Keldysh formalism
Encyclopedia
In condensed matter physics
, the Keldysh formalism is a general framework for describing the quantum mechanical evolution of a system in a non-equilibrium state, e.g. in the presence of time varying fields (electrical field, magnetic field
etc.). The main mathematical object in the Keldysh formalism is the non-equilibrium Green's function
.
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
, the Keldysh formalism is a general framework for describing the quantum mechanical evolution of a system in a non-equilibrium state, e.g. in the presence of time varying fields (electrical field, magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
etc.). The main mathematical object in the Keldysh formalism is the non-equilibrium Green's function
Green's function
In mathematics, a Green's function is a type of function used to solve inhomogeneous differential equations subject to specific initial conditions or boundary conditions...
.