About this Research Topic
General relativity predicts that the curvature is not only produced by the distribution of mass-energy, but also by its motion. This is similar to electromagnetism, where fields are produced not only by charge distributions but also by currents. Pursuing this analogy, these effects are sometimes called gravitoelectromagnetism. A test gyroscope or a test spin in orbit around a nonrotating spherical body, precesses about its own axis. This is known as the geodetic precession or de-Sitter effect. On the other hand, a test gyro can also precess if it moves in a rotating spacetime. This is known as the frame-dragging effect or Lense-Thirring (LT) precession. The orbital plane of a test particle, which orbits in a rotating spacetime, also precesses due to the frame-dragging effect. This is known as the orbital plane precession or nodal plane precession.
These two important predictions of general relativity were verified by the Gravity Probe B (GPB) satellite-based experiment. In an article published in 2011, it was shown that the measurement of the said effects for Earth is in good agreement with the general relativity predictions. Although the said effects are verified in the weak gravity regime, the direct strong gravity measurement of the same remains elusive. However, there are some indirect ways by which the said effects could be measured in the several astrophysical phenomena. Moreover, these indirect measurements can provide us with various astrophysical parameters which is very important for the research in astrophysics. For example, by measuring the tilting of an inner accretion disc around a black hole, one can calculate the spin parameter of the black hole and the frame-dragging effect.
The primary purpose of this Research Topic of Frontiers in Astronomy and Space Sciences is to collect articles on the broad aspect of the physics of spin precession in the weak as well as the strong gravity regime from a theoretical/observational perspective, and its various astrophysical applications or vice-versa. Articles should be focused on:
1. Effect of spin precession in the various astrophysical spacetimes, e.g., black hole, naked singularity, neutron star, wormhole and other exotic objects.
2. Effect of Lense-Thirring precession on the accretion disk, and the measurement of spin of the accreting object by using the relativistic precession model.
3. Alignment and precession of a black hole misaligned with its accretion disc.
4. Changing the polarization of gravitational waves, and possible measurement of spin of the black hole.
5. Effect of magnetic fields and other related fields on the spin precession.
6. Gravitational analogue of Faraday rotation (which also appears due to the frame-dragging effect) and its possible measurement in the black hole and neutron star spacetime.
7. Pulsar beam precession close to a supermassive black hole.
8. Jet precession.
These two important predictions of general relativity were verified by the Gravity Probe B (GPB) satellite-based experiment. In an article published in 2011, it was shown that the measurement of the said effects for Earth is in good agreement with the general relativity predictions. Although the said effects are verified in the weak gravity regime, the direct strong gravity measurement of the same remains elusive. However, there are some indirect ways by which the said effects could be measured in the several astrophysical phenomena. Moreover, these indirect measurements can provide us with various astrophysical parameters which is very important for the research in astrophysics. For example, by measuring the tilting of an inner accretion disc around a black hole, one can calculate the spin parameter of the black hole and the frame-dragging effect.
The primary purpose of this Research Topic of Frontiers in Astronomy and Space Sciences is to collect articles on the broad aspect of the physics of spin precession in the weak as well as the strong gravity regime from a theoretical/observational perspective, and its various astrophysical applications or vice-versa. Articles should be focused on:
1. Effect of spin precession in the various astrophysical spacetimes, e.g., black hole, naked singularity, neutron star, wormhole and other exotic objects.
2. Effect of Lense-Thirring precession on the accretion disk, and the measurement of spin of the accreting object by using the relativistic precession model.
3. Alignment and precession of a black hole misaligned with its accretion disc.
4. Changing the polarization of gravitational waves, and possible measurement of spin of the black hole.
5. Effect of magnetic fields and other related fields on the spin precession.
6. Gravitational analogue of Faraday rotation (which also appears due to the frame-dragging effect) and its possible measurement in the black hole and neutron star spacetime.
7. Pulsar beam precession close to a supermassive black hole.
8. Jet precession.
Keywords: Black holes, Compact objects, Rotation, Spin precession, Spin-orbit coupling, Spin-spin coupling, Lense-Thirring effect, Accretion disc, Jet precession
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
