Influences of dark energy and dark matter on gravitational time advancement

Abstract

The effect of dark matter/energy on the gravitational time advancement (negative effective time delay) has been investigated considering a few dark energy/matter models including cosmological constant. It is found that dark energy gives only a (positive) gravitational time delay, irrespective of the position of the observer, whereas a pure Schwarzschild geometry leads to a gravitational time advancement when the observer is situated at a relatively stronger gravitational field point in the light trajectory. Consequently, there will be no time advancement effect at all at radial distances where the gravitational field due to dark energy is stronger than the gravitational field of the Schwarzschild geometry.

Effect of the Cosmological Constant on Light Deflection: Time Transfer Function Approach

“…See [14] for a review and also [15][16][17][18][19][20][21][22][23][24][25]. In addition, for the cosmological constant and cosmological lensing equation, see, e.g., [17,18,26,27]. As we assess the circumstances, the origin of confusion, e.g., the appearance/disappearance of Λ or the coupling/uncoupling with the mass of the central body M, is essentially attributable to the use of the standard geodesic equation of a photon to obtain light deflection due to Λ, because Λ does not appear.…”

Time delay of photons coupled to Weyl tensor in a regular phantom black hole

“…In the present work, in order to obtain a more comprehensive picture of the photons coupled to the Weyl tensor in the regular phantom black hole, we investigate its time delay in both weak and strong deflection gravitational lensing, which is absent in the previous work [88]. These time-domain signals are important for determining the properties of black holes [89][90][91][92][93][94] and probing new physics [95][96][97][98][99][100][101][102].…”

Probing dark matter and dark energy through gravitational time advancement

“…The GTA of photons has been found to be affected by dark matter and dark energy [9] and therefore, at least in principle, the measurements of GTA at large distances can verify the dark matter and a few dark energy models or put upper limit on the dark matter/energy parameters. The measurement of GTA also can be employed to discriminate the Gravity Rainbow (photons of different energies experience different gravity levels) from pure General Relativity [8].…”