Postcard from California: Maks Koncilja from UC Berkeley

Maks Koncilja, a master’s student of physics and financial mathematics at FMF UL, completed a research visit to UC Berkeley in the United States as part of the ASEF program. He worked under the mentorship of cosmologist Prof. Dr. Uroš Seljak on the research topic of gradient-based persistent sampling.

The research area Maks focused on seeks ways to generate samples from a given probability distribution in a high-dimensional space as efficiently as possible. Such problems frequently arise in physics, statistics, cosmology, and machine learning, where we aim to infer a large number of unknown quantities from data. As part of his research, Maks evaluated the quality and efficiency of a new method developed in Seljak’s group compared to well-established numerical sampling methods, particularly on challenging high-dimensional cases.

During his research visit, he attended invited lectures, seminars, and panel discussions, including topics beyond cosmology. Throughout the semester, the campus was exceptionally lively and filled with diverse events: from guided birdwatching, dance workshops, and ecological performances to literary evenings and poetry readings. Although the fellow could not attend them all, he was impressed by the variety of extracurricular life and student-organized activities. As key characteristics of Berkeley, he highlights the fast research pace, constant establishment of new collaborations, mutual support, and dedication to work.

During his stay, Maks was hosted by Tony Hansen, a retired experimental physicist, inventor, and successful businessman. Once a month, Tony organizes pizza nights for students and researchers, attended by undergraduate and doctoral students as well as postdoctoral researchers alike. In a simple and relaxed way, he creates a space for connecting young people from various research fields. At the April gathering, Maks met a group of doctoral students in inorganic chemistry led by Rhett Bryant, who organized weekend hiking trips into the surrounding hills.

An important part of the experience was also the support of former ASEF fellow and Seljak’s doctoral student Jakob Robnik. Jakob traditionally lends his bicycle to incoming ASEF students at Berkeley, and he also helped Maks with practical advice, feedback on research results, and pleasant conversations over lunch. A special moment of the visit was Jakob’s formal doctoral graduation ceremony.

By a happy coincidence, Prof. Dr. Uroš Seljak celebrated his 60th birthday during Maks’s visit. In his honor, a three-day conference was organized in the tallest skyscraper in San Francisco. Maks had the opportunity to attend the reception, where the host himself prepared several culinary specialties characteristic of the Primorska (Goriška) region. The event was attended by numerous cosmologists with whom Professor Seljak has collaborated throughout his productive scientific career.

As part of a Christian community, the fellow also visited Yosemite National Park over a weekend alongside other researchers in the natural sciences from Berkeley. Together, they hiked the scenic Upper Yosemite Fall Trail.

In the final weeks of his research visit, Maks visited former ASEF fellow Gregor Žunič, co-founder of the company Browser Use, based along the waterfront in San Francisco. There, he gained insight into the workings of Silicon Valley startups and experienced a different, entrepreneurial side of California’s tech ecosystem.

After concluding his research stay, Maks and his partner Katarina embarked on a ten-day road trip across California. Their route took them through Yosemite, Mono Lake, the ghost town of Bodie, the Mammoth Lakes area, and Alabama Hills. They spent four days hiking the famous High Sierra Trail before driving along Highway 1 past Big Sur. Along the way, they spotted diverse wildlife, including marmots, deer, a wildcat, a bear, and several endangered bird species.

Even after returning to Slovenia, Maks remains connected with Prof. Dr. Seljak’s research group. He continues to attend meetings where they discuss results and suggest improvements for the research project.

Berkeley provided Maks not only with research experience but also with valuable insight into California’s vibrant academic environment. He was particularly impressed by the playful curiosity and kindness of the cosmology researchers. The fellow sincerely thanks Dr. Jakob Robnik for all his help and his mentor Prof. Dr. Uroš Seljak for an exceptional research opportunity. Among his most unforgettable memories will remain the moments spent with host Tony Hansen, whose breadth of vision, cheerfulness, and generosity quickly make him an inspiration to anyone who gets the chance to meet him.