World-Sheet Logarithmic Operators and Target Space Symmetries in String Theory

TL;DR

This paper explores how world-sheet logarithmic operators in string theory relate to target space symmetries, revealing their role in restoring broken symmetries and analyzing their impact on string amplitudes.

Contribution

It provides a target-space interpretation of logarithmic operators and examines their role in generating zero modes and restoring symmetries in string backgrounds.

Findings

Logarithmic operators generate normalizable zero modes in target space.

They help restore symmetries broken by the background.

The paper discusses the recoil problem in string theory.

Abstract

We discuss the target-space interpretation of the world-sheet logarithmic operators in string theory. These operators generate the normalizable zero modes (discrete states) in target space, which restore the symmetries of the theory broken by the background. The problem of the recoil in string theory is considered, as well as some general properties of string amplitudes containing logarithmic operators.