Closed strings and the level matching rule

String Theory (Fall, 2010)

Lecture Playlist

  1. The historical origins of string theory

  2. Mathematics of string motion

  3. The energy spectrum of strings

  4. Closed strings and the level matching rule

  5. Bosonic strings

  6. Strings with spin

  7. Fermionic strings and path integrals

  8. Conformal mapping and string scattering

  9. Strings in compact dimensions

  10. T-duality, D-branes and modeling field theories

  11. String theory wrapup

October 11, 2010

 

This lecture starts with a review of Noether’s theorem, which links continuous symmetries with conserved quantities (charges).   The model of a closed string is developed following the earlier procedure for open strings.   The energy spectrum is similar but with a new constraint called the level matching rule linking the energy of waves in each direction around the string that is connected to Noether’s theorem.

Topics: 
  • Why is charge quantized?
  • Noether’s theorem and conserved charges
  • A model of closed strings
  • The energy spectrum of closed strings
  • The level matching rule
References