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U of T astrophysicist wins Humboldt Research Award

Harald Pfeiffer: “Black holes are my passion”

“It’s very cool to have run computer calculations and to find, a few years later, that the thing you have computed turns out to be real,” Harald Pfeiffer says (photo by Diana Tyszko)

Black holes have allowed Associate Professor Harald Pfeiffer’s career to shine as brightly as the most vivid star in the night sky.

An expert in binary black holes, Pfeiffer – of the University of Toronto’s Canadian Institute for Theoretical Astrophysics and Faculty of Arts & Science – learned weeks ago that he had received one of about 20 Humboldt Research Awards given out worldwide in 2015.

But news of the Humboldt honour came just before an international group of scientists, including Pfeiffer, announced an incredible research breakthrough: the discovery of gravitational waves. (Read the CBC coverage.) In a stellar year for the U of T astrophysicist, celebrating the Humboldt just had to wait.

Read more about the LIGO discovery

The Humboldt Research Award is granted by the Alexander von Humboldt Foundation in Germany “in recognition of a researcher's entire achievements to date to academics whose fundamental discoveries, new theories, or insights have had a significant impact on their own discipline and who are expected to continue producing cutting-edge achievements in the future.” The prize gives the awardee an opportunity to work at a research institution in Germany for up to a year, collaborating with colleagues there on a long-term research project.

Pfeiffer, who was born in Germany, was already on sabbatical there at the Max Planck Institute for Gravitational Physics when he learned of the award.

“It is very important recognition and I am very happy to have received it,” he said during a phone interview from Potsdam, Germany.

The award, valued at 45,000 Euros (C$65,000), will defray some of the costs of Pfeiffer’s sabbatical year and assist with his research, which in turn, will further the scientific understanding of black holes.

“Black holes are my passion,” Pfeiffer said. “I have spent my entire research career exploring binary black holes.”

For the past three years, Pfeiffer has been a part of LIGO, the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, a project designed to detect gravitational waves. In February 2016, LIGO scientists announced the first observation in history of a gravitational wave, using sensitive scientific instruments to record this ripple in the fabric of spacetime. It is a phenomenon anticipated by Albert Einstein’s Theory of Relativity more than a century ago and it not only confirmed the existence of gravitational waves; it was also the first detection of a binary black hole.

Pfeiffer’s expertise was instrumental to the discovery. His research has focused on computing the wave forms that would result from all possible collisions of black holes, i.e., collisions between black holes of various masses. When the collision was detected, the LIGO team was prepared.

“Modelling is important because you need to know the potential shape of the wave,” Pfeiffer said.”It’s easier to find a gravitational wave when you know what you’re looking for. Once the candidate is identified, modelling helps you to find out what you’ve actually seen.

“The precise system being observed is exactly what I’ve been working on all along,” he added. “In that sense, my calculations were instrumental in determining what black holes had been seen.

“It’s very cool to have run computer calculations and to find, a few years later, that the thing you have computed turns out to be real.”

Now that the first binary black hole has been detected, Pfeiffer says a next step is to identify as many as possible and establish their masses and spins. Determining the way they spin will provide clues about how the black holes were formed and offer more insights into our universe.

He has already begun collaborating with the research group at the Max Planck Institute for Gravitational Physics and says it is a very natural extension of the work he has done in the past.

“I want to contribute to any new detection,” Pfeiffer said. “The last few months have been stunningly great.”