Ulrik Bo Rufus Enstad
Fulbright Visiting Student Researcher 2018-19
I spent six months of my PhD studies in mathematics, from August 2018 to February 2019, in Boulder CO on a research stay funded by the Fulbright program. Boulder is a city with a population just below 100,000. Just 43 km from Boulder lies Denver, the biggest city in Colorado. Boulder is located right where the great plains end and the Rocky mountains begin. There are numerous trail heads in the area, with the famous Flatirons being a popular destination, and some of the most famous ski resorts in the US are only 1-2 hours away by car.

My host university was the University of Colorado in Boulder (CU). The university is highly ranked, has over 30,000 students and was founded in 1876. As with many US universities, sports is big at CU, and they have their own football stadium, Folsom Field, which is the home field of the Colorado Buffaloes. In addition, they have newly renovated recreational facilities that sport an indoor ice skating rink and two swimming pools.
The Department of Mathematics at CU is medium-sized, with 25 faculty and over 50 graduate students. The research areas include algebraic and differential geometry, logic and foundations, and operator algebras, which is my field. The operator algebra group currently has four faculty, two emeriti and two graduate students. The professor that was my host for the stay wrote or co-wrote the papers that constitute the main background material for my PhD project, so there is no doubt it was very relevant professionally for me to visit her.
During my stay, we had many interesting discussions, both related to my main PhD project and other topics. We made significant progress towards generalizing a proposition from one of these papers, but there are still some obstacles to handle before getting to the solution. I actually made most progress on one of my side projects, and I credit this both to the discussions with my host professor but also to the change of location itself, which I found to be incredibly inspiring. I befriended several graduate students at the department, including the ones in operator algebras. There was also a PhD student from Australia visiting the department for the first three months of my stay who I already met at a conference prior to my US stay. It was very helpful to know someone else who was also new in Boulder, and we could get help from each other to handle issues such as getting a US cell phone plan, getting a bike, etc. I hope to stay in touch with all of these students and hopefully see them at conferences in the future.
I ended up renting an apartment from a landlord with Norwegian ancestry. He and his family lived next door, and I was regularly invited for dinner. They have been in Norway before and plan to come here in the future, and I will stay in touch with them.
I also traveled a lot during my stay in the US, and visited a total of six different states. I went to a couple of conferences in San Francisco and Seattle. I also went on a roadtrip with my girlfriend throughout Colorado and Utah, which was amazing. The nature is really beautiful and incredibly diverse in these two states, and we saw everything from sand dunes to deep canyons and strange rock formations such as arches.

During this roadtrip, we stayed at AirBnBs throughout Colorado, often inside people’s homes. It was very nice to meet people from other places in Colorado and not just in Boulder, which is considered a bit of a bubble. Overall, I had a really great research stay in Boulder. I made tremendous progress on my research, expanded my professional network, went to a couple of conferences where I met possible future collaborators, and presented my work in two seminars. I also made several friends, both in academics and outside, whom I plan to stay in contact with. I was lucky to travel a lot, both in Colorado but also to the west and east coast, and I really got to see just how diverse the US is (it’s hard to believe that Seattle and Miami are in the same country). Lastly, I would definitely say my English has improved. I am really grateful that I received the Fulbright scholarship, since a US stay of this duration would not have been possible without it. Being back in Oslo, I really look forward to continuing my everyday life and research, having learned a lot from living in the US. And of course, I hope to visit the US and Boulder sometime in the future.