Seshadri Nadathur | University of Portsmouth

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

DESI DR1 Ly$α$ 1D power spectrum: Validation of estimators

Karaçaylı, N. G., Ravoux, C., Martini, P., Goff, J. M. L., Armengaud, E., Abdul-Karim, M., Aguilar, J., Ahlen, S., Anand, A., BenZvi, S., Bianchi, D., Brooks, D., Claybaugh, T., Cuceu, A., Macorra, A. d. l., Dey, B., Doel, P., Ferraro, S., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gontcho, S. G. A., Gutierrez, G., Herrera-Alcantar, H. K., Honscheid, K., Ishak, M., Jimenez, J., Joyce, R., Kirkby, D., Kisner, T., Kremin, A., Lahav, O., Landriau, M., Guillou, L. L., Manera, M., Meisner, A., Miquel, R., Nadathur, S., Niz, G., Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Pérez-Ràfols, I., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Seo, H., Silber, J.

16 Apr 2026, In: Journal of Cosmology and Astroparticle Physics. 2026, 04, 32p., 048

Research output: Article

Signatures of a Tidally Induced Spiral Arm at the Anticenter of the Milky Way and a Kinematically Extended Anticenter Stream Using DESI DR2

Lambert, M., Rockosi, C. M., Koposov, S. E., Li, T. S., Valluri, M., Silva, L. B. e., Li, S., Amarante, J. A. S., Byström, A., Medina, G. E., Sandford, N. R., Najita, J., Kizhuprakkat, N., Aguilar, J. N., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Dawson, K., Macorra, A. d. l., Doel, P., Forero-Romero, J. E., Gaztañaga, E., Gontcho, S. G. A., Gutierrez, G., Joyce, D., Kremin, A., Lamman, C., Landriau, M., Guillou, L. L., Manera, M., Meisner, A., Miquel, R., Moustakas, J., Myers, A., Nadathur, S., Percival, W., Prada, F., Perez-Rafols, I., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Silber, J. H., Sprayberry, D., Tarle, G., Weaver, B. A., Zhou, R., Zou, H.

15 Apr 2026, In: The Astronomical Journal. 171, 5, 19p., 292

Research output: Article

Probing the environment around GW170817 with DESI: insights on galaxy group peculiar velocities for standard siren measurements

Amsellem, A. J., Palmese, A., Douglass, K., Howlett, C., Karp, J. S. M., Hernandez, I. M., Moustakas, J., Wechsler, R. H., Aguilar, J., Ahlen, S., Benzvi, S., Bianchi, D., Brooks, D., Carr, A., Claybaugh, T., Cuceu, A., Davis, T. M., Macorra, A. d. l., Dey, A., Dey, B., Doel, P., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gontcho, S. G. A., Gutierrez, G., Honscheid, K., Ishak, M., Joyce, R., Kehoe, R., Kisner, T., Kremin, A., Lahav, O., Lambert, A., Landriau, M., Guillou, L. L., Manera, M., Manwadkar, V., Meisner, A., Miquel, R., Myers, A. D., Nadathur, S., Niz, G., Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Pérez-Ràfols, I., Raichoor, A., Rossi, G.

14 Apr 2026, In: The Astrophysical Journal. 1001, 2, 19p., 157

Research output: Article

Data Release 1 of the Dark Energy Spectroscopic Instrument

Collaboration, D., Karim, M. A., Adame, A. G., Aguado, D., Aguilar, J., Ahlen, S., Alam, S., Aldering, G., Alexander, D. M., Alfarsy, R., Allen, L., Prieto, C. A., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Lizancos, A. B., Ballester, O., Bault, A., Bautista, J., BenZvi, S., Silva, L. B. e., Bermejo-Climent, J. R., Beutler, F., Bianchi, D., Blake, C., Blum, R., Canning, R., Findlay, N., Gaztañaga, E., Gil-Marín, H., Gonzalez-Perez, V., Graur, O., Gsponer, R., Howlett, C., Joudaki, S., Manera, M., Nadathur, S., Percival, W. J., Pieri, M. M., Ross, A. J., Ruggeri, R., Sabiu, C. G., Samushia, L., Tojeiro, R., Wang, M. S., Youles, S.

13 Apr 2026, In: The Astronomical Journal. 171, 5, 34p., 285

Research output: Article

AT2025ulz and S250818k: Leveraging DESI spectroscopy in the hunt for a kilonova associated with a sub-solar mass gravitational wave candidate

Hall, X. J., Palmese, A., O'Connor, B., Gruen, D., Busmann, M., Gassert, J., Hu, L., Hernandez, I. M., Aguilar, J. N., Amsellem, A., Ahlen, S., Banovetz, J., BenZvi, S., Bianchi, D., Brooks, D., Castander, F. J., Claybaugh, T., Cuceu, A., Dey, A., Doel, P., Faba-Moreno, J., Ferraro, S., Font-Ribera, A., Forero-Romero, J. E., Gutierrez, G., Guillou, L. L., Joyce, D., Kisner, T., Kremin, A., Lahav, O., Lamman, C., Landriau, M., Levi, M., Macorra, A. d. l., Manera, M., Meisner, A., Miquel, R., Moustakas, J., Nadathur, S., Prada, F., Perez-Rafols, I., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Sprayberry, D., Tarle, G., Weaver, B. A., Zhou, R., Zou, H.

9 Apr 2026, In: The Astrophysical Journal. 1001, 1, 15p., L20

Research output: Article

Euclid preparation: LXXXIX. Accurate and precise data-driven angular power spectrum covariances

Naidoo, K., Ruiz-Zapatero, J., Tessore, N., Joachimi, B., Loureiro, A., Aghanim, N., Altieri, B., Amara, A., Amendola, L., Andreon, S., Auricchio, N., Baccigalupi, C., Bagot, D., Baldi, M., Bardelli, S., Battaglia, P., Biviano, A., Branchini, E., Brescia, M., Camera, S., Capobianco, V., Carbone, C., Cardone, V. F., Carretero, J., Castellano, M., Castignani, G., Cavuoti, S., Chambers, K. C., Cimatti, A., Colodro-Conde, C., Congedo, G., Conversi, L., Copin, Y., Courbin, F., Courtois, H. M., Silva, A. D., Degaudenzi, H., Lucia, G. D., Dubath, F., Dupac, X., Dusini, S., Escoffier, S., Farina, M., Farinelli, R., Farrens, S., Percival, W. J., Gaztanaga, E., Joudaki, S., Nadathur, S.

8 Apr 2026, In: Astronomy and Astrophysics. 708, 20p., A167

Research output: Article

Euclid preparation: LXXXVIII. 3D reconstruction of the cosmic web with simulated Euclid Deep spectroscopic samples

Collaboration, E., Kraljic, K., Laigle, C., Balogh, M., Jablonka, P., Kuchner, U., Malavasi, N., Sarron, F., Pichon, C., Lucia, G. D., Bethermin, M., Durret, F., Fumagalli, M., Gouin, C., Magliocchetti, M., Sorce, J. G., Cucciati, O., Fontanot, F., Hirschmann, M., Kang, Y., Spinelli, M., Aghanim, N., Amara, A., Andreon, S., Auricchio, N., Baccigalupi, C., Baldi, M., Bardelli, S., Biviano, A., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Cañas-Herrera, G., Capobianco, V., Carbone, C., Carretero, J., Casas, R., Casas, S., Castander, F. J., Castellano, M., Castignani, G., Cavuoti, S., Chambers, K. C., Cimatti, A., Percival, W. J., Gaztanaga, E., Joudaki, S., Nadathur, S., Naidoo, K.

8 Apr 2026, In: Astronomy and Astrophysics. 708, 30p., A164

Research output: Article

$H_0$ Without the Sound Horizon (or Supernovae): A 2% Measurement in DESI DR1

Zaborowski, E. A., Taylor, P., Honscheid, K., Cuceu, A., de Mattia, A., Krolewski, A., Rashkovetskyi, M., Ross, A. J., To, C., Aguilar, J., Ahlen, S., Anand, A., BenZvi, S., Bianchi, D., Brooks, D., Castander, F. J., Claybaugh, T., Macorra, A. d. l., Costa, J. D., Doel, P., Ferraro, S., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gutierrez, G., Herrera-Alcantar, H. K., Howlett, C., Huterer, D., Ishak, M., Joyce, R., Kirkby, D., Kisner, T., Kremin, A., Lahav, O., Lamman, C., Landriau, M., Guillou, L. L., Manera, M., Martini, P., Meisner, A., Miquel, R., Moustakas, J., Nadathur, S., Niz, G., Palanque-Delabrouille, N., Percival, W. J., Prada, F., Pérez-Ràfols, I., Rossi, G., Samushia, L.

2 Apr 2026, In: Journal of Cosmology and Astroparticle Physics. 2026, 04, 32p., 004

Research output: Article

Validation of the DESI-DR1 3x2-pt analysis: scale cut and shear ratio tests

Emas, N., Porredon, A., Blake, C., DeRose, J., Aguilar, J., Ahlen, S., Bianchi, D., Brooks, D., Castander, F. J., Claybaugh, T., Cuceu, A., Macorra, A. d. l., Dey, A., Dey, B., Doel, P., Ferraro, S., Forero-Romero, J. E., Garcia-Quintero, C., Gaztañaga, E., Gontcho, S. G. A., Gutierrez, G., Heydenreich, S., Honscheid, K., Huterer, D., Ishak, M., Joudaki, S., Joyce, R., Jullo, E., Juneau, S., Kehoe, R., Kirkby, D., Kisner, T., Kremin, A., Krolewski, A., Lahav, O., Landriau, M., Lange, J. U., Guillou, L. L., Leauthaud, A., Manera, M., Miquel, R., Nadathur, S., Percival, W. J., Prada, F., Rossi, G., Ruggeri, R., Sanchez, E., Saulder, C., Semenaite, A., Seo, H.

31 Mar 2026, In: Open Journal of Astrophysics. 9, 21p.

Research output: Article

Euclid preparation LXXXVII. Non-Gaussianity of 2-point statistics likelihood: Precise analysis of the matter power spectrum distribution

Collaboration, E., Bel, J., Beauchamps, S. G., Baratta, P., Blot, L., Carbone, C., Corasaniti, P. -., Sefusatti, E., Escoffier, S., Amara, A., Andreon, S., Auricchio, N., Baccigalupi, C., Baldi, M., Bardelli, S., Battaglia, P., Biviano, A., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Cañas-Herrera, G., Capobianco, V., Cardone, V. F., Carretero, J., Casas, S., Castellano, M., Castignani, G., Cavuoti, S., Chambers, K. C., Cimatti, A., Colodro-Conde, C., Congedo, G., Conselice, C. J., Conversi, L., Copin, Y., Costille, A., Courbin, F., Courtois, H. M., Silva, A. D., Degaudenzi, H., Torre, S. d. l., Lucia, G. D., Markovic, K., Percival, W. J., Gaztanaga, E., Nadathur, S., Naidoo, K.

30 Mar 2026, In: Astronomy and Astrophysics. 708, 19p., A105

Research output: Article

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Dr Seshadri Nadathur

Summary

Research interests

Research outputs

2026