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arXiv · 2501.14154

Smoothness of Classical Limit in KMOC Formalism

Pritish Sinha
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Abstract

In this paper, we revisit the smoothness of the classical limit of inclusive observables in the formalism developed by Kosower, Maybee and O'Connell (KMOC). Building on the earlier work [1-3], we prove that the classical limit of three classes of inclusive observables, namely scattering angle, radiative field and angular impulse is smooth and does not suffer from any so-called superclassical divergences at all orders in perturbation. We use scalar QED as a model. Our analysis goes some way in showing that KMOC formalism can be used to compute classical radiation by simply focusing on all the terms that scale as $\hbar^{0}$, as all the terms that scale with inverse power of $\hbar$ vanish. Through this analysis, we have successfully isolated the classes of terms that contribute to the classical limit, thereby allowing direct and more efficient computations of physical observables.

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Pritish Sinha. 2025-01-24. Smoothness of Classical Limit in KMOC Formalism. https://doi.org/10.1103/1jwg-6k41

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