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Garrulo
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¿How is possible deduce the Lagrangian of the fields of a theory knowing only his Feynman Diagrams?
It's easy to deduce the Lagrangian from the Feynman rules. From the vertex rule you can deduce the interaction Lagrangian, and from the line rule you can deduce the propagator and hence the free Lagrangian.Garrulo said:¿How is possible deduce the Lagrangian of the fields of a theory knowing only his Feynman Diagrams?
I'm not sure I understand the question. Can you give me an example?Garrulo said:But how can I know what operators (differentiation, product, etc...) must have every term from interaction between fields or from the free field terms?
Demystifier said:From the vertex rule you can deduce the interaction Lagrangian
In the books you will probably not find the inverse explanation discussed explicitly. But once you understand how to derive Feynman rules from the Lagrangian, you will be able to solve the inverse problem by yourself. It is very easy to go backwards once you know how to go forwards. But first you need to learn how to go forwards.Garrulo said:No, in the career only explain some Feynman diagrams tree level. I know some of the books but I dont´use for work with Feynman diagramms. But in this books come the inverse explanation too, not only from lagrangian to diagram, the inverse problem too??
TryGarrulo said:Do you know any website when it is explained singlely?? Uffff..my teachers in the career only tell me how convert the diagram in an integration, but no how deduce it from lagrangian. I don´t know if in other universities maybe you will receive better explanations
Thanks
The Lagrangian of fields from Feynman diagrams is a mathematical concept used in quantum field theory to describe the dynamics of particles and fields. It is a function that specifies the interactions between particles and how they change over time.
The Lagrangian of fields is calculated by first determining the Feynman rules for the specific field theory being studied. These rules dictate how to assign mathematical expressions to each vertex and propagator in the Feynman diagram. The Lagrangian is then expressed as a sum of all possible Feynman diagrams, with each diagram contributing a specific mathematical term.
The Lagrangian of fields is a fundamental concept in quantum field theory, as it allows for the calculation of important quantities such as scattering amplitudes and cross sections. It also provides a way to understand the interactions between particles and fields and how they can change over time.
Yes, the Lagrangian of fields can be used in any field theory, as long as the field theory is described by a Lagrangian. This includes theories such as quantum electrodynamics, quantum chromodynamics, and the Standard Model of particle physics.
While the Lagrangian of fields is a powerful tool in understanding quantum field theory, it does have some limitations. It is only applicable to theories that can be described by a Lagrangian, and it does not provide a complete understanding of all physical phenomena. Additionally, the calculations involved in determining the Lagrangian can be complex and time-consuming.