Did you read the paper at all? It's pretty accessible. The main component is ultra high energy microwaves, these are generated by relativistic electrons acceler

Did you read the paper at all? It's pretty accessible. The main component is ultra high energy microwaves, these are generated by relativistic electrons accelerated beyond the front of the step leader before it hits the ground. When those electrons penetrate through matter they can release microwaves as they decelerate. They can also cause ionization of the air as well. And these phenomena feed off one another. The microwave radiation then gets trapped inside a bubble of plasma as a standing wave. This is a quasi-stable phenomenon because the microwave energy heats the plasma and thus maintains its own confinement. Interestingly, this model seems to explain the vast majority of observational evidence related to ball lightning, including some of the more bizarre occurrences. It's also testable. The easiest way to test it would be making use of 100GW class microwave emitters, which are just a touch beyond the state of the industry today but should be available soon. And that should make it possible to determine the accuracy of the theory and, if it proves accurate, to further study the properties of ball lightning.