Off-shell strings I: S-matrix and action
Amr Ahmadain, Aron C. Wall
SciPost Phys. 17, 005 (2024) · published 5 July 2024
- doi: 10.21468/SciPostPhys.17.1.005
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Abstract
We explain why Tseytlin's off-shell formulation of string theory is well-defined. Although quantizing strings on an off-shell background requires an arbitrary choice of Weyl frame, this choice is not physically significant since it can be absorbed into a field redefinition of the target space fields. The off-shell formalism is particularly subtle at tree-level, due to the treatment of the noncompact conformal Killing group SL(2,$\mathbb{C}$) of the sphere. We prove that Tseytlin's sphere prescriptions recover the standard tree-level Lorentzian S-matrix, and show how to extract the stringy $i\varepsilon$ prescription from the UV cutoff on the worldsheet. We also demonstrate that the correct tree-level equations of motion are obtained to all orders in perturbation theory in $g_s$ and $\alpha^{\prime}$, and illuminate the close connection between the string action and the c-theorem.
Cited by 2
Authors / Affiliation: mappings to Contributors and Organizations
See all Organizations.- 1 Amr Ahmadain,
- 1 Aron C. Wall