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Spontaneous Inflation and the Origin of the Arrow of Time

Sean M. Carroll, Jennifer Chen

2004 · arXiv

Statistics & probabilityPhysics
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1
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3
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3
Months
3
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From the abstract

We suggest that spontaneous eternal inflation can provide a natural explanation for the thermodynamic arrow of time, and discuss the underlying assumptions and consequences of this view. In the absence of inflation, we argue that systems coupled to gravity usually evolve asymptotically to the vacuum, which is the only natural state in a thermodynamic sense. In the presence of a small positive vacuum energy and an appropriate inflaton field, the de Sitter vacuum is unstable to the spontaneous onset of inflation at a higher energy scale. Starting from de Sitter, inflation can increase the total entropy of the universe without bound, creating universes similar to ours in the process. An important consequence of this picture is that inflation occurs asymptotically both forwards and backwards in time, implying a universe that is (statistically) time-symmetric on ultra-large scales.

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Original HN comments, with labels from simple text rules. A label describes the whole comment and may miss context or irony. Read the discussion to make up your own mind. About the labels

3 selected excerpts · 3 total mentions

nabla9
Neutral mention · rule
Sean Carroll has also proposed two headed arrow of time. If the direction of time is towards increasing entropy, the starting point of time is the lowest entropy configuration in the universe. The arrow of time is pointing away from that point. https://www.preposterousuniverse.com/blog/2004/10/27/the-arr... Spontaneous Inflation and the Origin of the Arrow of Time https://arxiv.org/abs/hep-th/0410270 >Sean M. Carroll, Jennifer Chen >We suggest that spontaneous eternal inflation can provide a natural explanation for the thermodynamic arrow of time, and discuss the underlying assumptions and consequences of this view. In the absence of inflation, we argue that systems…
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coupled to gravity usually evolve asymptotically to the vacuum, which is the only natural state in a thermodynamic sense. In the presence of a small positive vacuum energy and an appropriate inflaton field, the de Sitter vacuum is unstable to the spontaneous onset of inflation at a higher energy scale. Starting from de Sitter, inflation can increase the total entropy of the universe without bound, creating universes similar to ours in the process. An important consequence of this picture is that inflation occurs asymptotically both forwards and backwards in time, implying a universe that is (statistically) time-symmetric on ultra-large scales
Original comment Julian Barbour’s ideas about time and the universe have roamed free of academia
givinguflac
Neutral mention · rule
Ok, well A.) It was clearly a joke. B.) That number was based off the Wikipedia heat death of the universe page reference for this: https://arxiv.org/abs/hep-th/0410270 C.) Regardless of the correct amount of time, no one will be there to verify it. We don't even understand enough yet to say with absolute confidence that heat death is the definitive final outcome of the universe. But thanks for the reply :)
Original comment LHCb unveils new particles

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