When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball?
I've just learned a throrem which states that : A metric space has the structure of a topological space in which the open sets are unions of balls .
But the theorem only told me there "exist" one topology with respect to the metric.When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball ?
general-topology
add a comment |
I've just learned a throrem which states that : A metric space has the structure of a topological space in which the open sets are unions of balls .
But the theorem only told me there "exist" one topology with respect to the metric.When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball ?
general-topology
add a comment |
I've just learned a throrem which states that : A metric space has the structure of a topological space in which the open sets are unions of balls .
But the theorem only told me there "exist" one topology with respect to the metric.When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball ?
general-topology
I've just learned a throrem which states that : A metric space has the structure of a topological space in which the open sets are unions of balls .
But the theorem only told me there "exist" one topology with respect to the metric.When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball ?
general-topology
general-topology
asked Dec 28 '18 at 3:53
J.GuoJ.Guo
2529
2529
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
Yes, a metric space $(S, d)$ induces a topology $mathcal{T}$ which is generated by the basis $$mathcal{B} = {B(x, r) | x in S text{ and } r > 0}$$
When authors refer to the topology on this metric space $(S, d)$, they usually mean the topology $mathcal{T}$ above, which you can think of as the topology generated by open balls.
add a comment |
Yes. So you can say that a set $U$ is open iff for each $xin U$, there exists an open ball $B(x,r)$ centered at $x$ with $B(x,r)subset U$.
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3054558%2fwhen-we-refer-to-topology-on-a-metric-space-s-do-we-mean-the-topology-genera%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Yes, a metric space $(S, d)$ induces a topology $mathcal{T}$ which is generated by the basis $$mathcal{B} = {B(x, r) | x in S text{ and } r > 0}$$
When authors refer to the topology on this metric space $(S, d)$, they usually mean the topology $mathcal{T}$ above, which you can think of as the topology generated by open balls.
add a comment |
Yes, a metric space $(S, d)$ induces a topology $mathcal{T}$ which is generated by the basis $$mathcal{B} = {B(x, r) | x in S text{ and } r > 0}$$
When authors refer to the topology on this metric space $(S, d)$, they usually mean the topology $mathcal{T}$ above, which you can think of as the topology generated by open balls.
add a comment |
Yes, a metric space $(S, d)$ induces a topology $mathcal{T}$ which is generated by the basis $$mathcal{B} = {B(x, r) | x in S text{ and } r > 0}$$
When authors refer to the topology on this metric space $(S, d)$, they usually mean the topology $mathcal{T}$ above, which you can think of as the topology generated by open balls.
Yes, a metric space $(S, d)$ induces a topology $mathcal{T}$ which is generated by the basis $$mathcal{B} = {B(x, r) | x in S text{ and } r > 0}$$
When authors refer to the topology on this metric space $(S, d)$, they usually mean the topology $mathcal{T}$ above, which you can think of as the topology generated by open balls.
edited Jan 4 at 6:54
answered Dec 28 '18 at 4:00
PerturbativePerturbative
4,14011450
4,14011450
add a comment |
add a comment |
Yes. So you can say that a set $U$ is open iff for each $xin U$, there exists an open ball $B(x,r)$ centered at $x$ with $B(x,r)subset U$.
add a comment |
Yes. So you can say that a set $U$ is open iff for each $xin U$, there exists an open ball $B(x,r)$ centered at $x$ with $B(x,r)subset U$.
add a comment |
Yes. So you can say that a set $U$ is open iff for each $xin U$, there exists an open ball $B(x,r)$ centered at $x$ with $B(x,r)subset U$.
Yes. So you can say that a set $U$ is open iff for each $xin U$, there exists an open ball $B(x,r)$ centered at $x$ with $B(x,r)subset U$.
answered Dec 28 '18 at 4:15
Chris CusterChris Custer
10.9k3824
10.9k3824
add a comment |
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3054558%2fwhen-we-refer-to-topology-on-a-metric-space-s-do-we-mean-the-topology-genera%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown