Why do we need the inflaton to expland space-time?

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    Inflaton Space-time
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Discussion Overview

The discussion revolves around the role of the inflaton field in the expansion of space-time, particularly questioning how a particle field can influence a non-particle entity like space-time. Participants explore concepts related to energy density, pressure, and equations of state in cosmology.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions how a particle field can affect space-time, which is not a particle.
  • Another participant suggests that energy and particle fields have energy mass density, which is equivalent to pressure.
  • A participant inquires whether the relationship is described through an equation of state and expresses uncertainty about why negative fluid pressure would lead to faster expansion of space-time.
  • Another participant mentions the ratio of actual density to critical density and references a thread that discusses some mathematical aspects, noting that gravity assigned as positive pressure would require the cosmological constant to have negative pressure for expansion to occur.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between particle fields, energy density, and space-time expansion, indicating that multiple competing perspectives remain without a clear consensus.

Contextual Notes

Some assumptions about the nature of pressure and density in cosmological models are not fully explored, and the discussion does not resolve the implications of negative pressure on space-time expansion.

fairy._.queen
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Hi all!
Fields associated with a particle affect other particles and their fields and that's ok.
But why would a particle affect the space-time (which is not a particle) making it expand?
Thank you in advance!
 
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Energy/particle fields have energy mass density. Density is equivalent to pressure.
 
You mean through an equation of state?

Also, although I know the Friedmann equations, it is not clear to me why the fluid pressure, should it be negative, would cause the space-time to expand faster.
 
Essentially the ratio of actual density to critical density.
https://www.physicsforums.com/showthread.php?t=694499

this thread shows the math some of the math involved. Though it doesn't cover the equations of state as its a curvature article.

Related articles can be found in the links in my signature

gravity being assigned as positive pressure would need the cosmological constant to be negative pressure to have expansion.
 
Last edited:
Thank you!
 

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