Measuring the Dark Energy Equation of State

Our major goal in studying the dark energy is to understand whether or not the observed cosmic acceleration is caused by a cosmological constant. Fundamental theory provides strategies for distinguishing between a cosmological constant and other forms of dark energy. Measuring the dark energy equation of state will allow us to distinguish between the cosmological constant and a few specific forms of dark energy, and will provide an overall consistency check of our general relativistic, cosmological constant dominated model of the universe. In this work, we summarize the current state of dark energy constraints, identify three useful milestones, and forecast our ability to reach these milestones in the near future.