1

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?

innisfree
  • 15,147
Virgo
  • 2,084
  • Consider this question about what virtual particles really are. – Robin Ekman Jan 04 '17 at 01:55
  • @RobinEkman I don't see how that question relates to my question. – Virgo Jan 04 '17 at 01:59
  • 1
    "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 04 '17 at 02:05
  • I think the content of my question shows they do have a reality to them and are not just a calculational device. – Virgo Jan 04 '17 at 02:08
  • 1
    They should gravitate, as any particles are coupled to gravitons. But the probabilities would be very low. – Drake Marquis Jan 04 '17 at 02:50
  • 1
    @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 04 '17 at 02:51
  • @BobBee my question is asking for a reference explaining how virtual particles gravitate and how this is measured. So I don't think I have implied my question answers itself. I will edit the title which may be a little misleading. – Virgo Jan 04 '17 at 02:57
  • Ok. Understand your question, but you said your question also said they were real. If they don't gravitate they're not real, so ....... – Bob Bee Jan 04 '17 at 03:01
  • My question assumes they do gravitate and asks for a reference explaining how they gravitate. I'm specifically interested in seeing an explicit calculation of how much nuclear electrostatic energy they contribute to aluminum and platinum. – Virgo Jan 04 '17 at 03:04
  • Oh, I read Bousso's slides. I have no problem with virtual particles having physical effects, eg, contributing to mass. A little more abstract when they have some mass-energy density even in vacuum. The rest of his slides take you to the eternal inflation multiverse, and then probabilistically geometry selects for the dark energy we observe. I don't like those large arguments in slides, no details – Bob Bee Jan 04 '17 at 03:34

1 Answers1

1

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

Qmechanic
  • 201,751
innisfree
  • 15,147
  • 1
    Thanks, I think your link is broken. But anyway Bousso just references https://arxiv.org/abs/hep-th/0603249 where the issue is discussed in Sec 1.1. – Virgo Jan 04 '17 at 03:28