madness said:What is the difference when drawing diagrams in momentum space and position space? In my notes the 2 lowest order diagrams for Compton scattering look quite different in momentum and position space. In position space the internal electron line in the second diagram points horizontally in position space and vertically in momentum space. What does this mean?
The actual diagrams are the same in every basis, only the mathematical expressions representing the diagrams are different. As for your question about the internal electron line: if two diagrams only differ by some sort of rotation of propagator lines, the diagrams are the same (topologically equivalent), since when you write down the mathematical expression for the diagram, all that matters is the relative positioning of vertices and lines. The orientation of lines does not step into equations.madness said:What is the difference when drawing diagrams in momentum space and position space? In my notes the 2 lowest order diagrams for Compton scattering look quite different in momentum and position space. In position space the internal electron line in the second diagram points horizontally in position space and vertically in momentum space. What does this mean?
Feynman diagrams are graphical representations of interactions between particles in quantum field theory. They are important for exam prep because they provide a visual tool for understanding complex concepts and calculations in physics.
In Feynman diagrams, the horizontal axis represents position or time, while the vertical axis represents momentum or energy. This allows for a visualization of the relationship between position and momentum in a given interaction.
Position space in Feynman diagrams refers to the position or time coordinates of particles, while momentum space refers to the momentum or energy of the particles. In other words, position space focuses on the location of the particles, while momentum space focuses on their motion.
Feynman diagrams can be used to calculate the probability of particle interactions and to understand the behavior of particles in different situations. They can also be used to visualize and simplify complex concepts, making it easier to solve problems in exam preparation.
While Feynman diagrams are a useful tool for understanding and solving problems, they do have limitations. They are most effective for studying particle interactions at the quantum level and may not be as useful for macroscopic phenomena. Additionally, they may not always accurately represent real-world interactions and should be used in conjunction with other methods for exam prep.