Given a Lebesgue measurable subset $E \subset \mathbb{R}^N$ we denote its $N-$dimensional Lebesgue measure by $|E|$. Let $\Omega \subset \mathbb{R}^N$ a bounded measurable set and $u : \Omega \to \mathbb{R}$ be a measurable function. For $t \in \mathbb{R}$ we define $$ \{ u > t\} = \{x \in \Omega : u(x) > t\}. $$ The distribution function of $u$ is given by $$ \mu_u(t) = |\{u > t\}|. $$ The (uni dimensional) decreasing rearrangement of $u$ is defined on $[0, |\Omega|]$ by \begin{equation} u^{\#}(s) = \left\{ \begin{array}{rcll} \text{ess sup} (u),& \text{ if }s = 0 \\ \inf\{t : \mu_u(t) < s\} ,& \text{ if } 0 < s < |\Omega| \end{array}, \right. \end{equation} Given $E \subset \mathbb{R}^N$ a measurable set of finite measure. We define $E^\ast$, the symmetric rearrangement of $E$ to be $$ B_R(0), R = \left(\frac{|E|}{|B|}\right)^{\frac{1}{N}}. $$ Notice that $|E| = |E^\ast|$. Let $\Omega \subset \mathbb{R}^N$ be a bounded domain and Let $u : \Omega \to \mathbb{R}$ be a measurable function. Its Schwarz symmetrization or, the spherically symmetric and decreasing rearrangement is the function $u^\ast : \Omega^\ast \to \mathbb{R}$ defined by $$ u^\ast (x) = u^{\#}(|B||x|^N), \quad x \in \Omega^{\ast}. $$ I would like to know if is it possible to define Schwarz rearrangment with other kind of symmetriztion intead of a ball, for example, taking $E^{\ast}$ is a annulos with the same measure as $E$, in such a way that all the properties are preserved.
2026-02-23 17:19:33.1771867173
Defining Schwars rearrangement for other kind of symmetric domains
7 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in MEASURE-THEORY
- On sufficient condition for pre-compactness "in measure"(i.e. in Young measure space)
- Absolutely continuous functions are dense in $L^1$
- I can't undestand why $ \{x \in X : f(x) > g(x) \} = \bigcup_{r \in \mathbb{Q}}{\{x\in X : f(x) > r\}\cap\{x\in X:g(x) < r\}} $
- Trace $\sigma$-algebra of a product $\sigma$-algebra is product $\sigma$-algebra of the trace $\sigma$-algebras
- Meaning of a double integral
- Random variables coincide
- Convergence in measure preserves measurability
- Convergence in distribution of a discretized random variable and generated sigma-algebras
- A sequence of absolutely continuous functions whose derivatives converge to $0$ a.e
- $f\in L_{p_1}\cap L_{p_2}$ implies $f\in L_{p}$ for all $p\in (p_1,p_2)$
Related Questions in SYMMETRY
- Do projective transforms preserve circle centres?
- Decomposing an arbitrary rank tensor into components with symmetries
- A closed manifold of negative Ricci curvature has no conformal vector fields
- Show, by means of an example, that the group of symmetries of a subset X of a Euclidean space is, in general, smaller than Sym(x).
- How many solutions are there if you draw 14 Crosses in a 6x6 Grid?
- Symmetry of the tetrahedron as a subgroup of the cube
- Number of unique integer coordinate points in an $n$- dimensional hyperbolic-edged tetrahedron
- The stretch factors of $A^T A$ are the eigenvalues of $A^T A$
- The square root of a positive semidefinite matrix
- Every conformal vector field on $\mathbb{R}^n$ is homothetic?
Related Questions in SYMMETRIC-FUNCTIONS
- Is this symmetric rational function known?
- Name for the relationship $f\left(\frac{1}{x}\right) = \sqrt{x}f(x)$
- Proving an identity for complete homogenous symmetric polynomials
- Solve $x+\frac{1}{y-x}=1$, $y+\frac{1}{x-y}=2$
- Find distinct real numbers satisfying $\frac{xy}{x-y} = \frac{1}{30}$ and $\frac{x^2y^2}{x^2+y^2} = \frac{1}{2018}$
- The Uniqueness of Symmetrization of functions
- Trivial induced representation and the Frobenius Character
- Symmetric function of the roots is a rational function of the coefficients.
- positivity in bases of symmetric functions
- reference request: Type A crystal proof of Schur-positivity
Related Questions in DECREASING-REARRANGEMENTS
- Nonnegativity assumption for the Schwarz rearrangement of a function
- Schwarz symmetrization is equimeasurable
- symmetrized rearrangement on sphere.
- Distribution function and decreasing rearrangement
- Spherical rearrangement
- The graph of symmetric-decreasing rearrangment of some function eg. $e^{x}$
- Isoperimetric inequality with Green-capacitiy
- Does the symmetric decreasing rearrangement of a smooth function preserve smoothness?
- On rearrangement of level set: $\{f>t\}^* = \{f^*>t\}\,\,\text{?}$
- Rearrangement of Laplacian function
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?