Talk:Torsion (algebra)/Archive 1

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Archive 1

Example 1

example 1 is wrong - take Z/8 as a free Z/8-module. Then the module generated by the element 2 has a nonzero annihilator. 69.203.194.3 22:39, 18 September 2007 (UTC)

Thanks! Torsion only behaves well over domains (which was reflected in the definition in the article), I've corrected the example accordingly. Arcfrk 00:37, 19 September 2007 (UTC)

On a closer look, for a general ring (not a domain), the definition of torsion is modified so that only non-zero divisors matter (last paragraph of the definition). So this is not a counterexample (4 annihilates the submodule (2), but 4 is not invertible in the ring). In fact, the statement as given was correct. Arcfrk 03:39, 20 September 2007 (UTC)

Unfocused?

This article feels unfocused. Shouldn't this be turned into a disambig page or something? A torsion module is important enough for its article. So are torsion points in abelian varieties. -- Taku (talk) 00:58, 30 January 2013 (UTC)

Yeah, "torsion" is pretty vague. When I think of torsion, the things that come to mind is the torsion submodule, and torsion theories, which are rather advanced theories of noncommutative localization. Rschwieb (talk) 21:02, 30 January 2013 (UTC)