Schwinger-Keldysh formalism on the lattice: A faster algorithm and its application to field theory

@article{Alexandru2017SchwingerKeldyshFO,
  title={Schwinger-Keldysh formalism on the lattice: A faster algorithm and its application to field theory},
  author={Andrei Alexandru and Gokce Basar and Paulo F. Bedaque and Gregory W. Ridgway},
  journal={Physical Review D},
  year={2017},
  volume={95}
}
A new algorithm is developed allowing the Monte Carlo study of a 1 + 1 dimensional theory in real time. The main algorithmic development is to avoid the explicit calculation of the Jacobian matrix and its determinant in the update process. This improvement has a wide applicability and reduces the cost of the update in thimble-inspired calculations from O(N^3) to less than O(N^2). As an additional feature, the algorithm leads to improved Monte Carlo proposals. We exemplify the use of the… 
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