摘要

We study the spectrum of bosonic strings in the light- like linear dilaton background and find discrete states. These are physical states which exist only at specific values of momentum. All discrete states except one generate spacetime symmetries. The exceptional discrete state corresponds to constraints which are deformations of conservation laws. The constraints resemble those arising from symmetries, and are equally powerful, suggesting that our notion of symmetry should be generalized.

  • 出版日期2008-1