How do inflatons and gravity interact?

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SUMMARY

The discussion centers on the interaction between inflatons and gravity, particularly during the early universe and the current expansion of the observable universe. It highlights that inflatons dominate when gravity is both strong, as immediately after the Big Bang, and weak, as in the present-day expansion. Guth's theory introduces a repulsive form of gravity during inflation, which decays into particles post-inflation. Current models utilize General Relativity, where the inflaton's stress-energy tensor plays a crucial role, but the exact nature of gravity's influence during inflation remains ambiguous.

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  • Understanding of General Relativity
  • Familiarity with the concept of inflatons
  • Knowledge of the Big Bang theory
  • Basic principles of particle physics
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  • Research Guth's theory of repulsive gravity during inflation
  • Explore the implications of negative pressure in inflaton fields
  • Study the current models of accelerated expansion in cosmology
  • Investigate the relationship between black hole density and inflaton behavior
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Pjpic
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Is the theory that inflatons become dominate when gravity is strong (as in right after the big band) and when gravity is weak (as in driving the current expansion of the observable universe)?
 
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The thing that drove inflation in the very early universe, and the thing that is currently driving the accelerating expansion of the universe, are not necessarily the same thing; in fact, in our best current model they aren't.

Also, you need to clarify what you mean by gravity being "strong" or "weak".
 
Matter had not yet come into existence at the time of inflation, so the role of gravity during inflation is not entirely clear. Guth suggests a special case of gravity during inflation - a repulsive form that drives inflation. In his version the energy driving inflation decays into the hot particle soup of the classical big bang.
 
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Pjpic said:
Is the theory that inflatons become dominate when gravity is strong (as in right after the big band) and when gravity is weak (as in driving the current expansion of the observable universe)?
Current models typically make use of General Relativity, with the stress-energy tensor during inflation dominated by the inflaton. That is, inflation models have no change in gravity at all, and the inflaton interacts with gravity just like everything else: through energy, momentum, pressure, and twisting forces.
 
Chronos said:
Matter had not yet come into existence at the time of inflation, so the role of gravity during inflation is not entirely clear. Guth suggests a special case of gravity during inflation - a repulsive form that drives inflation. In his version the energy driving inflation decays into the hot particle soup of the classical big bang.

a) The density of a black hole doesn't create the same effect?

b) Does the energy driving the current expansion decay into particles?
 
Pjpic said:
a) The density of a black hole doesn't create the same effect?
Nope. The inflaton field is a bizarre creature with an unusual stress-energy content. In particular, p \propto -\rho: it is a perfect fluid with a negative pressure. In the limit that p = -\rho/3, the density \rho is constant.

b) Does the energy driving the current expansion decay into particles?
Do you mean the current accelerated expansion? Nobody knows because we lack a well-understood and well-supported model describing this accelerated expansion.

During primordial inflation, yes, that accelerated expansion did end in the production of particles.
 
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