English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

It is shown that the study of the imaginary part and of the correspondingdispersion relations of Feynman graph amplitudes within the differentialequations method can provide a powerful tool for the solution of the equations,especially in the massive case. The main features of the approach areillustrated by discussing the simple cases of the 1-loop self-mass and of aparticular vertex amplitude, and then used for the evaluation of the two-loopmassive sunrise and the QED kite graph (the problem studied by Sabry in 1962),up to first order in the (d-4) expansion.

Differential equations and dispersion relations for Feynman amplitudes. The two-loop massive sunrise and the kite integral