2015/04/10 by Humberto Gomez, Carlos R. Mafra, Oliver Schlotterer
Mathematics · Physics and Astronomy · #Amplitude #Black Holes and Theoretical Physics #Combinatorics #Duality (order theory) #Graviton #Massless particle #Mathematical physics #Mathematics #Particle physics theoretical and experimental studies #Physics #Pure spinor #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Superstring theory #Supersymmetry #Type (biology) #hep-th
paper · pdf · doi:10.1103/physrevd.93.045030
published as Phys. Rev. D 93, 045030 (2016) · 42 pages, harvmac tex
arxiv created 2015/04/10 · openalex publication_date 2016/02/24 · arxiv updated 2016/03/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The low-energy limit of the massless two-loop five-point amplitudes for both type IIA and type IIB superstrings is computed with the pure spinor formalism and its overall coefficient determined from first principles. For the type IIB theory, the five-graviton amplitude is found to be proportional to its tree-level counterpart at the corresponding order in \ensuremathα^\ensuremath'. Their ratio ties in with expectations based on S-duality since it matches the same modular function E5/2 which relates the two-loop and tree-level four-graviton amplitudes. For R-symmetry violating states, the ratio between tree-level and two-loop amplitudes at the same \ensuremathα^\ensuremath'-order carries an additional factor of \ensuremath-3/5. Its S-duality origin can be traced back to a modular form derived from E5/2.