How to find Jordan blocks from minimal polynomial

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











up vote
1
down vote

favorite












If the characteristic polynomial is $p=(x-λ)^6$ and the minimal polynomial is $p=(x-λ)^4,$ how do we find all the Jordan blocks?







share|cite|improve this question






















  • Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
    – ancientmathematician
    Apr 18 at 17:01















up vote
1
down vote

favorite












If the characteristic polynomial is $p=(x-λ)^6$ and the minimal polynomial is $p=(x-λ)^4,$ how do we find all the Jordan blocks?







share|cite|improve this question






















  • Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
    – ancientmathematician
    Apr 18 at 17:01













up vote
1
down vote

favorite









up vote
1
down vote

favorite











If the characteristic polynomial is $p=(x-λ)^6$ and the minimal polynomial is $p=(x-λ)^4,$ how do we find all the Jordan blocks?







share|cite|improve this question














If the characteristic polynomial is $p=(x-λ)^6$ and the minimal polynomial is $p=(x-λ)^4,$ how do we find all the Jordan blocks?









share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Aug 12 at 18:56









Maurice P

1,1601630




1,1601630










asked Apr 18 at 16:42









Jone Will

333




333











  • Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
    – ancientmathematician
    Apr 18 at 17:01

















  • Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
    – ancientmathematician
    Apr 18 at 17:01
















Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
– ancientmathematician
Apr 18 at 17:01





Hint 1: what are the possibilities, given what you know? Hint 2: what is the rank of $A-lambda I$?
– ancientmathematician
Apr 18 at 17:01











1 Answer
1






active

oldest

votes

















up vote
0
down vote













From your characteristic polynomial, we see that the matrix has size six-by-six (so the sum of the lengths of the Jordan blocks is six) and only one eigenvalue. From the minimal polynomial, we see that one Jordan block must have length four. That leaves two possibilities for the Jordan blocks:
$$beginpmatrix
lambda & 1 & 0 & 0\
0 & lambda & 1 & 0\
0 & 0 & lambda & 1\
0 & 0 & 0 & lambda\
endpmatrix,
beginpmatrix
lambda & 1\
0 & lambda\
endpmatrix mboxor$$
$$beginpmatrix
lambda & 1 & 0 & 0\
0 & lambda & 1 & 0\
0 & 0 & lambda & 1\
0 & 0 & 0 & lambda\
endpmatrix,
beginpmatrix
lambda
endpmatrix,
beginpmatrix
lambda
endpmatrix.$$






share|cite|improve this answer






















    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%2f2743339%2fhow-to-find-jordan-blocks-from-minimal-polynomial%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
    0
    down vote













    From your characteristic polynomial, we see that the matrix has size six-by-six (so the sum of the lengths of the Jordan blocks is six) and only one eigenvalue. From the minimal polynomial, we see that one Jordan block must have length four. That leaves two possibilities for the Jordan blocks:
    $$beginpmatrix
    lambda & 1 & 0 & 0\
    0 & lambda & 1 & 0\
    0 & 0 & lambda & 1\
    0 & 0 & 0 & lambda\
    endpmatrix,
    beginpmatrix
    lambda & 1\
    0 & lambda\
    endpmatrix mboxor$$
    $$beginpmatrix
    lambda & 1 & 0 & 0\
    0 & lambda & 1 & 0\
    0 & 0 & lambda & 1\
    0 & 0 & 0 & lambda\
    endpmatrix,
    beginpmatrix
    lambda
    endpmatrix,
    beginpmatrix
    lambda
    endpmatrix.$$






    share|cite|improve this answer


























      up vote
      0
      down vote













      From your characteristic polynomial, we see that the matrix has size six-by-six (so the sum of the lengths of the Jordan blocks is six) and only one eigenvalue. From the minimal polynomial, we see that one Jordan block must have length four. That leaves two possibilities for the Jordan blocks:
      $$beginpmatrix
      lambda & 1 & 0 & 0\
      0 & lambda & 1 & 0\
      0 & 0 & lambda & 1\
      0 & 0 & 0 & lambda\
      endpmatrix,
      beginpmatrix
      lambda & 1\
      0 & lambda\
      endpmatrix mboxor$$
      $$beginpmatrix
      lambda & 1 & 0 & 0\
      0 & lambda & 1 & 0\
      0 & 0 & lambda & 1\
      0 & 0 & 0 & lambda\
      endpmatrix,
      beginpmatrix
      lambda
      endpmatrix,
      beginpmatrix
      lambda
      endpmatrix.$$






      share|cite|improve this answer
























        up vote
        0
        down vote










        up vote
        0
        down vote









        From your characteristic polynomial, we see that the matrix has size six-by-six (so the sum of the lengths of the Jordan blocks is six) and only one eigenvalue. From the minimal polynomial, we see that one Jordan block must have length four. That leaves two possibilities for the Jordan blocks:
        $$beginpmatrix
        lambda & 1 & 0 & 0\
        0 & lambda & 1 & 0\
        0 & 0 & lambda & 1\
        0 & 0 & 0 & lambda\
        endpmatrix,
        beginpmatrix
        lambda & 1\
        0 & lambda\
        endpmatrix mboxor$$
        $$beginpmatrix
        lambda & 1 & 0 & 0\
        0 & lambda & 1 & 0\
        0 & 0 & lambda & 1\
        0 & 0 & 0 & lambda\
        endpmatrix,
        beginpmatrix
        lambda
        endpmatrix,
        beginpmatrix
        lambda
        endpmatrix.$$






        share|cite|improve this answer














        From your characteristic polynomial, we see that the matrix has size six-by-six (so the sum of the lengths of the Jordan blocks is six) and only one eigenvalue. From the minimal polynomial, we see that one Jordan block must have length four. That leaves two possibilities for the Jordan blocks:
        $$beginpmatrix
        lambda & 1 & 0 & 0\
        0 & lambda & 1 & 0\
        0 & 0 & lambda & 1\
        0 & 0 & 0 & lambda\
        endpmatrix,
        beginpmatrix
        lambda & 1\
        0 & lambda\
        endpmatrix mboxor$$
        $$beginpmatrix
        lambda & 1 & 0 & 0\
        0 & lambda & 1 & 0\
        0 & 0 & lambda & 1\
        0 & 0 & 0 & lambda\
        endpmatrix,
        beginpmatrix
        lambda
        endpmatrix,
        beginpmatrix
        lambda
        endpmatrix.$$







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Aug 12 at 17:04

























        answered Aug 11 at 20:51









        Maurice P

        1,1601630




        1,1601630






















             

            draft saved


            draft discarded


























             


            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2743339%2fhow-to-find-jordan-blocks-from-minimal-polynomial%23new-answer', 'question_page');

            );

            Post as a guest













































































            這個網誌中的熱門文章

            tkz-euclide: tkzDrawCircle[R] not working

            How to combine Bézier curves to a surface?

            1st Magritte Awards