Tensor product of short exact sequences

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Let $k$ be a field and $R=k[x_j:jin J]/I$ be a smooth $k$-Algebra. Then $R otimes R$ is also a smooth $k$-Algebra and by the universal property of the tensor product, we obtain a (surjective) map $k[x_i:iin J] otimes k[x_j :jin J] rightarrow Rotimes R$.



Can we say anything about the kernel? If yes, how Is it related to $I otimes k[x_j :jin J] +k[x_j:iin J] otimes I$?







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    The kernel should look more like $Iotimes 1+1otimes I$.
    – Pedro Tamaroff♦
    Aug 27 at 12:30










  • Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
    – slinshady
    Aug 27 at 12:43














up vote
1
down vote

favorite












Let $k$ be a field and $R=k[x_j:jin J]/I$ be a smooth $k$-Algebra. Then $R otimes R$ is also a smooth $k$-Algebra and by the universal property of the tensor product, we obtain a (surjective) map $k[x_i:iin J] otimes k[x_j :jin J] rightarrow Rotimes R$.



Can we say anything about the kernel? If yes, how Is it related to $I otimes k[x_j :jin J] +k[x_j:iin J] otimes I$?







share|cite|improve this question


















  • 1




    The kernel should look more like $Iotimes 1+1otimes I$.
    – Pedro Tamaroff♦
    Aug 27 at 12:30










  • Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
    – slinshady
    Aug 27 at 12:43












up vote
1
down vote

favorite









up vote
1
down vote

favorite











Let $k$ be a field and $R=k[x_j:jin J]/I$ be a smooth $k$-Algebra. Then $R otimes R$ is also a smooth $k$-Algebra and by the universal property of the tensor product, we obtain a (surjective) map $k[x_i:iin J] otimes k[x_j :jin J] rightarrow Rotimes R$.



Can we say anything about the kernel? If yes, how Is it related to $I otimes k[x_j :jin J] +k[x_j:iin J] otimes I$?







share|cite|improve this question














Let $k$ be a field and $R=k[x_j:jin J]/I$ be a smooth $k$-Algebra. Then $R otimes R$ is also a smooth $k$-Algebra and by the universal property of the tensor product, we obtain a (surjective) map $k[x_i:iin J] otimes k[x_j :jin J] rightarrow Rotimes R$.



Can we say anything about the kernel? If yes, how Is it related to $I otimes k[x_j :jin J] +k[x_j:iin J] otimes I$?









share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Aug 27 at 13:58

























asked Aug 27 at 12:06









slinshady

355110




355110







  • 1




    The kernel should look more like $Iotimes 1+1otimes I$.
    – Pedro Tamaroff♦
    Aug 27 at 12:30










  • Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
    – slinshady
    Aug 27 at 12:43












  • 1




    The kernel should look more like $Iotimes 1+1otimes I$.
    – Pedro Tamaroff♦
    Aug 27 at 12:30










  • Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
    – slinshady
    Aug 27 at 12:43







1




1




The kernel should look more like $Iotimes 1+1otimes I$.
– Pedro Tamaroff♦
Aug 27 at 12:30




The kernel should look more like $Iotimes 1+1otimes I$.
– Pedro Tamaroff♦
Aug 27 at 12:30












Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
– slinshady
Aug 27 at 12:43




Indeed you are right. This is also what I wanted to express, that was a bit careless off me.
– slinshady
Aug 27 at 12:43















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