But where did it come from? ##\theta(x^0 - y^0)##, right? The restricted Lorentz group (identity-connected part) preserves time orientation, so it's ok to use ##\theta(x^0 - y^0)## in that circumstance. The rest just involves expressing it in momentum space.realanswers said:
Feynman Green's function is a mathematical tool used in quantum field theory to describe the propagation of particles in space and time. It is a solution to the Feynman propagator equation and helps calculate the probability amplitude for a particle to move from one point to another in spacetime.
Expressing Feynman Green's function as a 4-momentum integral allows for a more efficient and elegant way to solve complex problems in quantum field theory. It also allows for a better understanding of the behavior of particles in spacetime and helps in the calculation of scattering amplitudes.
Feynman Green's function is a key concept in quantum mechanics as it helps describe the behavior of particles at the quantum level. It is used to calculate the probability amplitude of a particle to move from one point to another in spacetime, which is a fundamental concept in quantum mechanics.
Yes, Feynman Green's function can be applied to all types of particles, including fermions and bosons. It is a universal tool in quantum field theory that can be used to describe the behavior of particles regardless of their type or properties.
While expressing Feynman Green's function as a 4-momentum integral is a powerful and widely used technique, it may not always be the most efficient method for solving certain problems in quantum field theory. In some cases, alternative methods may be more suitable or necessary to obtain accurate results.