為表彰他們發現宇宙膨脹的速度在增加，顯示即使沒有物質與任何輻射，空間的能量密度仍然大於零。
索爾．普密特，亞當．利斯 與 布萊．施米茲獲得2006年邵逸夫天文學獎是為了表彰他們率領了兩組研究員，驚人地發現宇宙膨脹速度在增加。雖然愛因斯坦早在剛創建廣義相對論以後即曾討論過此可能，但是他始終認為那只是數學上的可能，與現實宇宙無關。以後的宇宙學家們完全同意他的看法。所以1998年兩組研究員的發現震驚了整個科學界。此發現將會革新我們對物理世界的了解，與對宇宙的未來的預測。
Einstein replaced Newton’s conception of gravitation as a force with general relativity, which views gravitation as the dynamics of spacetime. In 1917 he applied his theory to the universe as a whole. He made two assumptions: the universe is homogeneous on average and static; and it is closed on itself, a curved volume of space with no boundary. However, Einstein’s equations have no such solutions unless an extra term is inserted that acts as a repulsion to offset the gravitational attraction of matter for itself. Thus were born both modern cosmology and the notion of a cosmological constant, Lambda.
In 1929 Hubble found that the universe is expanding, a feature that Friedmann and Lemaître had shown were necessary consequences of Einstein’s equations if Lambda were zero. There are then three models depending on whether the geometry of space is closed, Euclidean, or open. All three models are characterized by a deceleration in the expansion from a big bang.
