In this Letter, we extend the tree-level Kawai-Lewellen-Tye (KLT) and Bern-Carrasco-Johansson (BCJ) amplitude relations to loop integrands of gauge theory and gravity. By rearranging the propagatorsâ€¦ (More)

The structure of treeâ€“level open and closed superstring amplitudes is analyzed. For the open superstring amplitude we find a striking and elegant form, which allows to disentangle its Î±â€“expansionâ€¦ (More)

We extend the study of scattering amplitudes presented in " The LHC String Hunter's Companion " [1] to the case of five-point processes that may reveal the signals of low mass strings at the LHC andâ€¦ (More)

We present the massless six-point one-loop amplitudes in the open and closed superstring using BRST cohomology arguments from the pure spinor formalism. The hexagon gauge anomaly is traced back to aâ€¦ (More)

We derive local kinematic numerators for gauge theory tree amplitudes which manifestly satisfy Jacobi identities analogous to color factors. They naturally emerge from the low energy limit ofâ€¦ (More)

In this article we present the worldsheet integrand for one-loop amplitudes in maximally supersymmetric superstring theory involving any number n of massless open string states. The polarizationâ€¦ (More)

The N = 1 superconformal circle theory consisting of a free boson and a free fermion is considered. At any radius the theory has standard Dirichlet and Neumann branes, but for rational radii thereâ€¦ (More)

We calculate one-loop string amplitudes of open and closed strings with N = 1, 2, 4 supersymmetry in four and six dimensions, by compactification on Calabi-Yau and K3 orbifolds. In particular, weâ€¦ (More)

Lecture notes on Infinite Dimensional Symmetries given by Hermann Nicolai at the 15th Saalburg summer school in Wolfersdorf, Thuringia, in September 2009. Typed by Oliver Schlotterer.

We present all-multiplicity evidence that the tree-level S-matrix of gluons and gravitons in heterotic string theory can be reduced to color-ordered single-trace amplitudes of the gauge multiplet.â€¦ (More)