Actions for QCD-like strings

We introduce a random lattice corresponding to ordinary Feynman diagrams, with 1/p-squared propagators instead of the Gaussians used in the usual strings. The continuum limit defines a new type of string action with two worldsheet metrics, one Minkowskian and one Euclidean. The propagators correspond to curved lightlike paths with respect to the Minkowskian worldsheet metric. Spacetime dimensionality of four is implied not only as the usual critical dimension of renormalizable quantum field theory, but also from T-duality.Comment: 14 pg., plain tex, other formats available at http://insti.physics.sunysb.edu/~siegel/preprints or at ftp://max.physics.sunysb.edu/preprints/siege

Conquest of the ghost pyramid of the superstring

We give a new Becchi-Rouet-Stora-Tyutin operator for the superstring. It implies a quadratic gauge-fixed action, and a new gauge-invariant action with first-class constraints. The infinite pyramid of spinor ghosts appears in a simple way through ghost gamma matrices.Comment: 30 pages, 1 figure, Late

Random lattice strings vs. type IIB matrix models

I comment on a curious relation between Siegel's model of random lattice strings and type IIB matrix model. The comparison of the two theories suggests that there may exist extra terms in the latter which are overlooked in the weak string coupling limit.Comment: 3 pages, latex. Some mistakes have been correcte