In mathematics, the classification theorem of finite simple groups, often called the "huge theorem", is an important result of group theory. This theorem states that all finite simple groups can be classified as either cyclic groups, alternating groups, or belonging to a general infinite class of groups of Lie type, etc., or as twenty-six special exceptions. Groups are called sporadic groups. Behind this complex conclusion lie tens of thousands of pages and hundreds of scholarly articles, written gradually between 1955 and 2004 by about a hundred authors.
Simple groups can be viewed as the basic building blocks of all finite groups, just like the prime numbers of the natural numbers.
The proof of the entire classification theorem is very tedious and lengthy, covering many mathematical concepts, such as the Jordan–Hölder theorem, which emphasizes that the structural analysis of ordered groups can be reduced to the problem of simple groups. In contrast to integer factorization, these "building blocks" do not necessarily determine a unique group, since many non-isomorphic groups can have the same constituent series, which results in the expansion problem not having a unique solution.
The classification theorem has applications in many areas of mathematics, especially in the analysis of the structure of finite groups and their effects on other mathematical objects, where problems can often be simplified to finite simple groups. Thanks to the classification theorem, these questions can be answered by examining every class of simple groups and every sporadic group. Daniel Gorenstein's announcement in 1983 that all finite simple groups had been classified was premature, as the information he had obtained about the classification of quasithin groups was incorrect.
Two works by Gorenstein in 1982 and 1983 outlined the low-rank and exotic properties of the proof, while a third volume by Michael Aschbacher et al. in 2011 covered the entire low-rank and exotic properties of the proof. Other cases with feature 2 are included. The entire proof process can be divided into several main parts, including small rank 2 groups, component type groups, and groups with characteristic 2.
Most of the small 2-rank simple groups are small-rank Lie groups with peculiar properties, and also include five alternating groups and several sporadic groups. For example, for groups of 2-rank 0, these are all of odd rank and solvable, as can be seen from the Feit–Thompson theorem.
When a group's centralizer C has a core (O(C)) with respect to some inversion, it is considered to be a component type group. Most of these groups are high-rank peculiar Lie groups and alternation groups.
If every generalized Fitting subgroup F*(Y) of a 2-local subgroup Y is a 2-group, then the group is classified as a group of characteristic type 2. This group is mainly derived from peculiar Lie groups and a few interlaced and sporadic groups.
As time went on, Gorenstein proposed a plan to complete the classification of finite simple groups in 1972. This plan includes up to 16 steps, covering a wide range of situations from the classification of low-rank 2 groups to higher levels. Argument. After a long period of hard work, the final proof was produced, and the existence and uniqueness of various groups were confirmed.
As the academic community continues to move forward, follow-up research on the classification theorem is still ongoing, and the second generation of proofs has begun to appear, which means that mathematicians are still working hard to find more concise proofs, especially for higher-rank The problem of group classification.
As new technologies and methods continue to develop, will we one day be able to find a clearer classification method to simplify this huge result?