Book contents
- Frontmatter
- Contents
- Preface
- 1 The point particle
- 2 The classical bosonic string
- 3 The quantum bosonic string
- 4 The light-cone approach
- 5 Clifford algebras and spinors
- 6 The classical superstring
- 7 The quantum superstring
- 8 Conformal symmetry and two-dimensional field theory
- 9 Conformal symmetry and string theory
- 10 String compactification and the heterotic string
- 11 The physical states and the no-ghost theorem
- 12 Gauge covariant string theory
- 13 Supergravity theories in four, ten and eleven dimensions
- 14 Brane dynamics
- 15 D-branes
- 16 String theory and Lie algebras
- 17 Symmetries of string theory
- 18 String interactions
- Appendix A The Dirac and BRST methods of quantisation
- Appendix B Two-dimensional light-cone and spinor conventions
- Appendix C The relationship between S2 and the Riemann sphere
- Appendix D Some properties of the classical Lie algebras
- Chapter quote acknowledgements
- References
- Index
18 - String interactions
Published online by Cambridge University Press: 05 November 2012
- Frontmatter
- Contents
- Preface
- 1 The point particle
- 2 The classical bosonic string
- 3 The quantum bosonic string
- 4 The light-cone approach
- 5 Clifford algebras and spinors
- 6 The classical superstring
- 7 The quantum superstring
- 8 Conformal symmetry and two-dimensional field theory
- 9 Conformal symmetry and string theory
- 10 String compactification and the heterotic string
- 11 The physical states and the no-ghost theorem
- 12 Gauge covariant string theory
- 13 Supergravity theories in four, ten and eleven dimensions
- 14 Brane dynamics
- 15 D-branes
- 16 String theory and Lie algebras
- 17 Symmetries of string theory
- 18 String interactions
- Appendix A The Dirac and BRST methods of quantisation
- Appendix B Two-dimensional light-cone and spinor conventions
- Appendix C The relationship between S2 and the Riemann sphere
- Appendix D Some properties of the classical Lie algebras
- Chapter quote acknowledgements
- References
- Index
Summary
“The pole, yes but under very different circumstances from those expected. Great God this is an awful place and terrible enough for us to have laboured to it without the reward of priority.”
Scott on reaching the South Pole to find the flag of AmundsenThe discovery of string theory is a remarkable story that began as an attempt to understand hadronic dynamics. It was believed that quantum field theory could not account for the dynamics of hadrons and that one might be able to simply write down the S matrix which was to satisfy a set of properties one of which was called duality. An S matrix for initially four, and then any number, of spin-0 particles of the same mass which did satisfy all the desired properties was eventually found. Although it might seem that these S matrix elements could not be of much value, using physical and mathematical consistency, the early pioneers deduced from them the S matrix for the scattering of an infinite number of particles that were identified as those exchanged in the scattering of the spin-0 particles. Eventually these particles were identified with the states of a string. In telling this story in section 18.1 we will also get a good feeling for what string scattering amplitudes look like, what are their properties and, indeed, for string theory itself.
There is no known complete theory of strings that can be used to compute, even as a matter of principle, all their properties. However, there are a number of approaches that can be used to compute the perturbative scattering of strings. One of the earliest and most used approaches involves a sum over the world surfaces swept out by the string and this is the subject of section 18.2.
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- Chapter
- Information
- Introduction to Strings and Branes , pp. 612 - 665Publisher: Cambridge University PressPrint publication year: 2012