Journal article

Publication year: 2020

Journal: Nuclear Physics B

Volume number: 960

ISSN: 0550-3213

eISSN: 1873-1562

Open access status: Gold

DOI Link: https://doi.org/10.1016/j.nuclphysb.2020.115165

Publisher: Elsevier

Abstract: 
We investigate the dynamic critical behavior of a relativistic scalar field theory with Z(2) symmetry by calculating spectral functions of the order parameter at zero and non-vanishing momenta from first-principles classical-statistical lattice simulations in real-time. We find that at temperatures above the critical point (T > T-c), the spectral functions are well described by relativistic quasi-particle peaks. Close to the transition temperature (T similar to T-c), we observe strong infrared contributions building up. In the ordered phase at low temperatures (T < T-c), in addition to the quasi-particle peak, we observe a soft mode with a dispersion relation indicative of collective excitations. Investigating the spectral functions close to T-c, we demonstrate that the behavior in the vicinity of the critical point is controlled by dynamic scaling functions and the dynamic critical exponent z, which we determine from our simulations. By considering the equations of motion for a closed system and a system coupled to a heat bath, we extract the dynamic critical behavior for two different dynamic universality classes (Models A & C) in two and three spatial dimensions. (C) 2020 The Author(s). Published by Elsevier B.V.

Harvard Citation style: Schweitzer, D., Schlichting, S. and von Smekal, L. (2020) Spectral functions and dynamic critical behavior of relativistic Z₂ theories, Nuclear Physics B, 960, Article 115165. https://doi.org/10.1016/j.nuclphysb.2020.115165

APA Citation style: Schweitzer, D., Schlichting, S., & von Smekal, L. (2020). Spectral functions and dynamic critical behavior of relativistic Z₂ theories. Nuclear Physics B. 960, Article 115165. https://doi.org/10.1016/j.nuclphysb.2020.115165