Y. S. Kim's Interest in Elementary Particle Theory
I worry about the following problems in particle physics.

Einstein and Bohr. They met occasionally before and after 1927. Einstein
was interested in how things appear to moving observers while Bohr was worrying
about electron orbit of the hydrogen atom.
They then must have talked about how the orbit appears to a moving observer. However, there does not have any records about how their conversation went. It is thus fun to construct a theory of moving hydrogen atoms. Click here to see what the issues are.
 Feynman's Parton Picture.
What would happen if the bicyle moves with a speed close to that of light?

Gauge Transformations: A particle at rest has three
rotational degrees of freedom. A massless particle has one
helicity degree of freedom and gauge degrees of freedom. The
question then is whether they are two different manifestations
of one covariant entity, as Einstein's energymomentum relation
gives two different relations for massive and massless particles.
 Neutrino Polarization
as a Consequence of Gauge Invariance.
 Lorentz Group: The above three problems are based on
symmetry of the Lorentz group. I made a very heavy investment in
this subject, and wrote many papers on applications of the Lorentz
group to various problems in physics including those in particle
theory and quantum optics.



copyright@2015 by Y. S. Kim, unless otherwise specified.
Photos of Bohr and Einstein are from the AIP Emilio Segre Visual Archives.
Click here for his home page. His Einstein page.