Balanced Word to Balanced (Sturmian?) Sequence












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Let $E in {0,1}^{n}, nin mathbb{N}$, be a balanced finite word: for every two subwords $U,V$ of the same length, the number of $1$'s in $U$ differs from the number of $1$'s in $V$ by at most one.




  • Can $E$ be continued to an infinite balanced sequence?

  • Can $E$ be continued to an infinite Sturmian sequence? (A subcase of the previous question.)


Furthermore, in both cases, what is the cardinality of the set of possible extensions of $E$?



This came up when I tried to solve an exercise, where I have to show that Sturmian sequences are dense in the space of balanced sequences (with regard to the usual topology of symbolic dynamics) - if the the answer to the second question is "yes", than we can take any prefix of length $n$ of a balanced sequence, continue it to a Sturmian sequence, and get by the definition of the metric that the distance between the two sequences is $leq frac{1}{2^n}$.










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    $begingroup$


    Let $E in {0,1}^{n}, nin mathbb{N}$, be a balanced finite word: for every two subwords $U,V$ of the same length, the number of $1$'s in $U$ differs from the number of $1$'s in $V$ by at most one.




    • Can $E$ be continued to an infinite balanced sequence?

    • Can $E$ be continued to an infinite Sturmian sequence? (A subcase of the previous question.)


    Furthermore, in both cases, what is the cardinality of the set of possible extensions of $E$?



    This came up when I tried to solve an exercise, where I have to show that Sturmian sequences are dense in the space of balanced sequences (with regard to the usual topology of symbolic dynamics) - if the the answer to the second question is "yes", than we can take any prefix of length $n$ of a balanced sequence, continue it to a Sturmian sequence, and get by the definition of the metric that the distance between the two sequences is $leq frac{1}{2^n}$.










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Let $E in {0,1}^{n}, nin mathbb{N}$, be a balanced finite word: for every two subwords $U,V$ of the same length, the number of $1$'s in $U$ differs from the number of $1$'s in $V$ by at most one.




      • Can $E$ be continued to an infinite balanced sequence?

      • Can $E$ be continued to an infinite Sturmian sequence? (A subcase of the previous question.)


      Furthermore, in both cases, what is the cardinality of the set of possible extensions of $E$?



      This came up when I tried to solve an exercise, where I have to show that Sturmian sequences are dense in the space of balanced sequences (with regard to the usual topology of symbolic dynamics) - if the the answer to the second question is "yes", than we can take any prefix of length $n$ of a balanced sequence, continue it to a Sturmian sequence, and get by the definition of the metric that the distance between the two sequences is $leq frac{1}{2^n}$.










      share|cite|improve this question











      $endgroup$




      Let $E in {0,1}^{n}, nin mathbb{N}$, be a balanced finite word: for every two subwords $U,V$ of the same length, the number of $1$'s in $U$ differs from the number of $1$'s in $V$ by at most one.




      • Can $E$ be continued to an infinite balanced sequence?

      • Can $E$ be continued to an infinite Sturmian sequence? (A subcase of the previous question.)


      Furthermore, in both cases, what is the cardinality of the set of possible extensions of $E$?



      This came up when I tried to solve an exercise, where I have to show that Sturmian sequences are dense in the space of balanced sequences (with regard to the usual topology of symbolic dynamics) - if the the answer to the second question is "yes", than we can take any prefix of length $n$ of a balanced sequence, continue it to a Sturmian sequence, and get by the definition of the metric that the distance between the two sequences is $leq frac{1}{2^n}$.







      general-topology dynamical-systems combinatorics-on-words






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      edited Dec 8 '18 at 9:45







      co.sine

















      asked Dec 6 '18 at 8:30









      co.sineco.sine

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