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:
“A culture may be conceived as a network of beliefs and purposes in which any string in the net pulls and is pulled by the others, thus perpetually changing the configuration of the whole. If the cultural element called morals takes on a new shape, we must ask what other strings have pulled it out of line. It cannot be one solitary string, nor even the strings nearby, for the network is three-dimensional at least.”
—Jacques Barzun (b. 1907)
“she drew back a while,
Then, yielding to the irresistible joy,
With frantic gesture and short breathless cry
Folded his frame in her dissolving arms.
Now blackness veiled his dizzy eyes, and night
Involved and swallowed up the vision; sleep,
Like a dark flood suspended in its course,
Rolled back its impulse on his vacant brain.”
—Percy Bysshe Shelley (1792–1822)
“When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That’s relativity.”
—Albert Einstein (1879–1955)