Questions tagged [noetherian]

For questions on Noetherian rings, Noetherian modules and related notions.

554 questions
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Every ideal contains a power of it's radical in a Noetherian ring.

Let $I$ be an ideal in a Noetherian ring $R$. Prove that there exists a positive integer $N$ such that $\text{rad}(I)^N ⊂ I$. [Hint:Let $\text{rad}(I)=⟨g_1,\ldots,g_k⟩$,and suppose $g_i^{n_i} \in I$....
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Converse of : If $M$ is Noetherian then $M_m$ is Noetherian for every $m\in\operatorname{Max}(R)$.

Let $R$ be a Noetherian ring and $M$ be an $R$-module. We know that if $M$ is Noetherian then $M_m$ is a Noetherian $R_m$-module for every $m\in\operatorname{Max}(R)$. Now, I want to know if the ...
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Primary decomposition of modules - uniqueness proof

Let $M$ be $A$-module, $A$ commutative ring, and $N$ submodule and let $$N=Q_1\cap\dots\cap Q_r=Q'_1\cap \dots \cap Q'_s$$ be reduced primary decompositions of $N$. Then $r=s$. The set of primes ...
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Let $(A, +, \cdot )$ be a ring such that $A/<x>$ is finite, for every $0 \neq x \in A$. Show that $A$ is noetherian.

I tried to show that every ideal $I$ of $A$ is finite. Let $0 \neq x \in I$. By hypothesis there is $x_1, x_2, ..., x_k \in A$ such that $$A/<x> = <x_1+<x>,..., x_k+<x>>$$ I ...
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Example of a Noetherian local ring of dimension one which is not a discrete valuation ring. [closed]

What is the example of a Noetherian local ring of dimension one which is not a discrete valuation ring.
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Commutative Noetherian ring with distinct ideals having distinct index

Let $R$ be a Noetherian commutative, infinite ring with unity such that distinct ideals have distinct index i.e. if $I,J$ are ideals of $R$ and $I \ne J$ , then $R/I$ and $R/J$ are not bijective as ...
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Noetherian local ring is Artinian iff maximal ideal is nilpotent

I am browsing through some old lecture notes, and I am trying to prove the following: Let $A$ be a Noetherian local ring with maximal ideal $\mathfrak m$. Show that the following are equivalent: ...
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Noetherian module does not contain a submodule $N$ which is a direct sum of $n$ simple modules

The question: Let $R$ be a ring and $M$ be a Noetherian module. Prove there is $k \in \mathbb{N}$ such for all $n > k$, $M$ does not contain a submodule $N$ which is a direct sum of $n$ simple ...
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Noetherian ring with infinite Krull dimension (Nagata's example).

I just started to read about the Krull dimension (definition and basic theory), at first when I thought about the Krull dimension of a noetherian ring my idea was that it must be finite, however this ...
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Non-Noetherian Domain Which is Locally Noetherian

Let $R$ be an integral domain such that the localization, $R_{\mathfrak p}$, at each prime ideal, $\mathfrak p \le R$ is Noetherian. Then is $R$ necessarily Noetherian? In the case of $R$ not ...
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Ring of Laurent Polynomials is Noetherian Implies Polynomial Ring is Noetherian?

Suppose $R[t, t^{-1}]$ is Noetherian. Is $R[t]$ necessarily Noetherian? (Here, $R$ is a commutative ring with an identity.) I am able to show that the converse is true, but am a bit stuck with this ...
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If $R$ is a right-Noetherian ring and the Jacobson radical satisfies the right Artin-Rees property, then $\bigcap^{\infty}_{n=1}\text{Jac}(R)^n = 0$

A (two-sided) ideal $I$ of a ring with identity $R$ has the right Artin-Rees property if for any right-ideal $E$ of $R$, there exists an integer $n\geq1$ such that $E\cap I^n\subseteq EI$. If $R$ ...
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Hartshorne Exercise III 3.2: $X$ is affine iff every component is affine

I'm trying to solve the following exercise frome Hartshorne's Algebraic Geometry: Exercise III 3.2. Let $X$ be a reduced noetherian scheme. Show that $X$ is affine if and only if each irreducible ...
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In a commutative local Noetherian ring $R$ with maximal ideal $J$, if $J$ is not nilpotent then $R$ is an integral domain.

We've just proved this result: Let $R$ be a commutative, local, Noetherian ring. Suppose that $J$ (the maximal ideal) is principal. Then every nonzero ideal of $R$ is a power of $J$. And now we ...
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Why noetherian ring satisfies the maximal condition?

"maximal condition" means if any non-empty collection of ideals in R has a maximal element (under set inclusion). And we define noetherian ring to be a ring such that any ascending chain of ideals is ...
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On finiteness of $\cup_{n\ge 1 } \operatorname{Ass}_R (R/I^n)$

Let $I$ be an ideal of a commutative noetherian ring $R$. How to prove that $\bigcup_{n\ge 1 }\operatorname{Ass}_R (R/I^n)$ is finite ? I am aware of Brodmann's result about Asymptotic stability ...
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Show that any non-zero prime ideal of $R$ is invertible.

Theorem $:$ Let $R$ be an integral domain such that $R$ is Noetherian, integrally closed and every non-zero prime ideal of $R$ is maximal with quotient field $K.$ Then every non-zero prime ...
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In an integrally closed, Noetherian, local, integral domain of dimension $1$, the maximal ideal $P$ is eventually principal

Let $R$ be an integrally closed, Noetherian, local, integral domain of dimension 1 with unique maximal ideal $P$. Take an element $a \in P$ that is non zero. Show that for some $n$, $P^n$ is ...
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If $R$ is a Noetherian ring then $R[[x]]$ is also Noetherian
Let $R$ be a Noetherian ring. How can one prove that the ring of the formal power series $R[[x]]$ is again a Noetherian ring? It is well-known that the ring of polynomials $R[x]$ is Noetherian. I ...