When Andreas Albrecht was a grad student at the University of Pennsylvania, he was looking for an advisor in particle physics. When he asked a new faculty member to become his advisor, the researcher said he was now focusing on cosmology — a field in which Albrecht said he wasn’t all that interested.

“I swallowed my disappointment and said, ‘I’d love to do cosmology with you,’ and I'm still doing that many years later,” said Albrecht, now a distinguished professor emeritus in the UC Davis Department of Physics and Astronomy. 

As it turned out, his openness would soon bear fruit: A short time later, the pair proposed an idea that changed the way scientists think about the beginning of the universe.

A new field, a new discovery

Cosmologists theorize that in the very earliest history of the universe, space itself expanded at an extraordinary rate during a period called inflation, stretching the universe smooth and explaining why matter and energy are so evenly distributed today. When this idea was first proposed in the early 1980s, the original model had a critical flaw: it couldn't explain how inflation ended in a way that left a uniform universe. Albrecht and his advisor, Paul Steinhardt, proposed a solution in 1982: “slow roll” inflation, where the expansion — while still happening in a tiny fraction of a second — would come to a more gradual and gentler end, leaving the universe as it is now.

Albrecht said he quickly found cosmology to be a field with unanswered questions that led to major changes over the course of his career.

“There are a lot of big questions that are a lot of fun to think about,” he said, noting his ongoing skepticism, even about whether his own “slow roll” inflation explains why the universe began in such a precisely balanced state.

“The sort of ‘party line’ is that we’ve solved these very deep questions,” he said. “There’s no doubt that inflation has been validated as a powerful tool for analyzing cosmic data and connecting it to ideas about fundamental physics. But if you think carefully about the deepest questions — the precisely balanced state of the universe —I feel many claims about inflation’s accomplishments are overstated.”

That willingness to question convention has stuck with Albrecht throughout the course of his career.

Before joining UC Davis in 1998, his career included stops at the Fermi National Accelerator Laboratory and Imperial College London, as well as numerous accolades including election to the American Academy of Arts and Sciences in 2016.

He was the first cosmologist hired at UC Davis; he and Professor Bob Becker, an astronomer, were tasked with building the cosmology program at the university. Their first hire was Professor Lloyd Knox, with whom Albrecht later served on the Dark Energy Task Force, a project funded jointly by NASA, the Department of Energy and the National Science Foundation. At the time, research into dark energy was a “wild west” of researchers debating which experiments would uncover more information about the force thought to be behind the acceleration of the expansion of the universe. The group’s 2006 report laid out recommendations for future experiments that could shed more light on dark energy.

“We created some important insights into how to best approach it and recommended certain kinds of telescopes, all of which either have now been built or are about to be,” he said, citing the Simonyi Survey Telescope at the Vera C. Rubin Observatory, which has another UC Davis connection: Its chief scientist is Distinguished Research Professor Tony Tyson, who was recently named to Time’s annual list of the 100 most influential people in the world.

Albrecht added that the basics of dark energy continue to “stump” many researchers: “It’s provocative in an exciting way — so there’s no end of big developments in the recent decades. It’s been really exciting.”

Albrecht was also the inaugural director of a center bringing together UC Davis physicists and mathematicians on a common goal: the Center for Quantum Mathematics and Physics, or QMAP.

Albrecht has seen his field evolve: He said when he was a student, “people would make jokes about cosmologists not knowing any numbers within a factor of 10 or 100 — now it’s a real precision subject.”

Thinking back about other major changes, he recalled a phone call about the first signal detected by NASA’s Cosmic Microwave Background Explorer satellite, or COBE, which provided a picture of the radiation left over after the Big Bang; and a University of Cambridge conference where a colleague gave him a sneak peek at results that would disprove a popular theory about the origins of the universe (Albrecht had to leave the conference to teach a class before the formal announcement was scheduled to be made). 

“If I were to look at the span of the history of science and get to choose which topic and which time to be doing it, I couldn't do better than what I've landed with doing cosmology in this era,” he said. “It’s absolutely amazing.”

A varied environment 

Albrecht grew up dreaming of becoming a professional violinist, practicing hours a day; he said his high school physics class “totally turned me around” and led him to a career in science. Now, he said it has been very satisfying to be among such a varied group of experts and to also teach students without a background in science.

“These questions about the cosmos are so exciting,” he said. “Teaching this kind of topic gave me an opportunity to help students who are not science majors understand a little bit of what science is, how science works. And that’s an important part of their education to go out in a world where a lot depends on science these days.”

That varied environment has been a benefit of being at UC Davis.

“I really love being at UC Davis to be among historians and artists and musicians,” he said. “That has been really important.”

Science also drew Albrecht in because it felt more stable amid the political protests he witnessed as a child in the 1960s and ’70s, but it later led to even more questions, he said.

“There was a lot of fraught political passions flying around and the sense of grounding in some solid topics to think about was very attractive at the time,” he said. “And I think it's interesting because in the end, what excites me are the unknowns, the parts that are not solid. But in physics, we try to make them so.”