Rubin, D.Linder, E. V.Kowalski, M.Aldering, G.Amanullah, R.Barbary, K.Connolly, N. V.Dawson, K. S.Faccioli, L.Fadeyev, V.Goldhaber, G.Goobar, A.Hook, I.Lidman, C.Meyers, J.Nobili, S.Nugent, P. E.Pain, R.Perlmutter, S.Ruiz-Lapuente, P.Spadafora, A. L.Strovink, M.Suzuki, N.Swift, H.2026-01-012026-01-010004-637Xhttps://hdl.handle.net/1885/733800362The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data-provides a powerful tool for constraining cosmological models. Here we examine particular classes of scalar field, modified gravity, and phenomenological models to assess whether they are consistent with observations even when their behavior deviates from the cosmological constant ?. Some models have tension with the data, while others survive only by approaching the cosmological constant, and a couple are statistically favored over ? cold dark matter. Dark energy described by two equation-of-state parameters has considerable phase space to avoid ? and next-generation data will be required to constrain such physics, with the level of complementarity between probes varying with cosmology.We thank A. Albrecht, R. Caldwell, R. de Putter, S.Weinberg, and C. Wetterich for helpful discussions. This work has been supported in part by the Director, Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. M.K. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG). We thank A. Albrecht, R. Caldwell, R. de Putter, S. Weinberg, and C. Wetterich for helpful discussions. This work has been supported in part by the Director, Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under contract no. DE-AC02-05CH11231. M.K. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG).13enPublisher Copyright: © 2009. The American Astronomical Society. All rights reserved.Cosmology: observationsCosmology: theorySupernovae: generalLooking beyond lambda with the union supernova compilation2009-04-1010.1088/0004-637X/695/1/39167649822598