One inequality is obvious, but the other one im not sure if holds. Any idea?
2026-03-31 17:54:19.1774979659
$IJ =(I\cap J)(I+J)$ holds in a PID? $I,J$ Ideals of a PID
144 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in ABSTRACT-ALGEBRA
- Feel lost in the scheme of the reducibility of polynomials over $\Bbb Z$ or $\Bbb Q$
- Integral Domain and Degree of Polynomials in $R[X]$
- Fixed points of automorphisms of $\mathbb{Q}(\zeta)$
- Group with order $pq$ has subgroups of order $p$ and $q$
- A commutative ring is prime if and only if it is a domain.
- Conjugacy class formula
- Find gcd and invertible elements of a ring.
- Extending a linear action to monomials of higher degree
- polynomial remainder theorem proof, is it legit?
- $(2,1+\sqrt{-5}) \not \cong \mathbb{Z}[\sqrt{-5}]$ as $\mathbb{Z}[\sqrt{-5}]$-module
Related Questions in RING-THEORY
- Jacobson radical = nilradical iff every open set of $\text{Spec}A$ contains a closed point.
- A commutative ring is prime if and only if it is a domain.
- Find gcd and invertible elements of a ring.
- Prove that $R[x]$ is an integral domain if and only if $R$ is an integral domain.
- Prove that $Z[i]/(5)$ is not a field. Check proof?
- If $P$ is a prime ideal of $R[x;\delta]$ such as $P\cap R=\{0\}$, is $P(Q[x;\delta])$ also prime?
- Let $R$ be a simple ring having a minimal left ideal $L$. Then every simple $R$-module is isomorphic to $L$.
- A quotient of a polynomial ring
- Does a ring isomorphism between two $F$-algebras must be a $F$-linear transformation
- Prove that a ring of fractions is a local ring
Related Questions in IDEALS
- Prime Ideals in Subrings
- Ideals of $k[[x,y]]$
- Product of Ideals?
- Let $L$ be a left ideal of a ring R such that $ RL \neq 0$. Then $L$ is simple as an R-module if and only if $L$ is a minimal left ideal?
- Show $\varphi:R/I\to R/J$ is a well-defined ring homomorphism
- A question on the group algebra
- The radical of the algebra $ A = T_n(F)$ is $N$, the set of all strictly upper triangular matrices.
- Prove that $\langle 2,1+\sqrt{-5} \rangle ^ 2 \subseteq \langle 2 \rangle$
- $\mathbb{Z}[i] / (2+3i)$ has 13 elements
- Ideal $I_p$ in $\mathbb{F}_l[x]/(x^p -1)$ where $\frac{\epsilon p}{2} \leq \dim(I_p) < \epsilon p$
Related Questions in PRINCIPAL-IDEAL-DOMAINS
- Principal Ideal Ring which is not Integral
- A variation of the argument to prove that $\{m/n:n \text{ is odd },n,m \in \mathbb{Z}\}$ is a PID
- Why is this element irreducible?
- Quotient of normal ring by principal ideal
- $R/(a) \oplus R/(b) \cong R/\gcd(a,b) \oplus R/\operatorname{lcm}(a,b) $
- Proving a prime ideal is maximal in a PID
- Localization of PID, if DVR, is a localization at a prime ideal
- Structure theorem for modules implies Smith Normal Form
- Let R be a PID, B a torsion R module and p a prime in R. Prove that if $pb=0$ for some non zero b in B, then $\text{Ann}(B)$ is a subset of (p)
- Why can't a finitely generated module over a PID be generated by fewer elements than the number of invariant factors?
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?
Let's take $I=(a)$ and $J=(b)$. Then $IJ=(ab)$. $I\cap J= (\operatorname{lcm}(a,b))$ and $I+J=(\operatorname{gcd}(a,b))$. The fact that lcm and gcd exist is due to the fact that we're working in a UFD. Therefore $(I\cap J)(I+J)=(\operatorname{lcm}(a,b)\cdot\operatorname{gcd}(a,b))=(ab)$. This holds generally for principal ideals in a UFD, but since every ideal in a PID is principal, it holds for all ideals $I,J$.