On $QR$ factorization of upper Hessenberg matrices with real entries












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Let $A$ be an $ntimes n$ invertible upper Hessenberg matrix (https://en.wikipedia.org/wiki/Hessenberg_matrix) with real entries. I am trying to prove the following three statements :



(1) There exists decomposition $A=QR$ where $Q$ is orthogonal and $R$ is upper triangular and $Q=H_1...H_{n-1}$ for some Householder matrices $H_1,...,H_{n-1}$. (https://en.wikipedia.org/wiki/Householder_transformation )



(2) $Q$ as in (1) is upper Hessenberg



(3) $RQ$, where $Q,R$ are as in (1), is upper Hessenberg.



Any proof or any reference of the statements with proof will be greatly appreciated.



Thanks in advance










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$endgroup$

















    0












    $begingroup$


    Let $A$ be an $ntimes n$ invertible upper Hessenberg matrix (https://en.wikipedia.org/wiki/Hessenberg_matrix) with real entries. I am trying to prove the following three statements :



    (1) There exists decomposition $A=QR$ where $Q$ is orthogonal and $R$ is upper triangular and $Q=H_1...H_{n-1}$ for some Householder matrices $H_1,...,H_{n-1}$. (https://en.wikipedia.org/wiki/Householder_transformation )



    (2) $Q$ as in (1) is upper Hessenberg



    (3) $RQ$, where $Q,R$ are as in (1), is upper Hessenberg.



    Any proof or any reference of the statements with proof will be greatly appreciated.



    Thanks in advance










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      Let $A$ be an $ntimes n$ invertible upper Hessenberg matrix (https://en.wikipedia.org/wiki/Hessenberg_matrix) with real entries. I am trying to prove the following three statements :



      (1) There exists decomposition $A=QR$ where $Q$ is orthogonal and $R$ is upper triangular and $Q=H_1...H_{n-1}$ for some Householder matrices $H_1,...,H_{n-1}$. (https://en.wikipedia.org/wiki/Householder_transformation )



      (2) $Q$ as in (1) is upper Hessenberg



      (3) $RQ$, where $Q,R$ are as in (1), is upper Hessenberg.



      Any proof or any reference of the statements with proof will be greatly appreciated.



      Thanks in advance










      share|cite|improve this question









      $endgroup$




      Let $A$ be an $ntimes n$ invertible upper Hessenberg matrix (https://en.wikipedia.org/wiki/Hessenberg_matrix) with real entries. I am trying to prove the following three statements :



      (1) There exists decomposition $A=QR$ where $Q$ is orthogonal and $R$ is upper triangular and $Q=H_1...H_{n-1}$ for some Householder matrices $H_1,...,H_{n-1}$. (https://en.wikipedia.org/wiki/Householder_transformation )



      (2) $Q$ as in (1) is upper Hessenberg



      (3) $RQ$, where $Q,R$ are as in (1), is upper Hessenberg.



      Any proof or any reference of the statements with proof will be greatly appreciated.



      Thanks in advance







      linear-algebra matrices






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      share|cite|improve this question











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      asked Jan 16 at 12:49









      user521337user521337

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