Sunday, April 14, 2024

String Theory Didn't Work Out


String theory makes no predictions and has no observational support. It isn't really even really a theory so much as an approach to come up with a theory that no one has managed to set forth yet.

3 comments:

neo said...

any comment on

arXiv:2403.18606 (gr-qc)

Test the Loop Quantum Gravity Theory via the Lensing Effect
Lai Zhao, Meirong Tang, Zhaoyi Xu

modification of the Schwarzschild black hole. In this paper, we calculate the strong/weak gravitational lensing effects under the quantum-corrected black hole model, taking the supermassive black holes M87* and SgrA* as the subjects of study to explore the impact of the quantum correction parameter α on the positions of images and the Einstein ring. Our calculations show that in the case of strong gravitational lensing, the lensing coefficient a¯ increases with an increase in the quantum correction

[Submitted on 7 Dec 2023 (v1), last revised 28 Dec 2023 (this version, v2)]
Shadows of Loop Quantum Black Holes: Semi-analytical Simulations of Loop Quantum Gravity Effects on Sagittarius A* and M 87*
Hong-Xuan Jiang, Cheng Liu, Indu K. Dihingia, Yosuke Mizuno, Haiguang Xu, Tao Zhu, Qiang Wu

In this study, we delve into the observational implications of rotating Loop Quantum Black Holes (LQBHs) within an astrophysical framework.

Loop Quantum Gravity (LQG) effects results in an enlargement of the rings from LQBHs, thereby causing a more circular polarization pattern in the shadow images. We make comparisons with the Event Horizon Telescope (EHT) observations of Sgr\,A∗ and M\,87∗, which enable us to determine an upper limit for the polymetric function P in LQG. T

arXiv:2305.04336 (gr-qc)
[Submitted on 7 May 2023 (v1), last revised 30 Oct 2023 (this version, v2)]
Strong Gravitational Lensing by Loop Quantum Gravity Motivated Rotating Black Holes and EHT Observations
Jitendra Kumar, Shafqat Ul Islam, Sushant G. Ghosh

We investigate gravitational lensing in the strong deflection regime by loop quantum gravity (LQG)-motivated rotating black hole (LMRBH) metrics with an additional parameter l besides mass M and rotation a. The LMRBH spacetimes are regular everywhere, asymptotically encompassing the Kerr black hole as a particular case and, depending on the parameters, describe black holes with one

"Our theoretical analysis suggests that with advancements in future astrophysical observation techniques, it might be possible to test loop quantum gravity theory using the gravitational lensing effect."


LQG makes specific predictions on strong gravitational lensing for the supermassive black holes M87* and SgrA* that can be observed, in principle, by Event Horizon Telescope (EHT) observations or future telescopes.

what if these LQG predictions of gravitational lensing for the supermassive black holes M87* and SgrA* are verified?

isn't this like the original test of GR vs Newton during the 1919 solar eclipse, here GR vs LQG using gravitational lensing

andrew said...

It will probably be a decade or two before our black hole observations are sufficiently precise to make distinctions that fine grained. Conventional GR is a very good description of strong gravitational field physics, and the effect proposed is very subtle.

neo said...


Shadows of Loop Quantum Black Holes: Semi-analytical Simulations of Loop Quantum Gravity Effects on Sagittarius A* and M 87*
Hong-Xuan Jiang, Cheng Liu, Indu K. Dihingia, Yosuke Mizuno, Haiguang Xu, Tao Zhu, Qiang Wu

proposed Event Horizon Telescope (EHT) observations supermassive black holes M87* and SgrA* which is available for observations

do other qg candidates like String Theory might be possible to test might be possible to test loop quantum gravity theory using the gravitational lensing effecttheory using the gravitational lensing effect