When we refer to topology on a metric space $S$ , do we mean the topology generated by open ball?












4














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 ?










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    4














    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 ?










    share|cite|improve this question

























      4












      4








      4







      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 ?










      share|cite|improve this question













      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






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      asked Dec 28 '18 at 3:53









      J.Guo

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          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.






          share|cite|improve this answer































            3














            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 $B(x,r)subset U$.






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              2 Answers
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              7














              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.






              share|cite|improve this answer




























                7














                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.






                share|cite|improve this answer


























                  7












                  7








                  7






                  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.






                  share|cite|improve this answer














                  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.







                  share|cite|improve this answer














                  share|cite|improve this answer



                  share|cite|improve this answer








                  edited 16 hours ago

























                  answered Dec 28 '18 at 4:00









                  Perturbative

                  4,13011450




                  4,13011450























                      3














                      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 $B(x,r)subset U$.






                      share|cite|improve this answer


























                        3














                        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 $B(x,r)subset U$.






                        share|cite|improve this answer
























                          3












                          3








                          3






                          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 $B(x,r)subset U$.






                          share|cite|improve this answer












                          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 $B(x,r)subset U$.







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered Dec 28 '18 at 4:15









                          Chris Custer

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