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EC kills the big bang theory, and black hole nonsense, ie, no singularities. That is why many are horrified to learn of EC, which is a perfectly viable alternative to GR. Cartan was right. Excellent article. 47.201.182.47 ( talk) 14:03, 29 December 2018 (UTC)
EC is standard, but the claims about it requiring non-singular fermions sound like crackpottery. A look at the red shows that the non-singularity is a conjecture. cheers, Michael C. Price talk 01:04, 14 January 2019 (UTC)
reference cheers, Michael C. Price talk 04:10, 16 January 2019 (UTC)
The field equations obtained by varying the Lagrangian with respect to the metric are incorrect, and incorrectly described.
The tensor that results from varying the gravitational Lagrangian with respect to the metric must be symmetric because the metric is symmetric. Also, is not the Ricci tensor, which is the singly-contracted Riemann tensor, and which is generally nonsymmetric in EC.
A better procedure (the correct procedure) is to vary the Lagrangian with respect to the frame field (not the metric), which consists of the translational connection coefficients in affine geometry. I shall denote the frame field by . Varying the Lagrangian with respect to the frame field has two important effects. a) The result is the full non-symmetric Ricci tensor. b) The variation of the matter Lagrangian yields the correct non-symmetric momentum tensor. The momentum tensor of EC must be non-symmetric because its non-symmetric part enables Einstein-Cartan theory to model exchange of intrinsic and orbital angular momentum, which general relativity cannot do (because GR is based on Riemannian geometry where the Ricci tensor must be symmetric, so the momentum tensor must be symmetric).
This computation makes clear that Einstein-Cartan theory is an affine theory, not a metric theory.
I have not commented on this article in about five years. However, the main field equation is wrong, and the description does not correclty describe the incorrect field equation that is in the article. I have responded because of the importance of EC in the future of gravitational physics, despite the strong resistance to it.
As Planck said, âA new scientific truth [that alters the elements of a field] does not triumph by persuading its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.â --Max Planck, âScientific Autobiography and Other Papers,â 1949, p 33-34. Quoted in âThe Structure of Scientific Revolutions,â 4th edition, 2012, by Thomas Kuhn, p 150. Rjpetti ( talk) 15:29, 27 August 2019 (UTC)
I recommend removal of the citation to a writing of Niccolai, Edoardo (recently added by JeppOne ( talk ¡ contribs)), unless it can be supported as reliable and noteworthy.
Please note that there are similar discussions at Talk:Bounded mean oscillation § Recently added citation of writing of Niccolai, Edoardo, Talk:EinsteinâCartan theory § Recently added citation of writing of Niccolai, Edoardo, and Talk:Covariant derivative § Recently added citation of writing of Niccolai, Edoardo. There is also discontinued discussion at User talk:JeppOne § Articles by Niccolai, Edoardo. â Quantling ( talk | contribs) 13:41, 1 May 2023 (UTC)
The article currently has 7/23 references to work by Nikodem J. PopĹawski. Absent secondary references this is WP:UNDUE.
If there are reviews that cite this work they should be summarized and cited (in addition to key primary refs). If there are not reviews then the work is not notable and should be removed. Johnjbarton ( talk) 16:04, 13 March 2024 (UTC)
This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||
|
|
||
This page has archives. Sections older than 720 days may be automatically archived by Lowercase sigmabot III when more than 4 sections are present. |
EC kills the big bang theory, and black hole nonsense, ie, no singularities. That is why many are horrified to learn of EC, which is a perfectly viable alternative to GR. Cartan was right. Excellent article. 47.201.182.47 ( talk) 14:03, 29 December 2018 (UTC)
EC is standard, but the claims about it requiring non-singular fermions sound like crackpottery. A look at the red shows that the non-singularity is a conjecture. cheers, Michael C. Price talk 01:04, 14 January 2019 (UTC)
reference cheers, Michael C. Price talk 04:10, 16 January 2019 (UTC)
The field equations obtained by varying the Lagrangian with respect to the metric are incorrect, and incorrectly described.
The tensor that results from varying the gravitational Lagrangian with respect to the metric must be symmetric because the metric is symmetric. Also, is not the Ricci tensor, which is the singly-contracted Riemann tensor, and which is generally nonsymmetric in EC.
A better procedure (the correct procedure) is to vary the Lagrangian with respect to the frame field (not the metric), which consists of the translational connection coefficients in affine geometry. I shall denote the frame field by . Varying the Lagrangian with respect to the frame field has two important effects. a) The result is the full non-symmetric Ricci tensor. b) The variation of the matter Lagrangian yields the correct non-symmetric momentum tensor. The momentum tensor of EC must be non-symmetric because its non-symmetric part enables Einstein-Cartan theory to model exchange of intrinsic and orbital angular momentum, which general relativity cannot do (because GR is based on Riemannian geometry where the Ricci tensor must be symmetric, so the momentum tensor must be symmetric).
This computation makes clear that Einstein-Cartan theory is an affine theory, not a metric theory.
I have not commented on this article in about five years. However, the main field equation is wrong, and the description does not correclty describe the incorrect field equation that is in the article. I have responded because of the importance of EC in the future of gravitational physics, despite the strong resistance to it.
As Planck said, âA new scientific truth [that alters the elements of a field] does not triumph by persuading its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.â --Max Planck, âScientific Autobiography and Other Papers,â 1949, p 33-34. Quoted in âThe Structure of Scientific Revolutions,â 4th edition, 2012, by Thomas Kuhn, p 150. Rjpetti ( talk) 15:29, 27 August 2019 (UTC)
I recommend removal of the citation to a writing of Niccolai, Edoardo (recently added by JeppOne ( talk ¡ contribs)), unless it can be supported as reliable and noteworthy.
Please note that there are similar discussions at Talk:Bounded mean oscillation § Recently added citation of writing of Niccolai, Edoardo, Talk:EinsteinâCartan theory § Recently added citation of writing of Niccolai, Edoardo, and Talk:Covariant derivative § Recently added citation of writing of Niccolai, Edoardo. There is also discontinued discussion at User talk:JeppOne § Articles by Niccolai, Edoardo. â Quantling ( talk | contribs) 13:41, 1 May 2023 (UTC)
The article currently has 7/23 references to work by Nikodem J. PopĹawski. Absent secondary references this is WP:UNDUE.
If there are reviews that cite this work they should be summarized and cited (in addition to key primary refs). If there are not reviews then the work is not notable and should be removed. Johnjbarton ( talk) 16:04, 13 March 2024 (UTC)