# Reference for how virtual particles gravitate?

I was reading the slides from an interesting talk by Raphael Bousso. On slide 12 he wrote:

Virtual particles contribute different fractions of the mass of different materials (e.g., to the nuclear electrostatic energy of aluminum and platinum) I If they did not gravitate, we would have detected this difference in tests of the equivalence principle (in this example, to precision $10^6$)

I was wondering if there is a good reference which discusses this in more detail?

• Consider this question about what virtual particles really are. – Robin Ekman Jan 4 '17 at 1:55
• @RobinEkman I don't see how that question relates to my question. – Virgo Jan 4 '17 at 1:59
• "Virtual particles" are internal lines in Feynman diagrams, which are tools for perturbative calculations. That's all they are, nothing more. You should not reify them too much. See the extended discussion here (that was the question I intended to link in the first place...) – Robin Ekman Jan 4 '17 at 2:05
• They should gravitate, as any particles are coupled to gravitons. But the probabilities would be very low. – Drake Marquis Jan 4 '17 at 2:50
• @Virgo, if your question claims to answer itself it is not a question. But that aside, what Robin Exkman is saying that they do contribute to terms in a perturbative calculation, and as such are as real as the results of the calculations. I'd suspect that is what Bousso means but have not seen his slides. Those terms serve to get you for instance from the naked mass of a particle to the final physical mass, and of course gravity is from its final physical mass.you could say they contribute, but careful not to believe those are real, it's the the set of self interactions you have to account for – Bob Bee Jan 4 '17 at 2:51

## 1 Answer

Bousso himself discusses it in his TASI lectures on the cosmological constant. See section 2.3 and references therein.

• Thanks, I think your link is broken. But anyway Bousso just references arxiv.org/abs/hep-th/0603249 where the issue is discussed in Sec 1.1. – Virgo Jan 4 '17 at 3:28