4 research outputs found
Abelian and nonabelian vector field effective actions from string field theory
The leading terms in the tree-level effective action for the massless fields
of the bosonic open string are calculated by integrating out all massive fields
in Witten's cubic string field theory. In both the abelian and nonabelian
theories, field redefinitions make it possible to express the effective action
in terms of the conventional field strength. The resulting actions reproduce
the leading terms in the abelian and nonabelian Born-Infeld theories, and
include (covariant) derivative corrections.Comment: 49 pages, 1 eps figur
Beta-gamma systems and the deformations of the BRST operator
We describe the relation between simple logarithmic CFTs associated with
closed and open strings, and their "infinite metric" limits, corresponding to
the beta-gamma systems. This relation is studied on the level of the BRST
complex: we show that the consideration of metric as a perturbation leads to a
certain deformation of the algebraic operations of the Lian-Zuckerman type on
the vertex algebra, associated with the beta-gamma systems. The Maurer-Cartan
equations corresponding to this deformed structure in the quasiclassical
approximation lead to the nonlinear field equations. As an explicit example, we
demonstrate, that using this construction, Yang-Mills equations can be derived.
This gives rise to a nontrivial relation between the Courant-Dorfman algebroid
and homotopy algebras emerging from the gauge theory. We also discuss possible
algebraic approach to the study of beta-functions in sigma-models.Comment: LaTeX2e, 15 pages; minor revision, typos corrected, Journal of
Physics A, in pres