Taking Sides on Dark Energy, Rocky Kolb (University of Chicago)

Dark energy appears to be the dominant component of the present mass-density of the Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. While the simplest explanation might be Einstein's cosmological constant, there are other possibilities.  Many feel that nothing short of a revolution in our understanding of physics will be required to solve the dark energy issue. After framing the dark-energy problem, I will discuss possible theoretical solutions, as well as an observational program to study the properties of dark energy.