Unparticle physics

Unparticle physics is a theoretical framework proposed by physicist Howard Georgi in 2007. It focuses on the concept of "unparticles," which are a kind of exotic, scale-invariant matter that does not have a definite mass. This theory suggests that at a certain energy scale, the usual particle description breaks down, and instead, a continuum of degrees of freedom emerges, resembling a "hidden" sector of matter.