The Accelerating Universe and Dark Energy: Evidence from Type Ia Supernovae

摘要: � 0.1) demonstrate that the Hubble expansion is linear, H0 = 72 ± 8 km s 1 Mpc , and properties of dust in other galaxies are similar to those Milky Way. The light curves high-redshift (z 0.3–1) SNe Ia stretched a manner consistent with space; similarly, their spectra exhibit slower temporal evolution (by factor + z) than nearby Ia. measured luminosity distances as function redshift have shown Universe currently accelerating, probably due presence repulsive dark energy such Einstein’s cosmological constant (�). From about 200 Ia, we find H0t0 0.96 0.04, 1.4M 0.35 0.14. Combining our data results large-scale structure surveys, best fit for M 0.28 0.72, respectively — essentially identical recent WMAP (and having comparable precision). sum densities, 1.0, agrees extensive measurements cosmic microwave background radiation, including WMAP, coincides value predicted by most inflationary models early Universe: flat on large scales. A number possible systematic effects (dust, supernova evolution) thus far do not seem eliminate need > 0. However, during past few years some very peculiar low-redshift been discovered, must be mindful if objects more abundant at high redshifts. Recently, analyses z 1.0–1.7 provide further support current acceleration, give tentative evidence an epoch deceleration. dynamical age estimated 13.1±1.5 Gyr, ages globular star clusters result 13.7 0.2 Gyr. Current projects include search additional confirm deceleration, measurement hundred 0.2–0.8 accurately determine equation state energy, w P/(�c 2 ), whose now constrained range 1.48 < 0.72 95% confidence.