Speaker
Description
The famous paper [1] by Kawai, Lewellen and Tye (KLT) showed that $n$-closed strings scattering amplitudes at tree-level on the sphere can be calculated and written in terms of $n$-open strings scattering amplitudes on the disk, using well known techniques of complex analysis. Their results can be summarised (schematically) by “$Gravity = (Gauge)^2$”. In the context of Orientifold theories, tree-level scattering amplitudes involving closed string Tachyons were considered in order to extend their relationship with scattering amplitudes of open string Tachyons. String $g_s$-perturbation theory for orientifold theories involves both $oriented$ and $unoriented$ surfaces, having Euler characteristic $\chi = 2 -2g -b-c$ with g-genus, b-boundaries and c-crosscaps. Oriented theories at tree-level are analysed in [1] and [2,3], where only oriented surfaces enter the calculations, respectively Sphere (S2) and Disk (D2). Following [1,2,3], we investigate the less studied tree-level string scattering amplitudes on an unoriented surface, the Real Projective Plane (RP2) [4], and the relation between $n$-closed strings and 2$n$-open strings is found.
