My  interests center mainly on the interface between cosmology and particle physics.  I have very strong interests in the quantum mechanics/field theory involved in inflationary cosmologies.  This has led me to spending a great deal of time developing a formalism that can be used to describe quantum fields in non-equilibrium environments, such as occur during and immediately after an inflationary phase.  This formalism has also had very interesting applications to the so-called Dark Energy problem.

I am currently involved in trying to understand how current and future measurements of the Cosmic Microwave Background Radiation could detect effects coming from Planck-Scale physics, as well as constructing models that describe the so-called Dark Energy component of the Universe.

Selected Publications

"Renormalization of Initial Conditions and the Trans-Planckian Problem of Inflation," by Hael Collins and R. Holman, Phys. Rev. D 71 (2005) 085009.

"Dark Energy from Wet Dark Fluid," by R.Holman and Siddhartha Naidu, submitted to JCAP (2004).

"The Fate of the Alpha-Vacuum," by Hael Collins, R. Holman and Matthew R. Martin, Phys. Rev. D 68 (2003) 124012.

"Are Inflationary Predictions Sensitive to Very High Energy Physics?," by C.P. Burgess, J.M. Cline, F. Lemieux, and R. Holman, JHEP 0302 (2003) 048.

"Radion Induced Brane Preheating," by Hael Collins, R. Holman and Matthew R. Martin, Phys. Rev. Lett.