okay, since you've completely degraded yourself to childish insults. I'll leave you at that. I was hoping you would jump into the fray cause you've confessed to a phd degree in math.
And I was trying to be civil all throughout. I like this place. It really tests my patience on civility.
Do you know what a module is? Don't answer that, if you knew what a module is, the case I was referring to should have been clear as day. But I'll humor the ignorance and illustrate the case.
I was hoping you would jump into the fray cause you've confessed to a phd degree in math.
but does not have a Ph. D.. I, on the other hand, do.
What in, may one ask, and from where?
Let R be a ring. Let A be an additive abelian group.
Consider A as a (left) R-module(ok, are we fine with this?)
3, 2 \in R and x \in A. Let R and A be disjoint, such that \forall r \in R, r\notin A and \forall a \in A a\notin R.
consider 3x + 2 again.
There is not such thing as an "additive abelian group." Every abelian group can be written additively. That is how I will interpret your post from here on: $A$ is an arbitrary abelian group, written additively.No. If you proceed with this wording, you will get nowhere. You mean, "let $R$ act on $A$ from the left." $A$ is not the module.How a mathematician would write this: $2, 3 \in R, x \in A, R \cap A = \varnothing$.I assume you mean in the module. Ok, what about it?$1\notin R, \sigma(x) = 2; \forall r \in R, a \in A s.t. a \neq x, ra = 0. 3 \in R, 3x = 3x + 2; \forall r \in R s.t. r\neq 3, rx = 0$.There is a module where 3x + 2 is defined, despite your stipulations.
3x + 2 will, in general, not be defined in such a module
Finally a proper response I'm glad to read. I presented a case where 3x+2 isn't in the module but you gave an example where 3x+2 is defined despite my stipulations. That's acceptable. If you did that from the get go then none of the previous altercations were necessary.
You did not present such a case; you were not specific enough. I can abuse your notation easily. In general, 3x + 2 will not be defined in that module. However, it was not the ultimate assertion that I objected to; you made many other statements in the post that I initially responded to. Those are the statements which are bizarre.Edit: btw, in your quote, which you apparently made between my edits, what is described is not actually a module. I need 2 to be the additive identity of R, something I left off in the first version.
PS: I wish I had taken group theory as an undergrad. It sounds like a lot of fun.
In mathematics, from UAB, as of three weeks from now. My research is in group theory, algebraic geometry, algebraic combinatorics and automorphic forms.
Basic group theory is moderately self-teachable, although you may get hung up on a couple of things, as nearly all students do (specifically quotient groups, Sylow's Theorems, normal series, central series, the Frattini subgroup and commutator subgroups). Group theory can be studied to an extremely high level in a pretty self-contained manner (even up into current research areas), without venturing out into other areas of upper level mathematics. As of right now, the main areas of research in group theory are:Thin groups, which only requires a basic knowledge of graph theory,discrete groups and abstract harmonic analysis (via automorphic forms: not approachable),lie representations (approachable if you're willing to beef up on linear + multilinear algebra),p-adic representations (not approachable; requires a lot of number theory),classical invariant theory (not approachable: requires a lot of combinatorics),and fusion systems (self-contained, but very high level).Computational group theory using GAP (a computer program) is also popular atm, but what exactly they're doing I'm not sure. It's not relevant to automorphic forms or fusion systems, which is what I study in the context of group theory. For the most part, they're just compiling absolutely as much info as possible on groups of small and medium order (say, under 1000 elements).I can send you a PDF of Dummit-Foote, the standard intro text, if you think you're interested.
Please send me the pdf! I'd love to take a look. My email id is impromptu.pianist AT gmail.comThanks.