PDA

View Full Version : The deflection of high-energy photons



philippeb8
2018-Jan-13, 03:48 AM
According to the following paper:
https://arxiv.org/pdf/1401.3720.pdf

GR breaks down at high-energies. Is this true or a crackpottery?

antoniseb
2018-Jan-13, 10:28 AM
... Is this true or a crackpottery?
Are those the only two options? Suppose this was something characteristic of a large subset of models and not of others, and was worth investigating to eliminate some models. Basically a lot of String Theory and Loop Quantum Gravity suggest this should be the case (with various parameters still widely unknown). On the other hand, no observation, including the things reported in that 4 year old paper, has clearly shown this. The recent Gravitational Wave & simultaneous GRB seen from merging neutron stars has put a very tight constraint on it, but that doesn't make it crackpottery.

Shaula
2018-Jan-13, 11:50 AM
According to the following paper:
https://arxiv.org/pdf/1401.3720.pdf

GR breaks down at high-energies. Is this true or a crackpottery?
The paper looks like it was a very preliminary result. There was not enough error analysis and the simplifications in the way the gravitational deflection were not necessarily valid (as the author acknowledges).

If there hasn't been a much firmer, peer reviewed result from this work in the last four years (this was a letter, not a paper) I'm not inclined to think it has decisively shown GR breaking down. GR is expected to break down at high enough energies, but the evidence for it is still not there.

philippeb8
2018-Jan-13, 03:22 PM
The paper looks like it was a very preliminary result. There was not enough error analysis and the simplifications in the way the gravitational deflection were not necessarily valid (as the author acknowledges).

Ok thank you very much.



If there hasn't been a much firmer, peer reviewed result from this work in the last four years (this was a letter, not a paper) I'm not inclined to think it has decisively shown GR breaking down. GR is expected to break down at high enough energies, but the evidence for it is still not there.

Ok I'll read more on this.

Jeff Root
2018-Jan-13, 06:40 PM
The PDF won't download for me, and I don't get an error message.

-- Jeff, in Minneapolis

philippeb8
2018-Jan-13, 06:55 PM
The PDF won't download for me, and I don't get an error message.

-- Jeff, in Minneapolis

Try a different browser or try wget if you have Linux. It works on my cell phone.


Sent from my iPhone using Tapatalk