Cosmoparticle Initiative


Hiranya Peiris

Professor of Astrophysics

Department of Physics and Astronomy

University College London

I am a cosmologist working in both theory and observation. I study the fossilized heat of the Big Bang, the cosmic microwave background (CMB), to understand the physics that governed the very early universe. I use large surveys of galaxies to study the subsequent evolution of the universe, with a particular focus on measurements that constrain fundamental physics. I also work at the interface between cosmology and theoretical physics, to refine physical models that explain cosmological observations. The emerging field of astrostatistics, and the development of optimal numerical algorithms capable of handling very large datasets, are common threads that run through much of my work.

I also enjoy thinking about galaxy evolution, stellar dynamics, and the structure of the Milky Way.

You can read more about my research in the group blog.


I am a Professor of Astrophysics in the Astrophysics Group in the Dept. of Physics and Astronomy at UCL and the Director of the UCL Cosmoparticle Initiative which brings together researchers in the Astrophysics and High Energy Physics Groups with space scientists from the Mullard Space Science Laboratory. I am currently spending half my time away from UCL as Director of the Oskar Klein Centre for Cosmoparticle Physics in Stockholm. I am also the Principal Investigator of the CosmicDawn project, funded by the European Research Council under the FP7 Ideas programme.

Prior to beginning a faculty position at UCL in 2009, I was an STFC Advanced Fellow at the Institute of Astronomy, University of Cambridge and a Junior Research Fellow at King's College Cambridge. Previously, I was a Hubble Fellow in the Kavli Institute for Cosmological Physics at the University of Chicago. I did my postgraduate research at the Department of Astrophysical Sciences at Princeton University. I was an undergraduate at the University of Cambridge, where I was a member of New Hall. I was born in Sri Lanka, a beautiful island in the Indian Ocean.

From 2001-2006 I was a member of the WMAP Collaboration. The CMB data from the Wilkinson Microwave Anisotropy Probe (WMAP) formed the foundation for the era of precision cosmology, and dramatically improved our understanding of the basic characteristics of the Universe (its contents, history, expansion rate and eventual fate).

I am currently a member of the Planck Collaboration. Planck, an ESA satellite, is the successor to WMAP and has mapped the primordial fluctuations with exquisite precision. I am also a member of the ongoing Dark Energy Survey (DES), the Dark Energy Spectroscopic Instrument (DESI, starting in 2018), and the Large Synoptic Survey Telescope (LSST, currently under construction), next generation galaxy surveys that will yield deep insights into the evolution of the Universe and its underlying physics.

I serve on the Editorial Board of Physics Letters B, a journal which ensures rapid publication of important new results in particle physics, nuclear physics and cosmology.

I served as Vice-President (Astronomy) of the Royal Astronomical Society during 2016-2018.

I am supported by

ERC logo…

Portrait of Hiranya Peiris by Max Alexander