https://doi.org/10.1140/epjc/s10052-020-7856-3
Regular Article - Theoretical Physics
Quasinormal modes in kink excitations and kink–antikink interactions: a toy model
Departamento de Física, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235, Recife, PE, 50670-901, Brazil
* e-mail: azadeh.mohammadi@df.ufpe.br
Received:
4
December
2019
Accepted:
18
March
2020
Published online:
2
May
2020
We study excitations and collisions of kinks in a scalar field theory where the potential has two minima with 
symmetry. The field potential is designed to create a square well potential in the stability equation of the kink excitations. The stability equation is analogous to the Schrödinger equation, and therefore we use quantum mechanics techniques to study the system. We modify the square well potential continuously, which allows the excitation to tunnel and consequently turns the normal modes of the kink into quasinormal modes. We study the effect of this transition, leading to energy leak, on isolated kink excitations. Finally, we investigate kink–antikink collisions and the resulting scaling and fractal structure of the resonance windows considering both normal and quasinormal modes and compare the results.
© The Author(s), 2020
