Professor Kazuya Koyama
Biography
I am a Professor of Cosmology in the Institute of Cosmology and Gravitation at the University of Portsmouth. My research interests lie in theoretical cosmology, particularly the origin of structure in our Universe and the late time acceleration of the Universe. My research is supported by the Science and Technology Facilities Council and the European Research Council’s consolidator grant “Cosmological Tests of Gravity”. I was supported by the European Research Council’s starting grant, “Modified gravity models as an alternative to dark energy” between 2008 and 2013. I was awarded my PhD from Kyoto University in 2002. Previous awards include RCUK academic fellowship, PPARC psotdoctoral fellowship, Japanese JSPS potdoctoral fellowship. In 2009 I was awarded the Philipe Leverhulme prize and in 2010 I received the Young Scientist Award of the Physical Society of Japan. I was a PI of a Royal Society International Joint Project with the Yukawa Institute at Kyoto University. The collaboration between Portsmouth and Kyoto University was awarded the Daiwa-Adrian prize in 2010.
Research interests
My main research interest lies in theoretical cosmology. I study the origin of structure in our Universe and test the early universe models using the statistical properties of the cosmic microwave background and the large scale structure of the Universe. I am also interested in explaining the late time acceleration of the Universe. Particularly I investigate a possibility to realise the late time acceleration by modifying general relativity on cosmological scales and develop cosmological tests of gravity.
Research outputs
2024
Efficient compression of redshift-space distortion data for late-time modified gravity models
Gómez-Valent, A., Koyama, K., Toda, Y.
11 Nov 2024, In: Journal of Cosmology and Astroparticle Physics
Modelling the covariance matrix for the power spectra before and after the BAO reconstruction
Koyama, K., Wang, Y., Zhao, G., Zhao, R.
24 Oct 2024, In: Research in Astronomy and Astrophysics
Theory of interacting vector dark energy and fluid
Koyama, K., Pookkillath, M. C.
15 Oct 2024, In: Journal of Cosmology and Astroparticle Physics
Extending MGCAMB tests of gravity to nonlinear scales
Bose, B., Koyama, K., Pogosian, L., Saadeh, D., Wang, Z., Yi, L., Zhao, G.
15 Oct 2024, In: Journal of Cosmology and Astroparticle Physics
Testing screened modified gravity with SDSS-IV-MaNGA
Desmond, H., Koyama, K., Landim, R. G., Penny, S.
1 Oct 2024, In: Monthly Notices of the Royal Astronomical Society. 534, 1, p. 349–360
Euclid preparation. XLIV. Modelling spectroscopic clustering on mildly nonlinear scales in beyond-ΛCDM models
Aghanim, N., Amara, A., Andreon, S., Auricchio, N., Baldi, M., Bardelli, S., Bella, L. F. d. l., Bodendorf, C., Bonino, D., Bose, B., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., Capobianco, V.,
24 Sep 2024, In: Astronomy and Astrophysics. 689, 29p., A275
Euclid. I. Overview of the Euclid mission
Achúcarro, A., Adam, R., Adamek, J., Addison, G. E., Aghanim, N., Aguena, M., Ajani, V., Akrami, Y., Al-Bahlawan, A., Alavi, A., Albuquerque, I. S., Alestas, G., Alguero, G., Allaoui, A., Allevato, V.,
29 Aug 2024, In: Astronomy and Astrophysics
Modeling nonlinear scales with COLA: preparing for LSST-Y1
Aguiar, B. F. d., Brando, G., Falciano, F., Gordon, J., Koyama, K., Miranda, V., Rebouças, J., Winther, H. A.
21 Aug 2024, In: Monthly Notices of the Royal Astronomical Society
A multitracer analysis for the eBOSS galaxy sample based on the effective field theory of large-scale structure
Bacon, D., Crittenden, R. G., Donald-McCann, J., Feng, Y., Gsponer, R., Koyama, K., Mu, X., Wang, Y., Zhang, W., Zhao, G., Zhao, R.
2 Jul 2024, In: Monthly Notices of the Royal Astronomical Society. 532, 1, p. 783–804
The separate-universe approach and sudden transitions during inflation
Assadullahi, H., Gow, A. D., Jackson, J. H. P., Koyama, K., Vennin, V., Wands, D.
9 May 2024, In: Journal of Cosmology and Astroparticle Physics. 2024, 5, 35p., 053