Definition: You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").
Input: Paragraph- Sent 1: General relativity includes a dynamical spacetime, so it is difficult to see how to identify the conserved energy and momentum.
Sent 2: Noether's theorem allows these quantities to be determined from a Lagrangian with translation invariance, but general covariance makes translation invariance into something of a gauge symmetry.
Sent 3: The energy and momentum derived within general relativity by Noether's presecriptions do not make a real tensor for this reason.
Sent 4: Einstein argued that this is true for fundamental reasons, because the gravitational field could be made to vanish by a choice of coordinates.
Sent 5: He maintained that the non-covariant energy momentum pseudotensor was in fact the best description of the energy momentum distribution in a gravitational field.
Sent 6: This approach has been echoed by Lev Landau and Evgeny Lifshitz, and others, and has become standard.
Sent 7: The use of non-covariant objects like pseudotensors was heavily criticized in 1917 by Erwin Schrodinger and others.
Question: When did the standard approach to energy momentum become criticized?.
Output:
5, 6, 7.