Light speed variation from active galactic nuclei

Li, Hao; Ma, Bo-Qiang

doi:10.1016/j.scib.2019.11.024

Cited by 21 publications

(14 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…which is close to the Planck scale E Pl ≃ 1.22 × 10 19 GeV. It is worth noting that such a LV scale ( 7) is consistent with various constraints from high-energy γ-ray observations of pulsars [19], AGNs [21,22,23] as well as GRBs [24,25,26,27,28], and it is also compatible with the strongest robust limit to date from a recent study [29] on 8 Fermi-LAT GRBs. We should mention that there can be severer bounds to E LV from other time-delay studies (see, e.g., Ref.…”

supporting

confidence: 86%

Light Speed Variation in a String Theory Model for Space-Time Foam

Li,

2021

Preprint

Self Cite

View full text Add to dashboard Cite

We revisit a supersymmetric string model for space-time foam, in which bosonic open-string states, such as photons, can possess quantum-gravity-induced velocity fluctuations in vacuum. We argue that the suggestion of the light speed variation recently observed from gamma-ray burst photon time delays can serve as a crucial support for this string-inspired framework, through connecting the experimental finding with model predictions. We also derive the value of the effective quantum-gravity mass in this framework, and give a qualitative study on the model-dependent coefficients. Constraints from birefringent effects and/or photon decays, including the novel γ-decay constraint obtained here from the latest Tibet ASγ near-PeV photon, are also found to be consistent with predictions in such a quantum-gravity scheme. Future observation that can testify further the theory is suggested.

show abstract

supporting

confidence: 86%

Light Speed Variation in a String Theory Model for Space-Time Foam

Li,

2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…[53], time delays between two light curves of different energy bands of PKS 2155-304 were used to give a lower bound of E LIV > 7.2 × 10 17 GeV. However a latest work [55] points out a novel way to understand the delays which can be considered as a signal for the light speed variation with E LIV ≃ 3.6 × 10 17 GeV, i.e., Eq. (21).…”

Section: Velocity Dispersion Of Light In the D-particle Quantumgravitational Foam Mediummentioning

confidence: 99%

Light speed variation with brane/string-inspired space-time foam

2021

Results in Physics

Self Cite

View full text Add to dashboard Cite

Recently a series of studies on high energy gamma-ray burst (GRB) photons suggest a light speed variation with linear energy dependence at the Lorentz violation scale of 3.6 × 10 17 GeV, with subluminal propagation of high energy photons in cosmological space. We propose stringy space-time foam as a possible interpretation for this light speed variation. In such a string-inspired scenario, bosonic photon open-string travels in vacuo at an infraluminal speed with an energy dependence suppressed by a single power of the string mass scale, due to the foamy structure of space-time at small scales, as described by D-brane objects in string theory. We present a derivation of this deformed propagation speed of the photon field in the infrared (IR) regime. We show that the light speed variation, revealed in the previous studies on GRBs time-delay data, can be well described within such a string approach towards space-time foam. We also derive the value of the effective quantum-gravity mass in this framework, and give a qualitative study on the theory-dependent coefficients. We comment that stringent constraints on Lorentz violation in the photon sector from complementary astrophysical observations can also be explained and understood in the space-time foam context.

show abstract

“…In fact, intensive studies have been performed on the n = 3 case of Eq. ( 7) based on time of light flight observations of high energy photons from GRBs [15,[26][27][28][29][30][31][32][33] and active galactic nuclei (AGNs) [34]. These researches suggest ξ = E −1 LV , where E LV = 3.6 × 10 17 GeV, see, e.g., Ref.…”

mentioning

confidence: 99%

Threshold anomalies of ultra-high energy cosmic photons due to Lorentz invariance violation

2021

Journal of High Energy Astrophysics

Self Cite

View full text Add to dashboard Cite

Light speed variation from active galactic nuclei

Cited by 21 publications

References 28 publications

Light Speed Variation in a String Theory Model for Space-Time Foam

Light Speed Variation in a String Theory Model for Space-Time Foam

Light speed variation with brane/string-inspired space-time foam

Threshold anomalies of ultra-high energy cosmic photons due to Lorentz invariance violation

Contact Info

Product

Resources

About