Chihway Chang
University of Chicago, IL·Astronomy & Astrophysics
Most matter in the universe is dark matter, which cannot be seen directly, yet how matter is spread across space reveals what the universe is made of and how it evolved. One clue is gravitational lensing, the bending of light by gravity, which maps unseen mass.
- Fields
Astronomy & Astrophysics
Physics
- Topics
cosmology
dark matter
dark energy
- Grants
- 2 known grants, through Aug 2027
What they work on
- Measure cross-correlations between CMB lensing, galaxy positions, galaxy lensing and the thermal Sunyaev-Zel'dovich effect using DES, SPT and ACT data, to tighten constraints on the universe's properties.
- Use the combined probes to assess whether the S8 tension challenges the standard cold dark matter model, and test alternative cosmological models.
- Scale up a field-level inference pipeline based on differentiable simulations to model galaxy weak lensing at the volume and resolution needed for real survey data.
- Add the thermal Sunyaev-Zel'dovich effect and observational effects to the simulations, then apply them to DES lensing and SPT-3G maps to constrain how baryonic gas is distributed.
More about the research
Measurements of today's matter distribution from galaxy surveys hint at a mismatch with predictions from the early universe under the standard cosmological model, a mismatch called the S8 tension. These projects ask whether that tension signals new physics or errors in measurement and modeling.
Why it matters
This work could show whether the standard picture of dark matter and dark energy holds or needs revision, by checking if the S8 tension reflects new physics or modeling errors. Better models of cosmic gas and combined analyses could also sharpen results from future surveys. The projects include data-science and AI teaching tools for high school and college students in Chicago and Honolulu.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Tristan Smith
Swarthmore College, PA·Astronomy & Astrophysics
Determine the theory space available to extensions of LCDM, the standard cosmological model, by identifying which model properties are required to resolve the disagreements in the measured expansion rate and matter clustering.
Soubhik Kumar
Tufts University, MA·Physics
Use effective field theory to classify the non-Gaussian signatures, unusual statistical patterns, left by heavy beyond-Standard-Model particles produced during inflation, and build templates for searches in cosmic microwave background (CMB) surveys.
Dragan Huterer
University of Michigan, MI·Astronomy & Astrophysics
Develop a method to measure the Hubble constant by cross-correlating gravitational-wave dark sirens with galaxy distributions. Dark sirens are merger events with no detected light.
The school
University of Chicago: 39 labs on PI Pages, $681M a year on research, 457 research doctorates a year.
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