Gravitational torsion field is a force field acting on masses and
bodies in translational or rotational motion, which is the second component of
the gravitational field in the Lorentz-invariant
theory of gravitation and in the covariant theory of
gravitation. By its action
the torsion field is similar to magnetic field in electromagnetism (see Maxwell-like gravitational equations). The
term torsion field in this
meaning was introduced by Sergey Fedosin in 1999. [1]
The torsion field dimension in the system of physical
units SI is the same as for frequency, that is s-1.
Torsion field plays an important role in the gravitational model of strong interaction, allowing, among other things, to estimate
radius of the proton. [2] With the help of the torsion field,
equations of gravitational field are written in the same form as Maxwell's
equations. [3]
The torsion field
in Lorentz-invariant theory of gravitation and in covariant theory
of gravitation up to a constant factor corresponds to the strength of so-called
gravitomagnetic field
in gravitoelectromagnetism.
The equations of gravitoelectromagnetism follow from the general relativity (GTR) in the weak field limit, are Maxwell-like gravitational equations and
coincide in their form with the equations of the Lorentz-invariant theory of
gravitation. [4] In this case, the action of the gravitomagnetic
field on test bodies is expressed through an equation similar to the equation
for the Lorentz force in electromagnetism. [5] [6]
Contents·
1 Torsion field
in Lorentz-invariant theory of gravitation o 1.1 Heaviside's equations o 1.2 Rotating
particle in torsion field o 1.3 Gravitational vector potential ·
2 Torsion
field in covariant theory of gravitation ·
3 Torsion field (gravitomagnetic
field) in general theory of relativity ·
4 Effects
associated with torsion field · 5 Analogies with electrodynamics · 6 See also · 7 References ·
8 External links |
In Lorentz-invariant theory of gravitation (LITG) the
force of gravitation is considered as two-component force, which depends on the
gravitational field strength
(gravitational acceleration)
and gravitational
torsion field
:
![]()
where
and
are the mass and
velocity of a body moving in gravitational field.
The
cause of emergence of the torsion field
in LITG is the necessity to comply with the principle of Lorentz covariance for
gravitational field potentials in inertial reference frames. [7]
As the
gravitational field strength, the torsion field contributes to gravitational tensor, gravitational
stress-energy tensor, the energy density of
gravitational field
![]()
where
is the speed of light,
is
the gravitational constant,
as well
as to the vector of energy flux density
of gravitational field or Heaviside vector:
![]()
and to the Lagrangian
for a particle in gravitational field.
Heaviside's equations
Torsion field is included in three of the four
differential Heaviside's equations:
![]()
![]()
where:
·
is the
mass current density,
·
is the
moving mass density,
·
is the
velocity of the mass flux, which creates the gravitational field and torsion
field.
From
the first equation it follows, that the torsion field has no sources, and
hence, the torsion field lines are always closed as in case of magnetic field.
According to the second equation, the torsion field is produced by the motion
of matter and the change in time of gravitational field strength. The third
equation implies effect of gravitational
induction.
According to LITG, the gravitational field strength
and
torsion field
define
the components of real physical gravitational force, which can be substantiated
at the quantum level like electromagnetic force. The torsion field
occurs whenever there is any movement of mass. Since any motion can be
divided into two parts – the rotational and translational, respectively, then
we can talk about two kinds of torsion field. Torsion field outside the
rotating sphere with angular momentum
has a dipole form: [1]
![]()
The presence of 1/2 in the formula for
reflects the fact that
the gravitational moment of axisymmetric body is equal to the half of its
angular momentum. In case of rectilinear motion of a body, the torsion field
equals:
![]()
where
is
velocity of the body,
is the gravitational
field strength of the body at the point where the torsion field
is determined, and the
strength
is taken in view of
propagation delay of gravitational perturbation.
In
general case, the torsion field of
arbitrarily moving point mass can be expressed through gravitational field
strength
produced by it:
![]()
where
is the unit vector,
directed from the point mass to the point where the torsion field is determined, taken at earlier time (see retarded time).
Rotating particle in torsion field
The formula for the moment of force acting on a
rotating particle with the spin
in
torsion field
, is
written as follows:
![]()
Since
the particle is a top with the spin
, then
in the presence of the moment of forces
the
particle would precess along the direction of the field
. This
follows from the equation of rotational motion:
![]()
Since
the moment of forces
is
perpendicular to the spin
and
the torsion
, then
the same is true for the increment of the spin
during
the time
.
Perpendicularity of
and
leads
to precession of the spin of the particle at angular velocity
around direction of
. The
last equality follows from the fact that
, and the quantity
, where
is the angle between
and
, and the increment of the angle
is measured from the
projection of the vector
on the
plane perpendicular to the vector
up to the projection of
the vector
on this plane.
In the
presence of the non-uniform torsion field the particle with the spin
will be dragged to the
region of the stronger field. From the equations of LITG the expression follows
for such force:
![]()
The
mechanical energy of the particle with the spin in torsion field will be equal
to:
![]()
Torsion
field and gravitational field strength are closely related to the potentials of
the field and expressed by the formulas:
![]()
where
is the scalar potential,
– the vector potential
of gravitational field.
The
significance of potentials is in the fact that if a test particle of unit mass is
placed in an external gravitational field, then
will set the additional
energy of such particle due to action of the field, and
is a
part of the generalized momentum of the particle.[8] The vector potential of gravitational field
contributes to the torsion field and gravitational field strength, but the
torsion field is not directly dependent on the scalar potential. When equations
are wrote in four-dimensional form, field potentials form the gravitational four-potential
, and gravitational tensor, which consists of
and
is obtained as the
four-curl of
.
Torsion field in
covariant theory of gravitation
In the covariant
theory of gravitation, the torsion field is described by a three-dimensional vector
whose components define in curved spacetime
three spatial components of independent components of the gravitational
tensor
,
where
is
the gravitational four-potential.
Being a part of the gravitational
tensor, the torsion field is present in all the basic relations for
gravitational field in the covariant theory of gravitation. [9] [10]
The gravitational field
is a vector field for which the corresponding
equations of vector field are valid. In this case, gravitational
field is a component of the general field. [11] The gravitational tensor
is
included in the equation of motion of a point particle or element of matter, [12] [13] in expressions for energy, momentum,
four-momentum, [14] and in the generalized four-momentum of a physical system, [15]
and is also present in formulation of the field
energy theorem. [16]
Since the gravitational
stress-energy tensor is calculated through the
gravitational tensor, the torsion field enters the equation for metric of the
covariant theory of gravitation. For a massive body, the metric tensor was
found inside [17]
and outside this body. [18]
A comparison of field
equations of the covariant theory of gravitation and the general theory of
relativity is carried out in the article. [19]
In contrast to Newtonian mechanics, in the general theory of relativity (GTR), the motion of test particle
(and the rate of clock) in gravitational field depends on whether the body, the
source of the field, rotates or not. The influence of rotation affects even in
the case when distribution of masses in the source in its reference frame does
not change with time (for example, there is cylindrical symmetry with respect
to the axis of rotation). Gravitomagnetic effects in weak fields are extremely
small. In a weak gravitational field and at low velocities of particles we can
consider separately gravitomagnetic and gravitational forces acting on the test
particles, and the strength of gravitomagnetic field and the gravitomagnetic
force are described by the equations similar in the form to corresponding
equations of electromagnetism.
Let us consider the motion of a test particle in the
vicinity of a rotating spherically symmetric body with the mass
and
the angular momentum
. If
the particle with the mass
is
moving at the velocity
(
is
the speed of light), then the particle would be influenced, in addition to the
gravitational force, by the gravitomagnetic
force, directed (like the Lorentz force) perpendicular to both the
velocity and the strength of the gravitomagnetic field
. In the CGS system of physical units we shall
have:
![]()
And if
the rotating mass is located at the origin of coordinates and
is the
radius vector to the observation point, the strength of the gravitomagnetic
field at this point is: [20]
where
is the
gravitational constant.
The
last formula coincides (accurate to a factor of 2 in the denominator) with the
similar formula for the field of magnetic dipole with the magnetic dipole
moment equal to
.
In GTR gravitation is not an independent physical force.
Gravitation in GTR is rather reduced to the curvature of spacetime and is
treated as a geometric effect, and is equated to the metric field. [21] The same geometric meaning is obtained
by the gravitomagnetic field
. Note
that in teleparallel gravity, instead of the curvature of space-time, the main
role is played by the torsion field. [22]
In contrast to this, in LITG it is assumed that the
force of torsion field arises
already in Minkowski space, as a magnetic force. In GTR the equivalent
gravitomagnetic force is considered in the Riemannian space, where gravitation
has tensor, not vector character. Therefore, the spin of gravitons in GTR is
assumed twice greater than in the vector theory of LITG. Hence, in a number of
works on gravitoelectromagnetism in GTR, in the expressions
for the force and the gravitomagnetic field additional numerical factors appear
in comparison with the expressions for the force and torsion field in LITG. For
rectilinear motion of bodies the formulas for torsion field in LITG and in GTR
coincide. [23]
In the case of strong fields and
relativistic velocities, the torsion field cannot be considered separately from
the gravitational field, since dependence of metric tensor on the magnitude of
fields begins to have an effect, and the field equations become interconnected
and nonlinear.. In this case LITG turns into the covariant theory of gravitation (CTG). [24] In weak fields as separate effects of the
torsion field the following effects are considered:
·
Dragging of inertial reference frames. This is
precession of the spin and orbital moments of test particle near the rotating
massive body. In the SI system of physical units the angular velocity of
precession is equal to
and is directed against
the direction of torsion field
.
·
The orbital
Lense-Thirring effect, which leads to precession, that is to the rotation of
the normal of the elliptical orbit of the particle relative to the vector of
gravitational torsion field of the rotating body. This effect is vectorially
added to the standard general relativistic precession of the pericenter
(43" per century for Mercury), which does not depend on the rotation of
the central body. The orbital Lense-Thirring precession was first measured for
the satellites LAGEOS and LAGEOS II.
·
The spin Lense-Thirring
effect (or the Schiff precession) is expressed in the precession of gyroscope,
located near the rotating body. If we consider the gyroscope as a spinning top,
then the axis of this top will periodically change its direction in space with
the precession frequency. Checking this precession was one of the goals of the
experiment of Gravity Probe B,
conducted by NASA in 2005-2007 on the satellite with the orbit passing through
the pole of the Earth. [25] However,
the measurement errors were too large, in the range of 256-128%, impeding the
measurements. [26] The
experimental measurement of the Schiff precession is the test for the theories
of GTR and CTG with respect to the formulas for the precession. At the Earth’s
pole the angular velocity of precession
is directed similarly to
the spin of the Earth
, and
from CTG it follows:
![]()
where
is distance from the
Earth’s center to the gyroscope in the orbit near the pole.
The
same formula for angular velocity of precession is valid in general relativity,
but averaged over the whole orbit. [27] For
the
there is the value 0.0409 arc
seconds per year (here
km for the satellite
Gravity Probe B,
is the Earth's radius,
the altitude of the satellite is 640 km).
·
The geodetic precession
(de Sitter effect) occurs in parallel transport of the angular momentum vector
in curved spacetime. For the Earth-Moon system, moving in the field of the Sun,
the geodetic precession is 1.9" per century; the precise astrometric
measurements revealed this effect, which coincided with the predicted within
the error range of 1 %. The geodetic precession of gyroscopes on the satellite
Gravity Probe B coincided with the predicted value (the rotation of the axis by
6.606 arc seconds per year in the plane of the satellite’s orbit) with the
accuracy more than 1 %. The formula for the de Sitter precession in GTR has the
form: [28]
where
is velocity of motion of
the gyroscope in the orbit of the Earth,
is the mass of the
Earth,
is the orbital angular velocity of the
gyroscope’s rotation.
The
angular velocity of geodetic precession is perpendicular to velocity of
gyroscope and to acceleration of Earth's gravitation, coinciding with the
direction of the orbital angular velocity of rotation. Therefore, at the pole
of the Earth the geodetic precession is perpendicular to the spin precession in
the Schiff effect, the angular velocity of which is directed along the axis of
the Earth’s rotation.
·
The gravitomagnetic time
shift. In the weak fields (for example, near the Earth) this effect is masked
by the standard special and general relativistic effects of the change of the
rate of clock and is far beyond the current accuracy of experiments.
Since the gravitational torsion field is similar to
the magnetic field in electrodynamics, and the angular momentum of a particle
is similar to dipole magnetic moment, then according to LITG it allows us to
interpret the Lense-Thirring effect as
an example of rotation of
electrically charged test particle around a body attracting it, if this body
has the dipole magnetic moment. Due to the law of conservation of the orbital
angular momentum, the orbital plane of the particle tends not to change its
position in space. However, during the rotation of the particle around the
body, the charge of the particle will be influenced by the additional Lorentz
force from the magnetic field of the body, which is perpendicular to the
particle velocity. In the stationary state, the velocity and the orbital
angular momentum of the particle will not change in the magnitude, but the
orbit of the rotating particle and direction of its orbital angular momentum
will precess relative to the axis of dipole magnetic moment of the body, as in
orbital Lense-Thirring effect.
If the particle has its proper magnetic moment and
spin, then there will be interaction of magnetic moments of the particle and
the body. The energy of this interaction depends on the mutual orientation of
magnetic moments. The magnetic field of the body will tend to establish the
magnetic moment of particle in direction of the field, but the particle has the
spin, tending to preserve its direction in space. Therefore there will be
precession of the particle’s spin relative to the axis of dipole magnetic moment
of the body, similar to the Schiff effect.
Another effect is associated with the orbital motion
of a particle with magnetic moment and spin relative to a charged body. In the
rest frame of the center of momentum
of the particle, the particle itself is rotating, and the body is rotating
around this particle. The orbital rotation of charged body creates the magnetic
field acting on magnetic moment of the particle. This leads to the precession
of the magnetic moment and the spin of the particle relative to magnetic field
from the orbital rotation of the body. Now we shall replace the magnetic field
by the torsion of the gravitational field, and the charges by masses. Then it
turns out that the angular velocity of the spin precession of the particle
would be one third of the angular velocity of geodetic precession (the other
two thirds arise from the curvature of spacetime around the body due to
changing of space time metric).
·
Gravitational field strength
·
Maxwell-like gravitational equations
·
Lorentz-invariant theory of
gravitation
·
Covariant theory of gravitation
·
Gravitational
stress-energy tensor
·
Magnetic
field
1.
Fedosin S.G. Fizika i filosofiia podobiia ot preonov
do metagalaktik, Perm, pages 544, 1999. ISBN 5-8131-0012-1.
2.
Fedosin S.G. and Kim
A.S. The Moment of Momentum and the Proton Radius.
Russian Physics Journal, Vol. 45, No. 5, pp. 534-538 (2002). https://doi.org/10.1023/A:1021001025666.
3.
Fedosin S.G. Sovremennye problemy fiziki: v poiskakh novykh printsipov.
Moskva: Editorial URSS, 2002, 192 pages. ISBN 5-8360-0435-8. // Федосин С.Г. Современные
проблемы физики. В поисках новых принципов.
– М., Эдиториал УРСС, 2002, 192 стр., Ил.26, Библ. 50 назв. ISBN
5-8360-0435-8.
4.
Behrooz Malekolkalami
and Mehrdad Farhoudi. About Gravitomagnetism. Modern Physics Letters A. Vol.
24, No. 08, pp. 601-613 (2009). https://doi.org/10.1142/S0217732309028618.
5.
Ruggiero M.L. A Note on
the Gravitoelectromagnetic Analogy. Universe, Vol. 7, 451 (2021). https://doi.org/10.3390/universe7110451.
6.
Nastase H.
Gravitoelectric and gravitomagnetic fields and applications. In: General
Relativity: A Graduate Course. Cambridge University Press, pp. 128-136 (2025). https://doi.org/10.1017/9781009575737.015.
7. Fedosin S.G. Electromagnetic
and Gravitational Pictures of the World. Apeiron, 2007, Vol. 14, No. 4, P.
385 – 413.
8. Fedosin S.G. The
Hamiltonian in Covariant Theory of Gravitation. Advances in Natural
Science, 2012, Vol. 5, No. 4, P. 55 – 75. http://dx.doi.org/10.3968%2Fj.ans.1715787020120504.2023
.
9.
Fedosin S.G. About the cosmological constant, acceleration
field, pressure field and energy. Jordan Journal of
Physics. Vol. 9, No. 1, pp. 1-30, (2016). http://dx.doi.org/10.5281/zenodo.889304.
10. Fedosin
S.G. Lagrangian formalism in the theory of relativistic vector fields.
International Journal of Modern Physics A, (2024). https://doi.org/10.1142/S0217751X2450163X.
11. Fedosin
S.G. Two components of the macroscopic general field. Reports in Advances of
Physical Sciences, Vol. 1, No. 2, 1750002, 9 pages (2017). http://dx.doi.org/10.1142/S2424942417500025.
12. Fedosin
S.G. Equations of Motion in the Theory of Relativistic Vector Fields.
International Letters of Chemistry, Physics and Astronomy, Vol. 83, pp. 12-30
(2019). https://doi.org/10.18052/www.scipress.com/ILCPA.83.12.
13. Fedosin
S.G. Four-Dimensional Equation of Motion for Viscous Compressible and Charged
Fluid with Regard to the Acceleration Field, Pressure Field and Dissipation
Field. International Journal of Thermodynamics. Vol. 18, No. 1, pp. 13-24
(2015). http://dx.doi.org/10.5541/ijot.5000034003.
14. Fedosin
S.G. What should we understand by the four-momentum of physical system? Physica
Scripta, Vol. 99, No. 5, 055034 (2024). https://doi.org/10.1088/1402-4896/ad3b45.
15. Fedosin
S.G. Generalized Four-momentum for Continuously Distributed Materials. Gazi
University Journal of Science, Vol. 37, Issue 3, pp. 1509-1538 (2024). https://doi.org/10.35378/gujs.1231793.
16. Fedosin
S.G. The Integral Theorem of the Field
Energy. Gazi University Journal of Science. Vol. 32, No. 2,
pp. 686-703 (2019). http://dx.doi.org/10.5281/zenodo.3252783.
17. Fedosin
S.G. The relativistic uniform model: the
metric of the covariant theory of gravitation inside a body, St.
Petersburg Polytechnical State University Journal. Physics and
Mathematics (Научно-технические ведомости СПбГПУ. Физико-математические науки),
Vol. 14, No. 3, pp.168-184 (2021). http://dx.doi.org/10.18721/JPM.14313.
18. Fedosin
S.G. The Metric Outside a Fixed Charged Body in the Covariant Theory of
Gravitation. International Frontier Science Letters, Vol. 1, No. 1, pp. 41-46
(2014). http://dx.doi.org/10.18052/www.scipress.com/ifsl.1.41.
19. Fedosin
S.G. Comparison of tensor and vector
theories of gravitation. Iranian Journal of Physics
Research, (2025). Articles in Press, Accepted Manuscript, Available Online from
29 June 2025. https://ijpr.iut.ac.ir/article_3636_5f5bc9308ee52ff299b3b3a67df63b3f.pdf.
20. L. Iorio, H.I.M. Lichtenegger, M.L. Ruggiero, C.
Corda. Phenomenology of the
Lense-Thirring effect in the Solar System. arXiv:1009.3225v2 16 Sep 2010.
21. Professor
R.W.Tucker Publications. Can one measure Spacetime Torsion?,
Proceedings for 60th birthday tribute to J. Azcaragga, Salamanca, Spain, June
2003.
22. Arcos
H.I. and Pereira J.G. Torsion and the gravitational interaction. Class.
Quantum Grav. Vol. 21(22), 5193 (2004). https://doi.org/10.1088/0264-9381/21/22/011.
23. Sergei M. Kopeikin. Gravitomagnetism and the Speed of
Gravity. Int. J. Mod. Phys.D 15:305-320, 2006.
24. Fedosin S.G. Fizicheskie
teorii i beskonechnaia vlozhennost’ materii. – Perm, 2009, 844 pages, Tabl.
21, Pic. 41, Ref. 289. ISBN 978-5-9901951-1-0. (in Russian).
25. Everitt, C.W.F., et al., Gravity Probe B: Countdown to
Launch. In: Laemmerzahl, C., Everitt, C.W.F., Hehl, F.W. (Eds.), Gyros, Clocks,
Interferometers…: Testing Relativistic Gravity in Space. — Berlin, Springer,
2001, pp. 52-82.
26. Muhlfelder, B., Mac Keiser, G., and Turneaure, J.,
Gravity Probe B Experiment Error, poster L1.00027 presented at the American
Physical Society (APS) meeting in Jacksonville, Florida, on 14-17 April 2007,
2007.
27. Yi Mao , Max Tegmark, Alan Guth, Serkan Cabi. Constraining Torsion with Gravity
Probe B. arXiv:gr-qc/0608121v45, Phys. Rev. D. 76, 104029, 2007.
28. N. Straumann, General Relativity and relativistic
Astrophysics, Springer-Verlag, Berlin, Heidelberg, New York, 1991.