Gauge field theory, as the most basic part of the frontier of contemporary physics, is the most basic part of physics, just like Newtonian mechanics, Maxwell electromagnetic theory, special relativity, general relativity and quantum mechanics. It can accurately describe the electromagnetic force, weak action and strong action among the four basic forces in nature, and gravity can also be described by it, which can be said to be the essence of human understanding. In fact, Dirac combined quantum mechanics with special relativity to establish quantum field theory, and quantum electrodynamics was completed by renormalization. When quantum electrodynamics was successfully extended to nuclear interaction, the idea of Weil gauge theory revived and the modern gauge field theory with Young-Mills theory as the core was formed. On this basis, the so-called standard model of particle physics is formed. Therefore, the core of modern quantum field theory is gauge field theory. "As the most successful physical framework to describe the subatomic world, quantum field theory is unparalleled in both computing power and concept coverage. 8>, it can accurately explain three of the four known fundamental forces in the universe. As a successful subatomic force theory, quantum field theory is mainly embodied in the so-called standard model today. In fact, there is no known experiment (except gravity) that cannot be deduced from the standard model "(Michio kaku 1993). It is precisely because of the success of gauge field theory and the situation of theoretical physics that we can't find a theoretical framework to understand the experimental data, and it has become a situation that if the theory put forward by physicists is newer than the standard model, it will exceed the current level of experimental technology and cannot be tested. It can be seen that gauge field theory must be a great progress in the history of human cognition, and it must have its profound metaphysical foundation, great epistemological significance and scientific methodological significance.

Physical essence of introducing covariant derivative into gauge field theory

Physical essence of introducing covariant derivative into gauge theory

Keywords: matter wave, gauge field, invariance, physical essence

Author: Zhao Guoqiu

Summary: It is generally believed that the interaction between particles and fields is realized by introducing gauge fields. In fact, through the local gauge transformation of free particles, particles are automatically placed in the field interaction. When the global gauge transformation of free particles is transformed into local gauge transformation, the field interaction changes from "nothing" to "existence", and the gauge invariance is destroyed. The introduction of gauge field through covariant derivative reflects the role of particles and fields, but that is to let.

Normative theory

Now, the weak force and electromagnetic force have merged, and the next goal is the strong interaction force. As we have already introduced, so far, this region is dominated by quantum chromodynamics. Fortunately, although the situation is tense and the war is imminent, the monarchs of the two countries are somewhat related by blood, which leaves room for peaceful reunification: both of them are completed under the unified framework of quantum field theory. 1954, Yang Zhenning and Mills established gauge field theory. After absorbing symmetry breaking's thought, some massless particles in the theory can gain mass spontaneously. Because of this, intermediate bosons and photons can be included in the same framework by glashow and others. On the other hand, quantum chromodynamics itself is modeled after quantum electrodynamics, and even its name is modeled after the latter! The difference is that photons have no charge, while gluons have "color" charges. However, if we fully consider the gauge field of spontaneous symmetry breaking, it is not impossible to extend the theory to a larger single group and pull gluons together. This theory is proudly called "GUT", which has developed several variants, but in any case, its goal is the same, that is, to unify the three forces of weak interaction, strong interaction and electromagnetic force into the same theory. Different grand unified theories predict some different physical phenomena, such as the possible decay of protons, such as the existence of magnetic monopoles or strange strings, but unfortunately, these phenomena have not been confirmed conclusively so far. To take a step back, because some key parts of the theory, such as the hypothesis of Higgs boson, have not been discovered in the experiment so far, even our particle standard model can't be 100% sure. But in any case, the grand unification theory is a very promising theory, and people have reason to believe that it will eventually achieve its goal.