Supersymmetry and Dualities

TL;DR

This paper explores how duality transformations in string theory relate supersymmetric and non-supersymmetric backgrounds, emphasizing the importance of non-local effects and stringy phenomena in maintaining supersymmetry.

Contribution

It demonstrates that non-local world-sheet effects are essential for restoring supersymmetry at the string level under dualities, revealing the role of parafermions in the superconformal algebra.

Findings

Non-local world-sheet effects restore supersymmetry.

T-duality relates local and non-local algebra realizations.

Stringy effects resolve effective field theory paradoxes.

Abstract

Duality transformations with respect to rotational isometries relate supersymmetric with non-supersymmetric backgrounds in string theory. We find that non-local world-sheet effects have to be taken into account in order to restore supersymmetry at the string level. The underlying superconformal algebra remains the same, but in this case T-duality relates local with non-local realizations of the algebra in terms of parafermions. This is another example where stringy effects resolve paradoxes of the effective field theory. (Contribution to the proceedings of the Trieste conference on S-Duality and Mirror Symmetry; to appear in Nucl Phys B Proc Suppl)