arXiv subjects

Florian Loebbert

Publications and source records attributed to Florian Loebbert.

39 records · Page 3Linked to original sources

arXiv2011

Exact Superconformal and Yangian Symmetry of Scattering Amplitudes

We review recent progress in the understanding of symmetries for scattering amplitudes in N=4 superconformal Yang-Mills theory. It is summarized how the superficial breaking of superconformal symmetry by collinear anomalies and the renormalization process can be cured at tree and loop level. This is achieved by correcting the representation of the superconformal group on amplitudes. Moreover, we comment on the Yangian symmetry of scattering amplitudes and how it inherits these correction terms from the ordinary Lie algebra symmetry. Invariants under this algebra and their relation to the Grassmannian generating function for scattering amplitudes are discussed. Finally, parallel developments in N=6 superconformal Chern-Simons theory are summarized. This article is an invited review for a special issue of Journal of Physics A devoted to Scattering Amplitudes in Gauge Theories.

hep-th↗

arXiv2010

Symmetries of Tree-level Scattering Amplitudes in N=6 Superconformal Chern-Simons Theory

Constraints of the osp(6|4) symmetry on tree-level scattering amplitudes in N=6 superconformal Chern-Simons theory are derived. Supplemented by Feynman diagram calculations, solutions to these constraints, namely the four- and six-point superamplitudes, are presented and shown to be invariant under Yangian symmetry. This introduces integrability into the amplitude sector of the theory.

hep-th↗

arXiv2009

Exacting N=4 Superconformal Symmetry

Tree level scattering amplitudes in N=4 super Yang-Mills theory are almost, but not exactly invariant under the free action of the N=4 superconformal algebra. What causes the non-invariance is the holomorphic anomaly at poles where external particles become collinear. In this paper we propose a deformation of the free superconformal representation by contributions which change the number of external legs. This modified classical representation not only makes tree amplitudes fully invariant, but it also leads to additional constraints from symmetry alone mediating between hitherto unrelated amplitudes. Moreover, in a constructive approach it appears to fully constrain all tree amplitudes when combined with dual superconformal alias Yangian symmetry.

hep-th↗