Light-cone gauge string field theory in noncritical dimensions

Abstract

We study light-cone gauge string field theory in noncritical space-time dimensions. Such a theory corresponds to a string theory in a Lorentz noninvariant background. We identify the worldsheet theory for the longitudinal coordinate variables X ± and study its properties. It is a CFT with the right value of Virasoro central charge, using which we propose a BRST invariant formulation of the worldsheet theory.

On finite-size d-branes in superstring theory

“…While we considered the specific case of the D(-1)-D3 brane bound state in this paper, our approach applies equally well to generic Dp-D(p + 4) brane bound states. Another interesting extension concerns the blow up of orbifold singularities in closed super string field theory [34][35][36][37]. We hope to come back to this question in the near future.…”

Multiloop amplitudes of light-cone gauge NSR string field theory in noncritical dimensions

“…The light-cone gauge amplitudes for superstrings suffer from the so-called contact term divergences [18,19,20]. Up to these problems, the equivalence of the amplitudes for the two approaches are shown in [21] when all the external lines are in the (NS,NS) sector for Type II superstrings or in the NS sector for heterotic strings 2 .In [25,26,27], we show that the contact term divergences are regularized by dimensional regularization.Light-cone gauge string field theory can be formulated in noncritical dimensions or taking the worldsheet theory for the transverse variables to be the one with central charge c = 12. One convenient choice of the worldsheet theory is that in a linear dilaton background Φ dilaton = −iQX 1 , with a space-like direction X 1 and a real constant Q .…”

Worldsheet theory of light-cone gauge noncritical strings on higher genus Riemann surfaces

“…It should be possible to find the worldsheet theory in the conformal gauge describing such a string theory, in which the spacetime Lorentz invariance shall be broken. In [1,2], we have constructed the longitudinal part of the worldsheet theory which we call the X ± CFT. The X ± CFT turns out to be a conformal field theory with the right central charge so that the whole worldsheet theory is BRST invariant.…”

“…As has been shown in [1,12], the amplitudes in d = 26 dimensions can be cast into the conformal gauge expression using the worldsheet theory with the field contents X + , X − , X i , b, c,b,c , (2.1) in which the reparametrization ghosts b, c,b,c and the longitudinal variables X ± are added to the original light-cone variables X i (i = 1, . .…”