John Lipa

Does the renormalization group theory fully represent the behavior of second order phase transitions, or is a deeper theory needed? What is the nature of the supersolid state of matter recently reported at very low temperatures? What are the laws that govern the interplay of time and space?

Experiments on the ground and in space are used to study the superfluid transition of liquid helium, allowing vastly improved tests of the renormalization group theory. Both static and dynamic properties are investigated by Professor Lipa’s group. The apparent supersolid behavior is currently being explored using torsion oscillaotr techniques and plans are being made for a search for a fountain pressure effect, analogous to that in superfluid helium-4 but much smaller in magnitude.

In special relativity, Einstein derived the Lorentz transformation by assuming the constancy of the speed of light. But experimentalists must ask the question: are there small but non-zero violations of the Lorentz transformations that can be detected? In the case of hypothetical Lorentz-violating expressions to the Standard Model, it has been argued that effects might be seen at the 1 part in 10^17 level. Superconducting cavities are being developed for use in high stability microwave oscillators for frequency comparison experiments that would be performed as a function of orientation and velocity relative to the cosmic microwave background.