New algorithms for finite density QCD

Understand

Recent progress of the complex Langevin method and the Lefschetz thimble in connection with the sign problem is reviewed.

• These methods rely on the complexification of the original field manifold and they allow direct simulations of theories with non-real measures.
• Similarities and differences of the two approaches are pointed out.
• Results using the complex Langevin method, which allows simulations to evade the sign problem in full QCD, are presented.