John Antoniadis is a Dunlap Fellow at the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto. Ηe was part of the team that discovered the most massive neutron star to date and has helped set some of the most stringent limits on deviations from General Relativity published by Albert Einstein, in the strong-field regime.

He was born in Didymoteicho, Greece, in 1986 and studied Physics at the Aristotle University of Thessaloniki. He received his PhD from the Max Planck Institute for Radio Astronomy in Bonn. He started at the Dunlap Institute in October 2014.

His research focuses on using pulsars as laboratories to study fundamental physics. He is particularly interested in measuring the masses of millisecond pulsars and inferring the equation-of-state of dense nuclear matter. He also studies the impact of gravitational-wave emission on the orbits of binary pulsars. He is also interested in binary evolution and uses observations of selected objects and theoretical simulations to study the formation of binary neutron stars.

At the Dunlap, Antoniadis is working on pulsar scintellometry, a new observing method that seeks to use the interstellar medium as a giant telescope that will help us measure the properties of pulsars with extreme precision. In 2016, he was awarded a prestigious John C. Polanyi Prize in Physics for his research into neutron stars and other compact astronomical objects.

Other awards and prizes he has received include the Otto Hahn Medal of the Max-Planck Society (2014), the Best PhD in Gravitational, Nuclear and Atomic physics from the German Physics Society (2013) and the Best PhD, University of Bonn (2013).