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inheritance of module structure

Open eisenbud opened this issue 7 years ago • 2 comments

If phi: S-->R is a ring homomorphism, M is an S-module and N is an R module, then there is an unambiguous structure of R-module on M\otimes N relative to phi.

In many cases, for example when R has been defined as S/I, one can write map(R,S) in M2 without specifying the map -- that is, there is a "natural" choice.

I suggest that in exactly these cases M**N should be defined as an R-module. More generally, I suggest that one allow a syntax like tensor(phi, M, N) to be the R-module as above.

eisenbud avatar Nov 24 '18 16:11 eisenbud

Sounds good to me.

DanGrayson avatar Nov 24 '18 17:11 DanGrayson

Since phi ** M in M2 gives an R-module (here is the documentation), is this the same as phi ** M ** N?

mahrud avatar Jul 06 '20 17:07 mahrud

I believe my last comment means this issue can be closed, but we can reopen it if I'm missing something.

Since phi ** M in M2 gives an R-module (here is the documentation), is this the same as phi ** M ** N?

mahrud avatar Jun 20 '24 20:06 mahrud