How does LSST probe the physics of dark energy?
Current observations suggest that most of the energy density of the universe is in some unknown form. Dark energy affects the cosmic history of both the Hubble expansion and mass clustering. If combined, different types of probes of the expansion history and structure history can lead to tight constraints dark energy equation of state and other cosmological parameters. These tight constraints arise because each technique depends on the cosmological parameters or errors in different ways. A unique aspect of LSST as a probe of dark energy and matter is the use of multiple cross-checking probes that reach unprecedented precision. These probes include weak gravitational lens (WL) cosmic shear, baryon acoustic oscillations (BAO), supernovae, and cluster counting — all as a function of redshift. Using the cosmic microwave background as normalization, the combination of these probes can yield the needed precision to distinguish between models of dark energy. In addition, time-resolved strong
