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Effective Lagrangians and Infinity Cancellations for Open String Theories


Cline, James Michael (1988) Effective Lagrangians and Infinity Cancellations for Open String Theories. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/9vpf-s680.


The covariant path integral formalism for theories of open and closed strings is used to study the first order of string perturbation theory beyond tree level for the closed-string states, in which the string world sheet has the topology of the disk or the real projective plane. We find that scattering amplitudes (in flat spacetime) confirm these surfaces' contribution to the low-energy effective action for the bosonic string theory, as derived by another method, demanding consistency of string propagation in background gravitational and dilaton fields (the "sigma model approach"). However, we are not able to obtain results consistent with this effective action by demanding that amplitudes in a curved background be finite; this is an unresolved puzzle. Decoupling of spurious tachyon states from the superstring S-matrix is discussed, and finiteness of amplitudes for the disk plus projective plane is demonstrated for a large class of external states, when the gauge group is SO(32).

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Physics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Preskill, John P.
Group:Caltech Theory
Thesis Committee:
  • Preskill, John P. (chair)
  • Peck, Charles W.
  • Schwarz, John H.
  • Wise, Mark B.
Defense Date:20 May 1988
Record Number:CaltechTHESIS:01172013-140801181
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7405
Deposited By: Benjamin Perez
Deposited On:18 Jan 2013 15:17
Last Modified:16 Apr 2021 23:23

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