Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
Many experiments are seeking to constrain the “dark energy” that drives contemporary cosmological acceleration using a variety of techniques. One of the techniques with the greatest potential is weak gravitational lensing. Gravitational lensing by large-scale structure in the Universe has the statistical power to constrain the dark energy equation of state to better than 1%. One of the greatest challenges to this program is systematic errors. On the theory side, the largest systematic error is incurred by the uncertain effects of baryons during galaxy formation on predictions of the lensing power spectrum. In this seminar, Dr. Zentner will review the cosmological acceleration problem and discuss the manner in which gravitational lensing may constrain dark energy and/or other causes of cosmological acceleration. He will then discuss the challenge posed by baryonic effects and a variety of efforts to handle these challenges. Baryonic effects on lensing are uncertain precisely because the process of galaxy formation and evolution remains poorly understood. Dr. Zentner will argue that forthcoming lensing measurements will have the power to constrain dark energy and the physics of galaxy formation in unique and powerful ways.