## Abstract

We study chaotic dynamics in preheating after inflation in which an inflaton φ is coupled to another scalar field χ through an interaction. We first estimate the size of the quasi-homogeneous field χ at the beginning of reheating for large-field inflaton potentials V(φ) ≤ V _{0}φ^{n} by evaluating the amplitude of the χ fluctuations on scales larger than the Hubble radius at the end of inflation. Parametric excitations of the field χ during preheating can give rise to chaos between two dynamical scalar fields. For the quartic potential (n ≤ 4, V_{0} ≤ λ/4) chaos actually occurs for in a linear regime before which the backreaction of created particles becomes important. This analysis is supported by several different criteria for the existence of chaos. For the quadratic potential (n ≤ 2), the signature of chaos is not found by the time at which the backreaction begins to work, similar to the case of the quartic potential with g^{2}/λ ≫ 1.

Original language | English |
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Pages (from-to) | 353-371 |

Number of pages | 19 |

Journal | Classical and Quantum Gravity |

Volume | 23 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2006 Jan 21 |

Externally published | Yes |

## ASJC Scopus subject areas

- Physics and Astronomy (miscellaneous)