Research

My research focuses on Cosmic Dawn and the Epoch of Reionization. I primarily use computational methods, with applications to cosmological simulations, theoretical modeling, or data analysis. Here are some highlights of the type of work I’ve done in the past. For a list of my publications on NASA/ADS, please follow this link.

Cosmological Simulations

I have designed and run large-scale cosmological simulations of helium reionization, which included developing a model of populating volumes with sources self-consistently. I have also helped develop semi-numeric methods of galaxy formation for hydrogen reionization, and explored implications for upcoming observations of 21cm radiation. Currently I am the PI or co-PI of several XSEDE grants whose scientific goals include running a new suite of hydrogen reionization simulations.

Machine Learning

I make use of machine learning methods in both analyzing cosmological simulations and assuring data quality in telescope data. I have used convolutional neural networks (CNNs) to develop new methods for analyzing upcoming 21cm data. I have also applied CNNs to data from HERA to find radio frequency interference (RFI) events. I am also interested in approximate Bayesian neural networks as a way of defining robust error estimates when using machine learning techniques.

Cross-correlation

I have explored the possibility of cross-correlating upcoming 21cm data and CMB data to infer reionization properties. I was also a primary co-author of a white-paper on cross-correlation for the Astro2020 Decadal Survey on Astronomy and Astrophysics, emphasizing opportunities for cross-correlations in the coming decade of astronomy.

Processing “Big Data”

I am the principal developer of hera_opm, a package for easily defining workflows for data files and executing them efficiently. I am also a developer and current maintainer of the librarian, a package for long-term data storage and movement between computing facilities. Both of these systems work together to form the HERA Real-Time Processing system, an integral part of the experiment. The development of this infrastructure helped analyze some of the first data taken by the HERA telescope. I am also the principal developer of the UVH5 file format, an HDF5-based standard for storing interferometer visibility data for radio telescopes.