VU Scientist Prof. G. Gaigalas Helps Solve Long-Standing Physics Anomaly

Prof. Gediminas Gaigalas. Photo by Malmö University.

‘Physics is an old science, there’s so much to do here. The most difficult part is choosing exactly what,’ jokes Vilnius University (VU) scientist Prof Gediminas Gaigalas. His theories and atomic calculation programs are essentially unrivalled. Very often, complex physics projects are simply impossible without his contributions. The latest example is an international study that has finally explained an anomaly that has troubled scientists for many years.

Calculations Few Others Could Perform

The story of this research, which attracted significant attention from the scientific community, began in 2020. Scientists at the Massachusetts Institute of Technology (MIT), while studying isotopes of ytterbium, observed behaviour that contradicted established laws of physics. As they examined how certain atoms in high-energy states decay into electrons and positrons, they found that more such particle pairs were being produced than theory predicted.

For some time, physicists speculated that this anomaly could be linked to a mysterious ‘dark force’ – a term referring to the unknown laws governing dark matter, which is thought to make up around 85% of the universe yet remains poorly understood.

However, an international team of researchers, including Prof. G. Gaigalas from the Institute of Theoretical Physics and Astronomy at VU, proposed a far less mysterious explanation. The anomaly was due to the deformation of the nuclei in the ytterbium isotopes. When these nuclei decay, the distribution of their energy and associated electromagnetic fields changes, which in turn affects the production of electron-positron pairs.

It was Prof. G. Gaigalas who was responsible for describing the properties of these isotopes – a highly specialised task requiring calculations that few scientists in the world are capable of performing.

‘The research group found me because they were looking for people who could perform the atomic calculations part of the research. It essentially couldn’t begin without it. I have created several programs for this purpose, and they are quite popular and widely used. However, in this case, the calculations were so complex, and the results needed to be so precise, that the program had to be custom-improved and adapted specifically for this research,’ he explains.

The professor, who was awarded an honorary doctorate by Malmö University last year, has plenty of reasons to feel confident in his work – his team is one of the best on the planet in the field of atomic theory. This shouldn’t be too surprising. Lithuanians deserve to feel proud of their traditions and the accumulated knowledge of atomic theory.

‘In the case of this research, the team was huge, and the process long and complicated, consisting of many layers. Our atomic calculations were necessary to identify the effects that the experiment had on atoms and their characteristics. All this is extremely difficult to calculate; quantum methods and the like must be employed. Accuracy and precision are critical. It’s a big challenge that few can handle,’ says Prof. G. Gaigalas.

Long-standing Traditions

Those traditions that the scientist speaks of have existed in Lithuania for more than seven decades and were started by the father of Lithuanian theoretical physics, Adolfas Jucys. It was he who founded the atomic theory school and developed its distinctive methods. Today’s physicists continue the work begun by their predecessors.

‘Those works by A. Jucys and his school were truly unique, but unfortunately, they were created in the Soviet Union, which meant that quite little of them reached the West. In other words, the school was robust, but isolated. When the borders finally opened, we made a concerted effort to popularise our methods. I barely knew English, so I went to Oxford and then to the USA. That’s how our international collaborations began,’ explains Prof. G. Gaigalas.

He recalls that what surprised him most then were the differences in understanding the role of science in society. In the Soviet Union, conferences were once intended to showcase how deeply individuals had delved into their topic, while the audience was left to their own devices. If you understand – good, if not, too bad. In the West, presentations were designed to ensure that everyone understands them. Prof. G. Gaigalas adopted this work principle himself.

‘In my case, all theories would be worthless if I couldn’t use them for real calculations that would be useful, used by colleagues from other disciplines. Theories are never enough; useful programs are also needed. What’s the use of having a Ferrari if you don’t know how to drive it? In other words, you must learn how to practically exploit that theory, create a methodology, and refine it. That’s how I started writing programs. At first, I did it alone. Now there are three of us on my team. Consequently, numerous opportunities have opened up for us and continue to emerge. All you have to do is choose the right ones,’ jokes VU physicist.