# Keldysh formalism

> general framework for describing the quantum mechanical evolution of a system in a non-equilibrium state

**Wikidata**: [Q3748130](https://www.wikidata.org/wiki/Q3748130)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Keldysh_formalism)  
**Source**: https://4ort.xyz/entity/keldysh-formalism


## References

1. Freebase Data Dumps. 2013