The Lagrangian in scalar-tensor theory can be expressed in the Jordan frame in which the scalar field or some function of it multiplies the Ricci scalar, or in the Einstein frame in which Ricci scalar is not multiplied by the scalar field. There exist various transformations between these frames. Despite the fact that these frames have been around for some time there is currently heated debate about whether either, both, or neither frame is a 'physical' frame which can be compared to observations and experiment.
If we perform the Weyl rescaling, then the Riemann and Ricci tensors are modified.
Famous quotes containing the words string, frame and/or einstein:
“The most perfect expression of human behavior is a string quartet.”
—Jeffrey Tate (b. 1943)
“Writing a novel is not merely going on a shopping expedition across the border to an unreal land: it is hours and years spent in the factories, the streets, the cathedrals of the imagination.”
—Janet Frame (b. 1924)
“I found out that a doctor’s wife needs the understanding of an Einstein and the patience of a saint.”
—Daniel Mainwaring (1902–1977)