T-duality of NSR superstring: The worldsheet perspective

TL;DR

This paper explores the target space duality symmetry of NSR superstring theory from the worldsheet perspective, demonstrating $O(d,d)$ covariance in equations of motion and vertex operators within a superspace formalism.

Contribution

It extends the $O(d,d)$ duality framework to NSR superstrings, including massive vertex operators, from a worldsheet superspace approach.

Findings

Derived $O(d,d)$ covariant equations of motion for NSR superstring.

Expressed massive vertex operators in an $O(d,d)$ invariant form.

Unified bosonic and fermionic backgrounds in duality transformations.

Abstract

We formulate target space duality symmetry of NSR superstring from the perspectives of worldsheet. The worldsheet action is presented in the superspace formalism in the presence of massless backgrounds. We start from a ${\hat D}$-dimensional target space worldsheet action and compactify the theory on a d-dimensional torus, $T^d$. It is assumed that the backgrounds are independent of compact (super)coordinates. We adopt the formalism of our earlier work to introduce dual supercoordinates along compact directions and introduce the corresponding dual backgrounds. It is demonstrated that combined equations of motion of the two sets of coordinates can be expressed in a manifestly $O(d,d)$ covariant form analogous to the equations of motions for closed bosonic string derived by us. Furthermore, we show that the vertex operators associated with excited massive levels of NSR string can be expressed in an $O(d,d)$ invariant form generalizing earlier result for closed bosonic string.