Vacuum birefringence QFT treatment

[Mordred]

Evidence for vacuum birefringence from the rst optical polarimetry measurement of the isolated neutron star RX J1856.5−3754
https://www.google.ca/url?sa=t&sour...LibV7MEMcK__s9nMQ&sig2=AtNYaP5WqBse-GHyQk-FCw

I'm looking for the QFT treatment of the above paper.
Anyone know of any good resources. I don't like the web search explanations I've been running across especially wiki in this case. The arxiv paper above doesn't have the details I'm looking for. Not sure how far to trust the findings in the above paper lol. Doesn't have the details I would consider trustworthy

The QFT articles I've been studying don't have details on this. PS don't worry about math complexity the more detail the better

 

[Mordred]

update found the details I needed, though not through any papers directly related to the above.

Feel free to close this thread if preferred