Daniel Phillips, Professor at the Department of Physics and Astronomy at Ohio University, USA, is the holder of the 2024 Tage Erlander visiting professorship as instituted by the Swedish Research Council. His guest professorship is hosted by the Division of Subatomic, High Energy and Plasma Physics at the Department of Physics at Chalmers.
How would you describe your research?
"I am interested in models of the nucleus and models of nuclear reactions, and I'm particularly interested in building descriptions where we can estimate the model uncertainty of the description. For those of us doing theoretical research, when you're comparing experimental data, that data often comes with uncertainties. But theoretical predictions come with no uncertainties, which is not helpful, because it suggests that if you took that at face value, you would think that the theorists were absolutely certain that this was the number. Whereas in fact, all it means is that they haven't really bothered to estimate what the real uncertainty is."
"In my field of nuclear physics there have been a couple of tools that have been developed and employed over the last 25 years to attack this problem. You organise the problem so that the most important mechanisms are included first and the precision of the calculation gets better as you do more and more work. Then you combine that organisation with sophisticated approaches to treating data to quantify the impact of things you haven't calculated yet."
Why did you become interested in this field of research?
"When I started working on theoretical nuclear physics, I was frustrated that sometimes theoretical nuclear physicist A would do a calculation and predict the number and theoretical physicist B would do a different calculation and predict different number. And then they would both sort of shrug and be okay with that. But the thing that attracted me to the approach of uncertainty quantification was that it for provided for such situations in a reliable way – I know where my model fails, but I also know where it is true."
What are your expectations of the Tage Erlander guest professorship, and what will your cooperation with the Department of Physics be like?
"In the proposal to the Swedish Research Council that Professor Christian Forssén at the Department of Physics and I wrote, we discussed some nuclear processes that, if you measure them precisely enough, you could detect the presence of physics beyond the standard model. In that context, being able to do an uncertainty quantification of the nuclear-physics calculation becomes somewhat critical. We are particularly interested in exploring this in the context of nuclear beta decays."
"A part of this professorship is also that I will be visiting other nuclear physics groups in Lund and Uppsala and familiarising myself with their work, and I'm really looking forward to that as well."
What are your experiences of Chalmers and Sweden so far?
"This is actually my fourth visit to Chalmers, I’ve been here before for collaborations and conferences, and I wouldn't keep coming back if I didn't like it! There’s a lot of potential for future collaborations on many different subjects. I also really enjoy Gothenburg which is a very nice city with lots of interesting places, and in the summer it's great to get out and visit the islands and the archipelago."
About the Tage Erlander visiting professorship
The Tage Erlander visiting professorship is awarded to an internationally prominent researcher in natural and engineering sciences by the Swedish Research Council. The purpose of the grant is “to give higher education institutions the opportunity to develop a subject area by recruiting an internationally prominent professor during a limited period”.