4-momentum in QFT (quantum field theory) is a mathematical concept that combines the principles of special relativity and quantum mechanics to describe the energy and momentum of a particle. It is a 4-dimensional vector that includes the particle's energy and three components of momentum.
Conservation of 4-momentum is a fundamental principle in QFT that ensures the laws of physics remain consistent and predictable. It is a consequence of the laws of conservation of energy and momentum, which state that these quantities cannot be created or destroyed, only transferred or transformed.
In QFT, 4-momentum is conserved through interactions between particles. This means that the total 4-momentum before and after an interaction must be equal. This is achieved through the exchange of virtual particles, which carry momentum and energy between the interacting particles.
If 4-momentum is not conserved in QFT, it would violate the laws of conservation of energy and momentum, leading to inconsistencies and contradictions in our understanding of the physical world. It would also make it impossible to accurately predict the outcomes of particle interactions.
No, 4-momentum is a fundamental law of physics and cannot be violated in any situation. However, there are certain scenarios, such as in the presence of strong gravitational fields, where the concept of 4-momentum may need to be modified to account for the effects of general relativity.