[Submitted on 30 Oct 2023] MONDified Gravity Martin Bojowald, Erick I. Duque Download PDF
A new class of modified gravity theories, made possible by subtle features of the canonical formulation of general covariance, naturally allows MOND-like behavior (MOdified Newtonian Dynamics) in effective space-time solutions without introducing new fields. A detailed analysis reveals a relationship with various quantum-gravity features, in particular in canonical approaches, and shows several properties of potential observational relevance. A fundamental origin of MOND and a corresponding solution to the dark-matter problem are therefore possible and testable.
Comments: 11 pages Subjects: General Relativity and Quantum Cosmology (gr-qc) Cite as: arXiv:2310.19894 [gr-qc]
Saw it. Busy protecting widows and orphans again and teaching a class to lawyers about how to do law stuff tomorrow, so I haven't had much time to post.
Mildly interesting. I don't follow LQG all that closely, and its a bit technical and theoretical for me.
But it does show similarities with gravitweak unification theories, which is a pretty interesting line of inquiry. See also Woit's new paper "space-time is right handed."
But it does show similarities with gravitweak unification theories, which is a pretty interesting line of inquiry. See also Woit's new paper "space-time is right handed."
he mentioned also on his blog and mitchell porter also
"1. Introduction If one wants to describe fermions coupled to gravity, the metric field does not suffice. Rather, one needs to introduce frame fields, and with them the symmetry under frame rotations, a spin structure and hence a local SL(2, C) symmetry. In this context, as the fermions in the standard model are chiral, it is of special interest to consider chiral formulations of gravity. One example are the variables introduced by Sen [1] and Ashtekar [2, 3, 4] for gravity. The basic variables are a frame field eI and an so(3, 1)"
Ashtekar could describe fermions coupled to gravity and " as the fermions in the standard model are chiral, it is of special interest to consider chiral formulations of gravity"
[Submitted on 30 Oct 2023]
ReplyDeleteMONDified Gravity
Martin Bojowald, Erick I. Duque
Download PDF
A new class of modified gravity theories, made possible by subtle features of the canonical formulation of general covariance, naturally allows MOND-like behavior (MOdified Newtonian Dynamics) in effective space-time solutions without introducing new fields. A detailed analysis reveals a relationship with various quantum-gravity features, in particular in canonical approaches, and shows several properties of potential observational relevance. A fundamental origin of MOND and a corresponding solution to the dark-matter problem are therefore possible and testable.
Comments: 11 pages
Subjects: General Relativity and Quantum Cosmology (gr-qc)
Cite as: arXiv:2310.19894 [gr-qc]
Saw it. Busy protecting widows and orphans again and teaching a class to lawyers about how to do law stuff tomorrow, so I haven't had much time to post.
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https://arxiv.org/abs/2310.19729
https://arxiv.org/abs/2310.19722
https://arxiv.org/abs/2310.19729
ReplyDeletehttps://arxiv.org/abs/2310.19722
Mildly interesting. I don't follow LQG all that closely, and its a bit technical and theoretical for me.
But it does show similarities with gravitweak unification theories, which is a pretty interesting line of inquiry. See also Woit's new paper "space-time is right handed."
But it does show similarities with gravitweak unification theories, which is a pretty interesting line of inquiry. See also Woit's new paper "space-time is right handed."
ReplyDeletehe mentioned also on his blog and mitchell porter
also
"1. Introduction
If one wants to describe fermions coupled to gravity, the metric field does not suffice.
Rather, one needs to introduce frame fields, and with them the symmetry under frame
rotations, a spin structure and hence a local SL(2, C) symmetry. In this context, as the
fermions in the standard model are chiral, it is of special interest to consider chiral
formulations of gravity. One example are the variables introduced by Sen [1] and
Ashtekar [2, 3, 4] for gravity. The basic variables are a frame field eI and an so(3, 1)"
Ashtekar could describe fermions coupled to gravity and " as the
fermions in the standard model are chiral, it is of special interest to consider chiral
formulations of gravity"