Dr Seshadri Nadathur
Summary
I am Associate Professor in Cosmology and an Ernest Rutherford Fellow at the Institute of Cosmology and Gravitation. My research area is observational cosmology – this means I study the properties of dark energy, dark matter and gravity, using the large-scale structure of the Universe and based on galaxy survey data collected by the leading ground-based and space telescopes.
My research is funded by the Science and Technology Facilities Council (STFC) and previously by the European Commission.
Research interests
I study the large-scale structure of the Universe, analysing the statistical patterns in the clustering of millions of galaxies to uncover cosmological information. I work on redshift-space distortions, baryon acoustic oscillations, gravitational lensing and cross-correlations with the cosmic microwave background anisotropies, and I am particularly interested in the use of new cosmological probes beyond two-point clustering statistics, such as cosmic voids or density-split statistics.
A large fraction of my work involves the Dark Energy Spectroscopic Instrument survey, or DESI. DESI is a 5-year spectroscopic survey programme to map the positions of 40 million galaxies and quasars in order to determine the dark energy equation of state, the neutrino mass scale, and a host of other science results. I have led the Galaxy and Quasar Clustering working group in DESI since 2022.
Another large part of my work is within the Euclid Consortium. Euclid is a space telescope, launched in 2023, which combines spectroscopic measurements of around 30 million galaxies with weak lensing and photometric surveys of over a billion. I am the PI of a UK Space Agency grant at Portsmouth funding our work on the Euclid Science Ground Segment infrastructure development, and lead a group creating the spectroscopic galaxy catalogues and visibility mask for clustering science. I am also coordinator for a Key Project on measuring baryon acoustic oscillations.
In the past I also worked on the extended Baryon Oscillation Spectroscopic Survey (eBOSS) and the Dark Energy Survey (DES).
Research outputs
2026
Modelling the impact of quasar redshift errors on the full-shape analysis of correlations in the Lyman-α forest
Gordon, C., Cuceu, A., Font-Ribera, A., Herrera-Alcantar, H. K., Aguilar, J. N., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Cole, S., Macorra, A. d. l., Dey, B., Doel, P., Forero-Romero, J. E.,
1 Jan 2026, In: Monthly Notices of the Royal Astronomical Society, 19p., staf2035
Research output: Article
2025
The Lyman-α Forest from LBGs: First 3D Correlation Measurement with DESI and Prospects for Cosmology
Herrera-Alcantar, H. K., Armengaud, E., Yèche, C., Gordon, C., Casas, L., Font-Ribera, A., Magneville, C., Ravoux, C., Aguilar, J., Ahlen, S., Anand, A., Brooks, D., Chaussidon, E., Claybaugh, T., Cuceu, A.,
22 Dec 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 12, 38p., 053
Research output: Article
DESI Spectroscopy of HETDEX Emission-line Candidates I: Line Discrimination Validation
Landriau, M., Cooper, E. M., Davis, D., Gebhardt, K., Ciardullo, R., Armengaud, É., Dey, A., Raichoor, A., Schlegel, D. J., Aguilar, J., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Macorra, A. d. l.,
19 Dec 2025, In: The Astrophysical Journal. 995, 2, 13p., 220
Research output: Article
Euclid preparation: LXXVI. Simulating thousands of Euclid spectroscopic skies
Collaboration, E., Monaco, P., Parimbelli, G., Elkhashab, M. Y., Salvalaggio, J., Castro, T., Lepinzan, M. D., Sarpa, E., Sefusatti, E., Stanco, L., Tornatore, L., Addison, G. E., Bruton, S., Carbone, C.,
17 Dec 2025, In: Astronomy and Astrophysics. 704, 19p., A306
Research output: Article
Study of the Connected Four-Point Correlation Function of Galaxies from DESI Data Release 1 Luminous Red Galaxy Sample
Hou, J., Cahn, R. N., Aguilar, J., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Doel, P., Ferraro, S., Forero-Romero, J. E., Gaztañaga, E., Guillou, L. L., Gutierrez, G., Honscheid, K., Huterer, D.,
15 Dec 2025, In: Physical Review D. 112, 25p., 122005
Research output: Article
Galaxy-Multiplet Clustering from DESI DR2
Wang, H., Eisenstein, D. J., Aguilar, J. N., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Macorra, A. d. l., Dey, A., Dey, B., Doel, P., Ferraro, S., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E.,
2 Dec 2025, In: Monthly Notices of the Royal Astronomical Society
Research output: Article
A joint analysis of 3D clustering and galaxy x CMB-lensing cross-correlations with DESI DR1 galaxies
Maus, M., White, M., Sailer, N., Lizancos, A. B., Ferraro, S., Chen, S., DeRose, J., Aguilar, J., Ahlen, S., BenZvi, S., Bianchi, D., Brooks, D., Burtin, E., Castander, F. J., Chaussidon, E., Claybaugh, T.,
24 Nov 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 11, 44p., 077
Research output: Article
DESI DR1 Lyα 1D power spectrum: The Fast Fourier Transform estimator measurement
Ravoux, C., Abdul-Karim, M., Goff, J. L., Armengaud, E., Aguilar, J. N., Ahlen, S., Bailey, S., Bianchi, D., Brodzeller, A., Brooks, D., Chaves-Montero, J., Claybaugh, T., Cuceu, A., de Belsunce, R.,
24 Nov 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 11, 42p., 079
Research output: Article
Modeling of the High Column Density systems in The Lyman-Alpha Forest
Tan, T., Chaussidon, E., Goff, J. M. L., Balland, C., Armengaud, E., Aguilar, J., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Cuceu, A., Macorra, A. d. l., Doel, P., Forero-Romero, J. E., Gaztañaga, E.,
24 Nov 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 11, 35p., 074
Research output: Article
Enhancing DESI DR1 Full-Shape analyses using HOD-informed priors
Zhang, H., Bonici, M., Rocher, A., Percival, W. J., de Mattia, A., Aguilar, J. N., Ahlen, S., Alves, O., Aviles, A., Lizancos, A. B., Bianchi, D., Brooks, D., Cuceu, A., Macorra, A. d. l., Doel, P., Ferraro, S.,
14 Nov 2025, In: Journal of Cosmology and Astroparticle Physics. 2025, 11, 36p., 049
Research output: Article