A fix for the Cosmological Constant problem?

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I hear that the calculated value of the vacuum energy using QFT is 120 orders of magnitude more than what is observed for the cosmological constant (or vacuum energy). But I wonder if this calculation was done in a very slow locally expanding spacetime. Or was it done with a strictly non-expanding metric? Perhaps when the QFT calculation is done in a very slowly expanding spacetime metric that the calculation might come out more equal to observation. Perhaps the small value of the differential expansion factor ends up multiplying the result and lowers it by 120 orders of magnitude.

Anyone have any insight into these things? Thanks.
 
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  • #2
Kea
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Mike

This is no longer such a mystery. In

Padmanabhan's papers
http://www.iucaa.ernet.in/~paddy/biodata/mylistpub.htm#2006

it is explained how the small number is natural from a certain holographic point of view. Moreover, an analysis of the type IA supernovae data based on a similar entropic viewpoint, made by

L. Riofrio
http://www-conf.slac.stanford.edu/einstein/talks/aspauthor2004_3.pdf

shows good agreement with the data. These are semiclassical pictures for which it is important to view the cosmos from a quantum informational perspective in terms of observer horizons - no magically concrete spacetime.

:smile:
 
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Kea said:
Mike

This is no longer such a mystery. In

Padmanabhan's papers
http://www.iucaa.ernet.in/~paddy/biodata/mylistpub.htm#2006

it is explained how the small number is natural from a certain holographic point of view. Moreover, an analysis of the type IA supernovae data based on a similar entropic viewpoint, made by
Sorry, but I'm not able to open this type of file. Can you point me to a free application that opens these types of files? Thanks.

Off hand I would think that holographic and entropic view points seem to be global consideration and do not seem to address the local QFT calculation of the matter. Does this sound right to you?

L. Riofrio
http://www-conf.slac.stanford.edu/einstein/talks/aspauthor2004_3.pdf

shows good agreement with the data. These are semiclassical pictures for which it is important to view the cosmos from a quantum informational perspective in terms of observer horizons - no magically concrete spacetime.

:smile:
There does not seem to be a date of publication on this paper. Can you tell me how old it is? Do I read this right in that it is saying there is no acceleration in the expansion of the universe as was first suggested by the '98 supernovae data because the speed of light has changed over time? This seems quite controversal. Can you tell me what kind of reception this paper or authors have gotten? Thanks.
 
  • #4
Chronos
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The 120M energy density problem is a quantum theory anomaly, and example of where QT predictions butt heads with GR. Since energy and mass are interchangeable under GR, the QT predicted energy density of the vacuum would result in a closed universe - and one that collapsed a long time ago at that. This, IMO, is symptomatic of a larger problem with QFT - it does not incorporate time. QFT breaks down at macroscopic scales just as GR does in the quantum realm. I think it suggests both models are approximations. I do, however, very much doubt it is possible to quantize gravity via renormalization as usual procedures. I lean toward GR as closer to correct. A universe without time is unphysical, IMO.
 
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