Eur. Phys. J. Plus (2022) 137: 20
https://doi.org/10.1140/epjp/s13360-021-02266-2

Regular Article

Light-like propagation of self-interacting Klein–Gordon fields in cosmology

¹ Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, 7491169, Santiago, Chile
² Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, 7491169, Santiago, Chile
³ Departamento de Física, Facultad de Ciencias, Universidad de Chile, 7800003, Santiago, Chile
⁴ Centro de Recursos Educativos Avanzados, CREA, 7500018, Santiago, Chile

^a felipe.asenjo@uai.cl

Received: 1 June 2021
Accepted: 4 December 2021
Published online: 14 December 2021

Abstract

It is showed that complex scalar fields with a self-interaction potential may propagate along null geodesics on isotropic flat Friedmann–Lemaître–Robertson–Walker universes with different time-dependent scale factors. This effect appears for certain kinds of self-interactions only, for different forms of potentials, and even for the massive case.