nonuniform local ring with essential socle
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I need an example: Is there any local non uniform ring $R$ with essential socle and its socle is exactly direct sum of ALL minimal left ideals? Thanks.
abstract-algebra ring-theory modules
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I need an example: Is there any local non uniform ring $R$ with essential socle and its socle is exactly direct sum of ALL minimal left ideals? Thanks.
abstract-algebra ring-theory modules
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up vote
1
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favorite
up vote
1
down vote
favorite
I need an example: Is there any local non uniform ring $R$ with essential socle and its socle is exactly direct sum of ALL minimal left ideals? Thanks.
abstract-algebra ring-theory modules
I need an example: Is there any local non uniform ring $R$ with essential socle and its socle is exactly direct sum of ALL minimal left ideals? Thanks.
abstract-algebra ring-theory modules
abstract-algebra ring-theory modules
asked 2 days ago
Algebra.m
162
162
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There is no such example.
That is, let $R$ be a local ring with essential left socle which is the direct sum of all minimal left ideals.
Since $R$ is local, all the minimal left ideals of $R$ are isomorphic to $R/M$ where $M$ is the maximal ideal.
Suppose $phi :L_1to L_2$ is an isomorphism of two such minimal left ideals. Then necessarily $L_1oplus L_2$ is contained in the socle. But ${x+phi(x)mid xin L_1}$ is another left ideal of $R$ which is easily seen to be isomorphic to $L_1$ and $L_2$. Including this copy of $L_1$ in the sum would make it fail to be a direct sum.
So, the left socle is necessarily just one minimal left ideal. Since you have also assumed it is essential, it is in fact contained in every other left ideal, making the ring left uniform.
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1 Answer
1
active
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
There is no such example.
That is, let $R$ be a local ring with essential left socle which is the direct sum of all minimal left ideals.
Since $R$ is local, all the minimal left ideals of $R$ are isomorphic to $R/M$ where $M$ is the maximal ideal.
Suppose $phi :L_1to L_2$ is an isomorphism of two such minimal left ideals. Then necessarily $L_1oplus L_2$ is contained in the socle. But ${x+phi(x)mid xin L_1}$ is another left ideal of $R$ which is easily seen to be isomorphic to $L_1$ and $L_2$. Including this copy of $L_1$ in the sum would make it fail to be a direct sum.
So, the left socle is necessarily just one minimal left ideal. Since you have also assumed it is essential, it is in fact contained in every other left ideal, making the ring left uniform.
add a comment |
up vote
0
down vote
There is no such example.
That is, let $R$ be a local ring with essential left socle which is the direct sum of all minimal left ideals.
Since $R$ is local, all the minimal left ideals of $R$ are isomorphic to $R/M$ where $M$ is the maximal ideal.
Suppose $phi :L_1to L_2$ is an isomorphism of two such minimal left ideals. Then necessarily $L_1oplus L_2$ is contained in the socle. But ${x+phi(x)mid xin L_1}$ is another left ideal of $R$ which is easily seen to be isomorphic to $L_1$ and $L_2$. Including this copy of $L_1$ in the sum would make it fail to be a direct sum.
So, the left socle is necessarily just one minimal left ideal. Since you have also assumed it is essential, it is in fact contained in every other left ideal, making the ring left uniform.
add a comment |
up vote
0
down vote
up vote
0
down vote
There is no such example.
That is, let $R$ be a local ring with essential left socle which is the direct sum of all minimal left ideals.
Since $R$ is local, all the minimal left ideals of $R$ are isomorphic to $R/M$ where $M$ is the maximal ideal.
Suppose $phi :L_1to L_2$ is an isomorphism of two such minimal left ideals. Then necessarily $L_1oplus L_2$ is contained in the socle. But ${x+phi(x)mid xin L_1}$ is another left ideal of $R$ which is easily seen to be isomorphic to $L_1$ and $L_2$. Including this copy of $L_1$ in the sum would make it fail to be a direct sum.
So, the left socle is necessarily just one minimal left ideal. Since you have also assumed it is essential, it is in fact contained in every other left ideal, making the ring left uniform.
There is no such example.
That is, let $R$ be a local ring with essential left socle which is the direct sum of all minimal left ideals.
Since $R$ is local, all the minimal left ideals of $R$ are isomorphic to $R/M$ where $M$ is the maximal ideal.
Suppose $phi :L_1to L_2$ is an isomorphism of two such minimal left ideals. Then necessarily $L_1oplus L_2$ is contained in the socle. But ${x+phi(x)mid xin L_1}$ is another left ideal of $R$ which is easily seen to be isomorphic to $L_1$ and $L_2$. Including this copy of $L_1$ in the sum would make it fail to be a direct sum.
So, the left socle is necessarily just one minimal left ideal. Since you have also assumed it is essential, it is in fact contained in every other left ideal, making the ring left uniform.
answered 2 days ago
rschwieb
103k1299238
103k1299238
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