Cosmic Inflation, the Arrow of Time & Boltzmann Brains
The thermodynamic arrow of time offers a very interesting perspective on cosmic inflation and the tuning problems it is meant to address. My research has explored the connection between these two topics from a variety of angles, and I believe further development of these connections will help us attain a deeper understanding of the cosmos and the role of cosmic inflation.
Some technical publications
- Cosmic Inflation and the Arrow of Time, in "Science and Ultimate Reality: Quantum Theory, Cosmology and Complexity", honoring John Wheeler's 90th birthday. J. D. Barrow, P.C.W. Davies, & C.L. Harper eds. Cambridge University Press (2004) astro-ph/0210527 (This paper is meant to be accessible to a wide range of trained scientists, not just experts in the field. It includes my first written discussion of the connection between inflation and the "Boltzmann Brain" problem.)
- Can the universe afford inflation? hep-th/0405270 Phys. Rev. D70 (2004) 063528 (de Sitter equilibrium picture using "Farhi-Guth-Gnuven" tunneling, also first use of the term "Boltzmann Brain")
- de Sitter equilibrium as a fundamental framework for cosmology (in the proceedings of the DICE2008 conference, Thomas Elze, ed). arXiv:0906.1047
- Eternal Inflation with Arrival Terminals arXiv:1406.7352 Phys.Rev. D91 (2015) 023503
- Tuning, Ergodicity, Equilibrium and Cosmology arXiv:1401.7309 Phys.Rev. D91 (2015) 10, 10351
- Ludwig Boltzmann, On Certain Questions of the Theory of Gases (Nature, Feb 28, 1895, p413) This is the paper where Boltzmann first mentioned the "Boltzmann Brain Problem" (but he does not call it that).
More accessible information
- Maybe time's arrow needs ergodicity as well as entropy (Science News April 1 2014)
- Did the Universe Begin? (Closer to Truth interview)
- My review of Sean Carroll's book on the arrow of time in Physics Today
- Big Brain Theory New York Times 1/15/2008