Electromagnetic interaction is one of fundamentals in nature. It plays an important role in the evolution of the space structure of the universe. It the cosmological scale, magnetic field is very important while electric field is relatively less important. In the microscopic scale, the electric energy is much larger than magnetic energy. In macroscopic systems, the electromagnetic energy is rather large and relatively easy to evaluate; on the other hand, however, it is not the case for microscopic systems, for instance, we do not how much the electric field and magnetic field contribute to the total mass of an electron. In the case of high momentum, an electron behaves like a point particle with a large value of mass originated from the electromagnetic field, and in the case of low momentum, it looks like a large wave packet with a very small value of mass originated from electromagnetic field. In this chalk talk, I wish to explain the situation of this phenomenon, and a very simple but useful application related to electromagnetic field to the mass of certain microscopic systems. 


2021.12.01 12:00-13:30


ZIRC (multi-function room on the 4th floor of Siyuan Building)


Professor Yumin Zhao

School of Physics and Astronomy, SJTU


Coulomb energy and magnetic field energy of atomic nucleus

Coulomb energy of charged particles