Talk:Conjugacy class

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Mathematics rating:	B Class	High Priority	Field: Algebra
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. References, links etc. would help. Geometry guy 14:31, 21 May 2007 (UTC)

Reverting to previous text , as the centralizer is indeed a subgroup of G; if a,b in C_G(g), then:

• C_G is not empty, since (g*g)*g = g*(g*g).
• b * g = g * b → b ^-1 * g = g * b ^-1; thus b ^-1 is in C_G(g)
• (a*b ^-1)*g = a*(b ^-1*g) = a*(g*b ^-1) = (a*g)*b ^-1 = (g*a)*b ^-1 = g*(a*b ^-1) → a*b ^-1 in C_G(g).

thus by elementary group theory, C_G(g) is a subgroup of G.

It is true that C_G(g) is not a normal subgroup of G; but that's not what was stated in the article. Maybe this should be added to the article.User:chas_zzz_brown