One of the principal questions in physical cosmology, his area of expertise, is whether the standard model of cosmology, the “Lambda-cold dark matter (LCDM) model,” is an accurate description of nature. LCDM has been regarded as the most successful cosmological model for over two decades, but it is not without flaws. Among the problems with LCDM are: Why does the expansion rate inferred from the early universe disagree with what we measure today? Why do the amounts of measured matter clustering measured at early and at late times disagree? What is the source of anomalies we see in the cosmic microwave background? Whether these problems can be explained by errors in our measurements or whether they are indicative of new physics is a topic of great contention.

Givans works on better modeling physical systems and their potential sources of error so that researchers can be more confident in the accuracy and precision of their measurements. He has applied his modeling to systems that will be explored in ongoing and upcoming cosmological experiments including the Dark Energy Spectroscopic Instrument, the Prime Focus Spectrograph, and the Nancy Grace Roman Space Telescope. He is currently interested in combining data from large-scale structure experiments and cosmic microwave background experiments to constrain cosmological parameters and models.