Approaches to the sign problem in lattice field theory

Christof Gattringer, Kurt Langfeld
2016 International Journal of Modern Physics A  
Quantum field theories (QFTs) at finite densities of matter generically involve complex actions. Standard Monte-Carlo simulations based upon importance sampling, which have been producing quantitative first principle results in particle physics for almost fourty years, cannot be applied in this case. Various strategies to overcome this so-called Sign Problem or Complex Action Problem were proposed during the last thirty years. We here review the sign problem in lattice field theories, focussing
more » ... on two more recent methods: Dualization to world-line type of representations and the density-of-states approach.
doi:10.1142/s0217751x16430077 fatcat:6f2zoufbwvg6fdhgalal4d74pe