Thread by @BradleyKavanagh

Gravitational corrections to the value of the muon #gminus2 - a quick roundup.

It all started with this paper - arxiv.org/abs/1801.10246 - the 3rd in a trilogy. Claimed that a correction due to Earth's gravity should alleviate tension between theory and experiment:

In a blog post - motls.blogspot.nl/2018/02/experi… - @lumidek points out (among other things) that if you're considering corrections due to the gravitational potential, the Sun's potential should dominate, not the Earth's

On twitter (and in a blog post) - realselfenergy.blogspot.nl/2018/02/update… - @PitifulRed offers a short proof of why the gravitational correction must be zero.

Even if you accept that the gravitational correction exists, there are a number of claims (though not always fleshed out) that a mistake in the interpretation would make the correction about 1000 times smaller than estimated in the paper, e.g.

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Then today on the #arXiv, this paper appeared - arxiv.org/abs/1802.00651 - which reiterates that such a gravitational correction would contradict the equivalence principle in GR.

Though I haven't seen anyone point to the specific mistake in the calculation, there seems to be a growing consensus that the result *cannot be correct*.

Looks like gravitational corrections to the muon #gminus2 are not as large as claimed in the original paper...

Another paper on #arXiv today - arxiv.org/abs/1802.01120 - clarifying how these 'corrections' would appear in a #gminus2 experiment

Even if you accept the calculation, these corrections would be much too small to measure (and are already taken into account in the systematics...)