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arXiv · hep-ph/9703423

Landau equations and asymptotic operation

Fyodor V. Tkachov
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Abstract

The pinched/non-pinched classification of intersections of causal singularities of propagators in Minkowski space is reconsidered in the context of the theory of asymptotic operation as a first step towards extension of the latter to non-Euclidean asymptotic regimes. A highly visual distribution-theoretic technique of singular wave fronts is tailored to the needs of the theory of Feynman diagrams. Besides a simple derivation of the usual Landau equations in the case of the conventional singularities, the technique naturally extends to other types of singularities e.g. due to linear denominators in non-covariant gauges etc. As another application, the results of Euclidean asymptotic operation are extended to a class of quasi-Euclidean asymptotic regimes in Minkowski space.

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Fyodor V. Tkachov. 1997-03-26. Landau equations and asymptotic operation. https://doi.org/10.1142/s0217751x99000348

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