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

  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},
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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    Proceedings of Corfu Summer Institute 2021 "School and Workshops on Elementary Particle Physics and Gravity" — PoS(CORFU2021)
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The numerical sign problem is a major obstacle to thequantitative understanding of manyimportant physical systems with first-principles calculations. Typical examples for such systems include




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For a recently proposed criterion for convergence see