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**Gravitomagnetic effect and spin-torsion coupling.**
*(English)*
Zbl 1056.83007

The Lense-Thirring gravitational field is similar to a magnetic field. The rotational components of the gravitational field can be named quasimagnetic components, since they lead to effects similar to effects of the magnetic field in electrodynamics. It is well known, that the orbiting time of a particle on corotating and counterrotating orbits (circular and equatorial) differ in general relativity.

The authors of the paper study the effect of torsion on the difference in time of the periods of rotation of a particle on corotating and counterrotating orbits (circular and equatorial) in a gravitational field of a massive and rotating body (Earth). They find that it leads to diminuation of the rotation (Kerr) parameter (dragging of the inertial frames) by \(b< 0.77\%\). Additionally, the authors obtain a correction to the Newtonian gravitational potential, which agrees with the result by M. I. Wanas [Astrophys. Space Sci. 258, No. 1–2, 237–248 (1998; Zbl 0947.83042)].

The result obtained in these two papers differs from the result by Lense and Thirring, obtained very early after the discovery of the General Relativity [see the translation of the original papers by Lense and Thirring published by B. Mashhoon and D. Theiss in [Gen. Relat. Grav. 16, 712 (1984); Mashhoon et al. Ann. Phys. 8, No. 2, 135–152 (1999; Zbl 0919.53030)]. It could be useful to check the computations by use of the metric for a torsion Kerr gravitational field in a Kerr-Schild form [see, e.g. S. Oancea, et al., Studies in gravitation theory, CIP Press, Bucharest (1988)].

The authors of the paper study the effect of torsion on the difference in time of the periods of rotation of a particle on corotating and counterrotating orbits (circular and equatorial) in a gravitational field of a massive and rotating body (Earth). They find that it leads to diminuation of the rotation (Kerr) parameter (dragging of the inertial frames) by \(b< 0.77\%\). Additionally, the authors obtain a correction to the Newtonian gravitational potential, which agrees with the result by M. I. Wanas [Astrophys. Space Sci. 258, No. 1–2, 237–248 (1998; Zbl 0947.83042)].

The result obtained in these two papers differs from the result by Lense and Thirring, obtained very early after the discovery of the General Relativity [see the translation of the original papers by Lense and Thirring published by B. Mashhoon and D. Theiss in [Gen. Relat. Grav. 16, 712 (1984); Mashhoon et al. Ann. Phys. 8, No. 2, 135–152 (1999; Zbl 0919.53030)]. It could be useful to check the computations by use of the metric for a torsion Kerr gravitational field in a Kerr-Schild form [see, e.g. S. Oancea, et al., Studies in gravitation theory, CIP Press, Bucharest (1988)].

Reviewer: Alex Gaina (Chisinau)