Saved in:
Bibliographic Details
Main Authors: Anselmi, Damiano, Calcagni, Gianluca
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.05276
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908795147386880
author Anselmi, Damiano
Calcagni, Gianluca
author_facet Anselmi, Damiano
Calcagni, Gianluca
contents Theories with purely virtual particles (fakeons) do not possess a classical action in the strict sense, but rather a "classicized" one, obtained by integrating out the fake particles at tree level. Although this procedure generates nonlocal interactions, we show that the resulting classicized equations of motion are not burdened with the need to specify infinitely many initial conditions. The reason is the inherent link between the fakeonic system and the parent higher-derivative local system: the solution space of the former is an appropriate subspace of solutions of the latter. A somewhat unexpected proviso is that, in order to avoid overcounting, the fakeon prescription must be obtained as a limit or special case of a more generic prescription. Ultimately, the set of degrees of freedom matches physical expectations, the extra ones (ghosts or otherwise) being removed by rendering them purely virtual. We illustrate the counting in simple linear solvable models and provide the general proof. Along similar lines, we analyze Dirac's removal of runaway solutions in classical electrodynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2510_05276
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Classicized dynamics and initial conditions in field theories with fakeons
Anselmi, Damiano
Calcagni, Gianluca
High Energy Physics - Theory
Theories with purely virtual particles (fakeons) do not possess a classical action in the strict sense, but rather a "classicized" one, obtained by integrating out the fake particles at tree level. Although this procedure generates nonlocal interactions, we show that the resulting classicized equations of motion are not burdened with the need to specify infinitely many initial conditions. The reason is the inherent link between the fakeonic system and the parent higher-derivative local system: the solution space of the former is an appropriate subspace of solutions of the latter. A somewhat unexpected proviso is that, in order to avoid overcounting, the fakeon prescription must be obtained as a limit or special case of a more generic prescription. Ultimately, the set of degrees of freedom matches physical expectations, the extra ones (ghosts or otherwise) being removed by rendering them purely virtual. We illustrate the counting in simple linear solvable models and provide the general proof. Along similar lines, we analyze Dirac's removal of runaway solutions in classical electrodynamics.
title Classicized dynamics and initial conditions in field theories with fakeons
topic High Energy Physics - Theory
url https://arxiv.org/abs/2510.05276