I read that if we have a topological space $(X,\tau)$, $x\in X$, if we define $C$ as the component of $x$ and $Q$ as the quasicomponents of $x$, we have the well known relations $C\subseteq Q$, so I can consider $Q=Q_1$ with the relative topology and consider $Q_2$ that is the quasicomponent of $x$ in $Q_1$, so $C\subseteq Q_2$, more in general I can define recursively the sets $Q_\alpha$ in this way: $\forall\alpha: Q_{\alpha+1}$ is the quasicomponent of $x$ in $Q_\alpha$, and for the limits ordinals $Q_\alpha=\bigcap_{\beta<\alpha} Q_\beta$. At this point we have $C\subseteq Q_\alpha,\forall\alpha$ and there exist a $\beta$ such that $Q_\beta=Q_{\beta+1}$ for matters of cardinality and, miracuously, we have $C=Q_\beta$. I understood the construction, but i have no idea of why must holds $C=Q_\beta$, can you explain it to me or al least provide me with some reference?
2026-02-22 22:34:53.1771799693
The components are the transfinitely iterated stationary quasicomponents
36 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in GENERAL-TOPOLOGY
- Is every non-locally compact metric space totally disconnected?
- Let X be a topological space and let A be a subset of X
- Continuity, preimage of an open set of $\mathbb R^2$
- Question on minimizing the infimum distance of a point from a non compact set
- Is hedgehog of countable spininess separable space?
- Nonclosed set in $ \mathbb{R}^2 $
- I cannot understand that $\mathfrak{O} := \{\{\}, \{1\}, \{1, 2\}, \{3\}, \{1, 3\}, \{1, 2, 3\}\}$ is a topology on the set $\{1, 2, 3\}$.
- If for every continuous function $\phi$, the function $\phi \circ f$ is continuous, then $f$ is continuous.
- Defining a homotopy on an annulus
- Triangle inequality for metric space where the metric is angles between vectors
Related Questions in CONNECTEDNESS
- Estimation of connected components
- decomposing a graph in connected components
- Proving that we can divide a graph to two graphs which induced subgraph is connected on vertices of each one
- Does every connected topological space have the property that you can walk around a finite open cover to get from any point to any other?
- A set with more than $n$ components has $n+1$ pairwise separated subsets.
- Can connectedness preservation be used to define continuity of a function?
- Prove the set is not connected
- Related the property of two points contained in the same component
- Is a connected component a group?
- f is a continuous function from (X,$\tau$) to {0,1} with discrete topology, if f non constant then (X,$\tau$) disconnected
Related Questions in TRANSFINITE-RECURSION
- Does there exist a weakly increasing cofinal function $\kappa \to \kappa$ strictly below the diagonal?
- The Veblen Hierarchy named with uncountable ordinals vs ordinal collapsing functions
- "Recursively" expressing continuous-time trajectories
- what is the difference between $\aleph_0$ and $ \beth_0$
- The components are the transfinitely iterated stationary quasicomponents
- Contents of Gentzen's consistency proof of PA
- Finding a well-ordering of the natural numbers of a given order type
- How to formally use transfinite recursion to construct a sequence for a proof of Zorn's lemma
- What does a hyperreal version of the Cantor Set look like?
- Applying transfinite recursion
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?
If $Q_\beta$ were disconnected, it would have a nontrivial clopen set and thus would have more than one quasicomponent, so $Q_{\beta+1}$ would be smaller than $Q_\beta$. Since $Q_\beta=Q_{\beta+1}$, that means that $Q_\beta$ is connected.
So $Q_\beta$ is a connected set containing $x$, which means $Q_\beta\subseteq C$. We also have $C\subseteq Q_\alpha$ for all $\alpha$ and in particular for $\alpha=\beta$. Thus $Q_\beta=C$.