KeldyshContraction.jl

KeldyshContraction.jl is a package for the symbolic derivation of the two-point correlator diagrams in Keldysh-Schwinger field theory. The symbolic quantum field theory algebra is implemented using SymbolicUtils.jl and TermInterface.jl of the JuliaSymbolic ecosystem. The typesystem has been heavily inspired by the second quantization algebra defined in QuantumCumulants.jl. For more details on the implementation see the "symbolic quantum field algebra" documentation page.

In developing this package, the work SciPost Phys. Core 8, 014 (2025) symbolic quantum field algebra was used extensively. Hence, the corresponding conventions and notation are used in this package.