Thomas Hertog is a Belgian cosmologist at KU Leuven university and a key collaborator of Professor Stephen Hawking. He received his master’s degree in physics from the KU Leuven and his doctorate from the University of Cambridge. He joined the University of California as a research fellow in 2002 and became fellow at CERN, Geneva, in 2005. In 2011 he returned to Belgium where he is currently professor at the Institute for Theoretical Physics of the KU Leuven. Hertog is also guest professor at the Kavli Institute for Theoretical Physics, Santa Barbara, visiting senior fellow at Trinity College, Cambridge, and affiliate member of the International Solvay Institutes for Physics, Brussels.

At the KU Leuven Hertog leads a research team that investigates the physical nature of black holes and the big bang. In this context he has a longstanding interest in gravitational waves — ripples of spacetime once predicted by Einstein. Hertog leads Belgium’s participation in the European Space Agency’s first gravitational-wave mission and in Einstein Telescope, a future gravitational-wave observatory underground that may well be a game changer for Belgium.

He has recently wrote the book "On the Origin of Time" about his theory of the origin of the universe and his journey with Stephen Hawking.