Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

WMAP/Planck results confirm than we live in a de Sitter-like phase, i.e., a Universe with positive acceleration or positive cosmological constant! Therefore, I believe that a way to solve the cosmological constant problem could be to extend QFT from Minkowski to de Sitter space. I would not be surprised if our "mistake" to get the theoretical "wrong" value of the cosmological constant is associated to the fact of calculating the vacuum energy in a Minkowskian QFT setting.

My question is: what are the problems that a QFT on de Sitter space faces in order to explain the observed vacuum energy? Could it work?

PS: Does someone know good references about QFT in de Sitter space?

share|improve this question
    
Minor quibble: a de Sitter universe contains no matter. Our universe may be evolving towards being approximately de Sitter in the far future, but at the moment it is not a de Sitter universe. –  John Rennie May 18 '13 at 15:09
    
Thanks! I varied lightly the statement. I know what you mean, but with a non-zero cosmological constant, the Universe is more de Sitter like than Minkowskian! But yes, I was unprecise with "de Sitter Universe". I think I have improved the statement... I hope you will understand what I meant despite of that "bad language"... –  riemannium May 18 '13 at 19:32
add comment

1 Answer

Rie. Like your question. I've been stewing on this for 5 yrs now, but have gotten nowhere. Suggestions. For moral support on the CC, see Carlo Rovelli's great paper:http://arxiv.org/abs/1002.3966. For physics(CC only, no dSS) see Beck: http://arxiv.org/abs/0810.0752

The electron & therefore QED must be involved. Dirac's 1935 paper was first to explore the relations of the electron in deSitter space. At first, it seems ridiculous: dS space is Defined tb devoid of particles & radiation ! However, there is a well defined area in GR w/its own metric, the Schwarzschild-deSitter metric. Combine that w/the infamous model of the Dirac electron as a Kerr-Newman BH & you see where this is going. If dS space can accommodate a BH, who cares if it's an electron ! So the idea is to do QED in dS space. The literature is Huge on QFT in dS space, but not much on QED/dS. Indeed, Planck's refined value of 3.3Gev/m^3 => a new target value for Lambda ~ 1.1E-52/m^2. Do let me know if you have any ideas how to attack this problem.

The 'absence' of radiation & particles in dS space is of course a classical concept & I agree that Unruh & Hawking change the rules. Dirac's 1935 paper was the first, vis a vis the electron & dS space. It transforms the momentum-Dirac eq. over to an angular momentum eq. So is this quon thing your idea ? I confess I've never heard of it. Refs? Anything beats SUSY, & I'm convinced she'll be history after the LHC 2015 run !

share|improve this answer
    
Dear PsiStarPsi, thanks for the reference! Indeed, I must confess I do know the answer to this particular question, but I want to see the reaction to people to a non SUSY q-deformed relation between bosons and fermions due to quon interpolation. About your comments about Dirac, I had no knowledge about them! However, from a modern perspective, there is a reason why the argument that dS is devoid of particles and radiation: the Unruh and Hawking effect! –  riemannium Aug 18 '13 at 9:53
    
$T_{Unruh }(dS)=\sqrt{a+a_0}/2\pi$ for a dS spacetime "proves" that even in a "vacuum" spacetime like-de Sitter, the issue of being "radiation-less" is observer dependent! In general, any accelerated system and its observer will "see" radiation even in "vacuum" spacetimes like dS! –  riemannium Aug 18 '13 at 10:41
    
PsiStarPsi The quon idea is not mine! Unfortunately! Read Jack Ng papers and talks about infinite statistics and references therein. Even M-theory and branes have arrived to that crazy uncommon stuff. Even more, do you believe that there are generalized non-additive statistics that change the usual "naive" Boson-Fermion (even anyons) distinction a bit "fuzzy"...Indeed, C.Tsallis has proved recently that you can "recover" S~V for the BH idea through a nonextensive argument! I can not believe no one has realized that before. Holography can be "a disguise" of non-additive entropies! –  riemannium Sep 3 '13 at 14:44
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.