'I was headed to med school — until a friend who loved math changed everything'

In 2003, a 14-year-old boy was accepted to the Korea Science Academy, the country's first school for gifted students, completing middle school ahead of schedule. He then graduated from that institution — already a gathering place for the nation's top science and engineering talent — six months early, and began university life at KAIST at 17.

He finished the KAIST undergraduate program in just two years and set foot in the United States at 19 as a Samsung scholarship recipient. After earning his doctorate in mathematics from Princeton University, he was appointed to the faculty of UC Berkeley's mathematics department in 2019 at the age of 31 — an institution that has produced more than 100 Nobel laureates. Oh Sung-jin carried the label of "youngest" through every stage of his education from middle school through university. He stepped back into the spotlight this year when he was named the physics and mathematics recipient of the 36th Ho-Am Prize in Science.

Oh returned to South Korea on May 29 for the school break and, with barely a moment to breathe after the Ho-Am Prize ceremony, was already deep in preparations for two upcoming events: an international conference marking the 80th anniversary of the Korean Mathematical Society later this month, and his invited lecture at the 2026 International Congress of Mathematicians in Pennsylvania in July.

Oh had little love for mathematics as a student, instead throwing himself into biology, and his original dream was to follow his father into medicine. That changed in his second year at the Korea Science Academy, when he met a friend who was passionate about math.

"In high school, my friend and I would stay up all night talking about mathematics," Oh said with a laugh. "I had been planning to go to medical school, but his influence turned me into a mathematician. He, in turn, was influenced by me and became a doctor. Even now, when we talk, we tell each other that we found our calling thanks to the other person."

Oh made up his mind to pursue mathematics seriously during his time in the Department of Mathematical Sciences at KAIST, and his father respected that decision. "My parents didn't oppose it, but I think they quietly supported me while worrying in the background," he said. "They don't worry anymore. With this award, they've been receiving a lot of congratulations from the people around them."

His wife, Park Ji-hyun — a fellow Korea Science Academy alumna who holds a bachelor's degree in physics from KAIST and a doctorate in physics from Princeton — said she still remembers the curiosity that defined her husband as a student. "He was full of curiosity back then," she said. "He's still exactly the same."

The Ho-Am Prize, established in 1990 in honor of Samsung founder Lee Byung-chul, selects winners each year in six categories — the Science Prize (physics and mathematics; chemistry and life sciences), the Engineering Prize, the Medicine Prize, the Arts Prize and the Community Service Prize — and presents each recipient with a medal and 300 million won (about $197,000).

The Ho-Am Foundation assembled a 46-member judging committee of domestic and international experts beginning last December and conducted three rounds of evaluation, followed by an assessment by an advisory board composed of overseas scholars including Nobel laureates. The winner was selected after four months of deliberation.

"I am deeply moved to be recognized by respected colleagues and scholars I look up to," Oh said. He added that he was particularly grateful that the Science Prize has been divided into separate physics-and-mathematics and chemistry-and-life-sciences categories since 2020. "I got the impression that they believe in the importance of foundational disciplines like mathematics and physics," he said.

Oh's connection with Samsung dates to 2008, when he entered graduate school at Princeton on a Samsung scholarship and completed his doctoral dissertation while focusing on his research. In 2017, his research project was selected for support under Samsung's Future Technology Incubation Program, allowing him to pursue deeper inquiry. "It was research that required a very long runway," he said. "Because I had five years of funding, I didn't have to worry about research costs. My recent results also trace back to that support."

After years of calculating how waves behave inside and outside black holes, Oh discovered that waves fading outside a black hole amplify explosively the moment they cross inside — and used that finding to provide the first mathematical proof that a passage to another universe is highly unlikely to exist.

The global academic community took notice of Oh's achievement in using nonlinear hyperbolic partial differential equations to characterize the instability of black hole interiors — work seen as a breakthrough in resolving one of modern mathematics' hardest open problems — and invited him to deliver a lecture at the 2026 International Congress of Mathematicians.

The congress, held every four years, is sometimes called the "Mathematics Olympics." Princeton professor Huh June-hee won the Ho-Am Prize in Science (physics and mathematics) in 2021 and went on to become the first Korean to receive the Fields Medal — mathematics' equivalent of the Nobel Prize — at the following congress in 2022. Oh is now widely regarded as a future Fields Medal candidate.

Asked how students might find a way into mathematics at a time when so many give up on the subject entirely, Oh offered a surprising answer: "It matters who is around you."

"In high school, talking with friends who found math enjoyable amplified that enjoyment for me," he said. "Without those experiences, I don't think I would have fallen this deeply in love with it."

Asked how he hopes to be remembered as a mathematician, he said: "I want to be remembered as someone whose work made problems that once seemed impossibly hard look genuinely easy."