The strongest evidence for dark energy at present comes from geometric techniques such as the supernova distance-redshift relation. Because these methods rely on the Friedmann equation, which has not been independently tested, it is desirable to find alternative methods that work for both general relativity and other theories of gravity. This project will develop methods for using large-scale structure, microwave background anisotropy, and weak gravitational lensing measurements, to test models of dark energy, especially models based on modified theories of gravity. A key goal of this research is to develop theories and methods for broad tests of the hypothesis that dark energy is due to modified gravity instead of a cosmological constant or dynamical fluid.
The investigator will involve gifted high school students and undergraduates in the research, along with the training and education of graduate students. The results will also be used to inform the researcher's continuing outreach efforts to university alumni and other non-specialist groups.
