• Optimisation of Thimble simulations and quantum dynamics of multiple fields in real time 

      Woodward, Simon; Saffin, Paul M.; Mou, Zonggang; Tranberg, Anders (Peer reviewed; Journal article, 2022)
      We apply the Generalised Thimble approach to the computation of exact path integrals and correlators in real-time quantum field theory. We first investigate the details of the numerical implementation and ways of optimizing ...
    • Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles 

      Mou, Zonggang; Saffin, Paul M.; Tranberg, Anders (Peer reviewed; Journal article, 2019-11)
      We follow up the work, where in light of the Picard-Lefschetz thimble approach, we split up the real-time path integral into two parts: the initial density matrix part which can be represented via an ensemble of initial ...
    • Real-time quantum dynamics, path integrals and the method of thimbles 

      Mou, Zonggang; Saffin, Paul M.; Tranberg, Anders; Woodward, Simon (Peer reviewed; Journal article, 2019)
      Direct numerical evaluation of the real-time path integral has a well-known sign problem that makes convergence exponentially slow. One promising remedy is to use Picard-Lefschetz theory to flow the domain of the field ...
    • Simulations of a bubble wall interacting with an electroweak plasma 

      Mou, Zong-Gang; Saffin, Paul M.; Tranberg, Anders (Peer reviewed; Journal article, 2021-02)
      We perform large-scale real-time simulations of a bubble wall sweeping through an out-of-equilibrium plasma. The scenario we have in mind is the electroweak phase transition, which may be first order in extensions of the ...
    • Statistics on Lefschetz thimbles: Bell/Leggett-Garg inequalities and the classical-statistical approximation 

      Tranberg, Anders; Millington, P; Mou, Zonggang; Saffin, Paul M. (Peer reviewed; Journal article, 2021)
      Inspired by Lefschetz thimble theory, we treat Quantum Field Theory as a statistical theory with a complex Probability Distribution Function (PDF). Such complex-valued PDFs permit the violation of Bell-type inequalities, ...