On the definition of k-simplex

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite












Usually, a $k$-simplex is defined as a subset of $mathbbR^n$ spanned by $k+1$ vertices $v_0,ldots , v_k$, that is the set of linear combinations of the vertices with real non negative coefficients whose sum is $1$. I have two questions: is it possible to substitute $mathbbR^n$ with any real vector space? Has that vector space to be necessarily finite dimensional over $mathbbR$?







share|cite|improve this question
























    up vote
    1
    down vote

    favorite












    Usually, a $k$-simplex is defined as a subset of $mathbbR^n$ spanned by $k+1$ vertices $v_0,ldots , v_k$, that is the set of linear combinations of the vertices with real non negative coefficients whose sum is $1$. I have two questions: is it possible to substitute $mathbbR^n$ with any real vector space? Has that vector space to be necessarily finite dimensional over $mathbbR$?







    share|cite|improve this question






















      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      Usually, a $k$-simplex is defined as a subset of $mathbbR^n$ spanned by $k+1$ vertices $v_0,ldots , v_k$, that is the set of linear combinations of the vertices with real non negative coefficients whose sum is $1$. I have two questions: is it possible to substitute $mathbbR^n$ with any real vector space? Has that vector space to be necessarily finite dimensional over $mathbbR$?







      share|cite|improve this question












      Usually, a $k$-simplex is defined as a subset of $mathbbR^n$ spanned by $k+1$ vertices $v_0,ldots , v_k$, that is the set of linear combinations of the vertices with real non negative coefficients whose sum is $1$. I have two questions: is it possible to substitute $mathbbR^n$ with any real vector space? Has that vector space to be necessarily finite dimensional over $mathbbR$?









      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Aug 14 at 7:26









      bateman

      1,800919




      1,800919




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          1
          down vote



          accepted










          Nothing in the definition of simplex stops you from defining a $k$-simplplex in an infinite dimensional vector space, so the answer to your second question is 'no the vector space does not need to be finite-dimensional'.



          As for the first question, as long as you are able to form finite linear combinations you can form a simplex, albeit if you find yourself dealing with a vector space without an inner product, you may have a hard time verifying whether or not the $v_0,ldots,v_k$ are in general position.






          share|cite|improve this answer




















          • Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
            – bateman
            Aug 14 at 8:06










          • Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
            – John C
            Aug 14 at 12:28










          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',
          convertImagesToLinks: true,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );








           

          draft saved


          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2882164%2fon-the-definition-of-k-simplex%23new-answer', 'question_page');

          );

          Post as a guest






























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          1
          down vote



          accepted










          Nothing in the definition of simplex stops you from defining a $k$-simplplex in an infinite dimensional vector space, so the answer to your second question is 'no the vector space does not need to be finite-dimensional'.



          As for the first question, as long as you are able to form finite linear combinations you can form a simplex, albeit if you find yourself dealing with a vector space without an inner product, you may have a hard time verifying whether or not the $v_0,ldots,v_k$ are in general position.






          share|cite|improve this answer




















          • Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
            – bateman
            Aug 14 at 8:06










          • Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
            – John C
            Aug 14 at 12:28














          up vote
          1
          down vote



          accepted










          Nothing in the definition of simplex stops you from defining a $k$-simplplex in an infinite dimensional vector space, so the answer to your second question is 'no the vector space does not need to be finite-dimensional'.



          As for the first question, as long as you are able to form finite linear combinations you can form a simplex, albeit if you find yourself dealing with a vector space without an inner product, you may have a hard time verifying whether or not the $v_0,ldots,v_k$ are in general position.






          share|cite|improve this answer




















          • Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
            – bateman
            Aug 14 at 8:06










          • Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
            – John C
            Aug 14 at 12:28












          up vote
          1
          down vote



          accepted







          up vote
          1
          down vote



          accepted






          Nothing in the definition of simplex stops you from defining a $k$-simplplex in an infinite dimensional vector space, so the answer to your second question is 'no the vector space does not need to be finite-dimensional'.



          As for the first question, as long as you are able to form finite linear combinations you can form a simplex, albeit if you find yourself dealing with a vector space without an inner product, you may have a hard time verifying whether or not the $v_0,ldots,v_k$ are in general position.






          share|cite|improve this answer












          Nothing in the definition of simplex stops you from defining a $k$-simplplex in an infinite dimensional vector space, so the answer to your second question is 'no the vector space does not need to be finite-dimensional'.



          As for the first question, as long as you are able to form finite linear combinations you can form a simplex, albeit if you find yourself dealing with a vector space without an inner product, you may have a hard time verifying whether or not the $v_0,ldots,v_k$ are in general position.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Aug 14 at 8:01









          John C

          786311




          786311











          • Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
            – bateman
            Aug 14 at 8:06










          • Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
            – John C
            Aug 14 at 12:28
















          • Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
            – bateman
            Aug 14 at 8:06










          • Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
            – John C
            Aug 14 at 12:28















          Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
          – bateman
          Aug 14 at 8:06




          Thank you for your answer. I have a little remark: why do the inner product is necessary? Suppose there is not an inner product. Can I just say the vertices are in general position if their differences are linearly independent?
          – bateman
          Aug 14 at 8:06












          Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
          – John C
          Aug 14 at 12:28




          Yes, that holds in any vector space, the problem I see is exactly checking whether or not they are linearly independent without the inner product. But in theory there is no problem.
          – John C
          Aug 14 at 12:28












           

          draft saved


          draft discarded


























           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2882164%2fon-the-definition-of-k-simplex%23new-answer', 'question_page');

          );

          Post as a guest













































































          這個網誌中的熱門文章

          How to combine Bézier curves to a surface?

          Carbon dioxide

          Why am i infinitely getting the same tweet with the Twitter Search API?