# “Society benefits from diversity,” says Perimeter’s 2024 BMO Inclusive Excellence Fellow Susanne Schander

Women are underrepresented in physics.

According to *Canadian Physics Counts: An Exploration of the Diverse Identities of Physics Students and Professionals in Canada*, about 21.7 percent of doctoral degrees in physics in 2022 went to women.

But Susanne Schander, the 2024 BMO Inclusive Excellence Postdoctoral Fellow, is hoping that for the next generation of young women, that will have changed.

“I really hope that in the future, they will have an easier start, and that it won't be as hard for women to find their place in the more male-dominated fields like physics or mathematics.”

Schander says she has been privileged to be at Perimeter as a postdoctoral fellow in cosmology and quantum gravity since 2020.

But she recognizes that there are still barriers for women in physics at many institutions.

Women and others in underrepresented groups are typically the ones who spend considerable effort on improving working conditions and career opportunities for others, something that takes time. But at many institutions, that work is not part of the academic evaluations.

Schander says that is why the BMO fellowship makes such a great contribution to the Equity, Diversity, and Inclusion (EDI) efforts at Perimeter.

“It compensates for EDI advocacy, which will help encourage more researchers to get involved,” Schander says.

Helen Seibel, Head of Community and Employee Giving at BMO, says her financial institution sees an inclusive society as a key driver of progress.

“BMO is proud of its partnership with Perimeter Institute and our shared commitment to fostering environments where everyone can thrive,” Seibel said. “It truly reflects how we live our Purpose, to Boldly Grow the Good in business and life.”

Schander hopes that as the BMO Inclusive Excellence fellow, she can help to make sure women researchers do not face barriers in physics careers.

Schander is originally from Germany. Prior to becoming a postdoc at Perimeter, she did a double PhD at Friedrich-Alexander-Universität (FAU) in Erlangen-Nürnberg, Germany and Université Grenoble Alpes in France. Her PhD focused on the intriguing area of quantum cosmology, and she has delved deeper into it since arriving at Perimeter.

“I have continued working on quantum cosmology, but I would say my focus now is more on foundational and mathematical questions and quantum gravity,” she says.

Many physicists at Perimeter are trying to find a solution to the quantum gravity problem. They want to find a way to make the force of gravity, as described by Albert Einstein’s general relativity theory, fit into our understanding of quantum theory.

This is the holy grail of physics. A unified theory that meshes the large cosmological picture with the theory of the smallest particles and forces would open a whole new window into the understanding of how nature works.

But it is not easy to find, and there are various approaches to quantum gravity.

There is string theory, which posits that everything is made up of tiny strings. String theory gives rise to the concept of the holographic duality, whereby a lower dimensional particle theory can be connected to a higher dimensional space that includes gravity.

Another possible approach is to “quantize” spacetime. That is, just take spacetime and break it down into its most fundamental units.

Loop quantum gravity, where the smooth background of Einstein's theory of gravity is replaced by nodes and links so that space is built up of discrete chunks, is one approach to quantizing spacetime.

But all the approaches to quantizing spacetime have some limitations and problems. Einstein’s general relativity describes gravity in terms of the smooth curvature of spacetime. But that does not mesh with quantum theory in which particles and forces are discrete, interacting packets of wavefunctions. The two theories speak different languages.

Schander has worked on loop quantum gravity in the past. But recently, she has introduced a new approach to quantum gravity that revisits an older idea, quantum geometrodynamics, which originated with famous physicist John Wheeler (who popularized the idea of black holes) in the 1960s.

Geometrodynamics is synonymous with general relativity but is more specifically linked to a formulation of general relativity in which geometry evolves over “time” (in contrast to Einstein’s original formulation). This idea was first introduced by physicists Richard Arnowitt, Stanley Deser and Charles Misner in 1959. In the 1960s, Wheeler along with Bryce DeWitt attempted to develop a quantum version of geometrodynamics but their efforts were thwarted by seemingly unsurmountable mathematical challenges.

Schander says in Wheeler’s day, the mathematical tools needed to make progress with this approach did not exist.

“But now, we can use new mathematical tools to redefine this approach. We are using tools from lattice quantum field theory, which is a very well-established field now” she says.

While continuing this fascinating exploration of the lattice version of quantum geometrodynamics, Schander is also very much committed to the Perimeter Institute’s Women in Physics working group, with the goal of enhancing women empowerment and inclusivity in the workplace. The group organizes numerous events each year to better connect women and provide them with career advice.

The group has also started an EDI Journal Club.

“It focuses on EDI topics. We bring everyone to the table to discuss the latest EDI research and current topics, to generate new ideas and possibly implement them,” she said.

There have so far been eight journal club meetings and they have all resulted in lively discussions, Schander added.

Schander said making physics more diverse and inclusive field is something that everyone will benefit from.

“Society supports research financially, and gains from the research that happens. But research benefits from having more ideas from different people,” she said. “Making the research better and more diverse makes society a better place.”

**BMO established the Inclusive Excellence Postdoctoral Fellow in 2022 with a $400,000 gift to Perimeter. **

### About PI

Perimeter Institute is the world’s largest research hub devoted to theoretical physics. The independent Institute was founded in 1999 to foster breakthroughs in the fundamental understanding of our universe, from the smallest particles to the entire cosmos. Research at Perimeter is motivated by the understanding that fundamental science advances human knowledge and catalyzes innovation, and that today’s theoretical physics is tomorrow’s technology. Located in the Region of Waterloo, the not-for-profit Institute is a unique public-private endeavour, including the Governments of Ontario and Canada, that enables cutting-edge research, trains the next generation of scientific pioneers, and shares the power of physics through award-winning educational outreach and public engagement.