Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Conventions and notation
- 1 Modeling the early universe
- 2 Blowing up the universe: inflation
- 3 Observing perturbative quantum gravity: fluctuations
- 4 Quantizing gravity: canonical approach
- 5 Quantizing gravity: path integral approach
- 6 Linking gravity, quantum theory, and thermodynamics
- 7 Creating space and time: the no-boundary proposal
- 8 Interpreting the wave function
- 9 Transitioning to different spacetimes
- 10 Going deeper yet: stringy cosmology
- Appendix A Constants of nature and cosmological quantities
- Appendix B Picard{Lefschetz theory and saddle-point approximation
- Appendix C Useful functions
- Appendix D Solutions to exercises
- Appendix E Guide to the bibliography
- Bibliography
- Index
10 - Going deeper yet: stringy cosmology
Published online by Cambridge University Press: 02 February 2026
Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Conventions and notation
- 1 Modeling the early universe
- 2 Blowing up the universe: inflation
- 3 Observing perturbative quantum gravity: fluctuations
- 4 Quantizing gravity: canonical approach
- 5 Quantizing gravity: path integral approach
- 6 Linking gravity, quantum theory, and thermodynamics
- 7 Creating space and time: the no-boundary proposal
- 8 Interpreting the wave function
- 9 Transitioning to different spacetimes
- 10 Going deeper yet: stringy cosmology
- Appendix A Constants of nature and cosmological quantities
- Appendix B Picard{Lefschetz theory and saddle-point approximation
- Appendix C Useful functions
- Appendix D Solutions to exercises
- Appendix E Guide to the bibliography
- Bibliography
- Index
Summary
In the final chapter, the basics of string cosmology are introduced. After a lightning review of string theory, the potential existence of extra dimensions is discussed in some detail. A special emphasis is put on the possible observational signatures of towers of massive Kaluza–Klein modes due to their effects during inflation and in the early universe in general. Then branes are presented as solutions to low-energy approximations to string theory. The difficulties with constructing models of brane inflation are illustrated with a specific example. Finally, a collision of end-of-the-world branes as a model of the big bang is analyzed.
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- Chapter
- Information
- Quantum CosmologyAn Introduction, pp. 303 - 332Publisher: Cambridge University PressPrint publication year: 2026
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