301.3E Centralizer of an Element of a Group
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- Опубліковано 22 вер 2018
- The centralizer of an element a in a group G is the set of all elements of G that commute with a. Definition, example, and how to keep abelian, center, and centralizer definitions straight.
Well done! Made the concepts of center and centralizer very intuitive.
Great !!! Thank you !!!
Centralizer? More like "Cool video; now we're wiser!"
Your explanation was great but I wasn't able to find the link to the dihedral group explorer you used in this video :c
Greetings. As always, thank you for excellent video lectures. Question?: 9:50-9:55
If centralizers are subgroups, as you said they are, then the smallest non trivial centralizer has two elements, e and the second element, provided the second elements is its own inverse. If the element beside e is not its own inverse, then the smallest centralizer should have three elements. Am I correct?
Ali Umar Yes. Since the centralizer of g in G is a subgroup of G, it may have the structure of any known group. So what you say here is a more generally true statement about groups: any group having an element h that is not its own inverse must have at least three elements, namely e, h, and h⁻¹. (By the way, groups in which *every* element is its own inverse are called elementary groups. They're all abelian and have order equal to a power of 2.)
@@MatthewSalomone Thank you Sir. I love each and every single of your lectures. You are an assets to your institution and to your students. They are fortunate to have your live lectures and I am fortunate to learn about your you-tube channel and to take notes of your excellent video lectures. Stay Safe
When you say the centralizer is the largest set of elements that commute I start thinking there are multiple sets and you pick the largest. My thinking is that you are really saying that its the set of all g that commute with a.