Professor Tessa Baker
Summary
I'm a cosmologist, working with both gravitational waves and electromagnetic observations to probe the fundamental laws of our universe. Much of my research centres around testing the laws of gravity that govern the largest cosmological scales, as a route to understanding the apparent dark sectors of our universe (dark energy, potentially dark matter).
Research interests
Here are some of the key focus areas of my current research program:
- Development of bright and dark gravitational wave sirens methods. These are two of leading methods we can extract cosmological parameters and test large-scale gravitational laws with gravitational waves.
- Novel techniques to complete galaxy catalogues. Galaxy surveys are a key ingredient of the dark sirens technique mentioned above, but they miss lots of faint galaxies. Reconstructing these `invisible' galaxies allows us to maximise the cosmology we can do with gravitational wave detections.
- Cosmological simulations in theories of gravity beyond GR. Simulations are essential for modelling the smaller (nonlinear) scales of the cosmic web. However, these simulations are only available in General Relativity and a handful of other well-studied models. My group is developing a new, flexible simulation code called Hi-COLA which can evolve the universe under a much broader set of gravity models.
- Gravitational wave astronomy is still a relatively new field. I'm particularly interested in understanding how to best combine these new observations with `traditional' electromagnetic surveys. Since the two kinds of data contain complementary information, we can maximise our cosmological results by jointly inferring constraints from both sets simultaneously.
I carry out some of the above research in collaboration with major telescopes and gravitational wave facilities. I am a member of the LIGO Scientific Collaboration, LISA, the Vera Rubin Observatory and Euclid.
Research outputs
2026
Exploring future synergies for large-scale structure between gravitational waves and radio sources
Zazzera, S., Fonseca, J., Baker, T., Clarkson, C.
1 Mar 2026, In: Monthly Notices of the Royal Astronomical Society. 547, 1, 12p.
Research output: Article
Black Hole Spectroscopy and Tests of General Relativity with GW250114
Abac, A. G., Abouelfettouh, I., Acernese, F., Ackley, K., Adamcewicz, C., Adhicary, S., Adhikari, D., Adhikari, N., Adhikari, R. X., Adkins, V. K., Afroz, S., Agapito, A., Agarwal, D., Agathos, M., Aggarwal, N.,
30 Jan 2026, In: Physical Review Letters. 136, 4, 26p., 041403
Research output: Article
Multimessenger lensing time delay as a probe of the graviton mass
Colangeli, E., Dalang, C., Baker, T.
30 Jan 2026, In: Physical Review D. 113, 2, 13p., 024067
Research output: Article
Large scale structure prior knowledge in the dark siren method
Dalang, C., Fiorini, B., Baker, T.
22 Jan 2026, In: Journal of Cosmology and Astroparticle Physics. 2026, 01, 30p., 034
Research output: Article
Cosmic Cartography II: completing galaxy catalogs for gravitational-wave cosmology
Leyde, K., Baker, T., Enzi, W.
5 Jan 2026, In: Journal of Cosmology and Astroparticle Physics. 2026, 1, 46p., 013
Research output: Article
2025
The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
Di Valentino, E., Said, J. L., Riess, A., Pollo, A., Poulin, V., Gómez-Valent, A., Weltman, A., Palmese, A., Huang, C. D., Bruck, C. v. d., Saraf, C. S., Kuo, C. Y., Uhlemann, C., Grandón, D., Paz, D.,
1 Sep 2025, In: Physics of the Dark Universe. 49, 263p., 101965
Research output: Article
A bright future? Prospects for cosmological tests of GR with multimessenger gravitational wave events
Colangeli, E., Leyde, K., Baker, T.
23 May 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 5, 32p., 078
Research output: Article
Multi-messenger gravitational lensing
Smith, G. P., Baker, T., Birrer, S., Collins, C. E., Ezquiaga, J. M., Goyal, S., Hannuksela, O. A., Hemanta, P., Hendry, M. A., Janquart, J., Keitel, D., Levan, A. J., Lo, R. K. L., More, A., Nicholl, M.,
1 May 2025, In: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences. 383, 2295, p. 1-63, 63p., 20240134
Research output: Article
Gravitational waves and galaxies cross-correlations: a forecast on GW biases for future detectors
Zazzera, S., Fonseca, J., Baker, T., Clarkson, C.
4 Feb 2025, In: Monthly Notices of the Royal Astronomical Society. 537, 2, p. 1912-1923, 12p.
Research output: Article
2024
Magnification and evolution bias of transient sources: GWs and SNIa
Zazzera, S., Fonseca, J., Baker, T., Clarkson, C.
20 May 2024, In: Journal of Cosmology and Astroparticle Physics. 2024, 05, 31p., 095
Research output: Article