How to prove the inequality $lambda_{min{B^TAB}} geq lambda_{min{A}}lambda_{min{B^TB}}$?












-1














Given an arbitrary positive definite symmetric matrix $A$ and an arbitrary non-singular matrix $B$, let $lambda_{min{X}}$ represents the minimum eigenvalue of the matrix $X$. Can we obtain the eigenvalues inequality
$lambda_{min{B^TAB}} geq lambda_{min{A}}lambda_{min{B^TB}}$?



I have tried many examples and find it indeed works, but I cannot figure it out.



Thanks a lot!










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    -1














    Given an arbitrary positive definite symmetric matrix $A$ and an arbitrary non-singular matrix $B$, let $lambda_{min{X}}$ represents the minimum eigenvalue of the matrix $X$. Can we obtain the eigenvalues inequality
    $lambda_{min{B^TAB}} geq lambda_{min{A}}lambda_{min{B^TB}}$?



    I have tried many examples and find it indeed works, but I cannot figure it out.



    Thanks a lot!










    share|cite|improve this question







    New contributor




    KevenSun is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      -1












      -1








      -1







      Given an arbitrary positive definite symmetric matrix $A$ and an arbitrary non-singular matrix $B$, let $lambda_{min{X}}$ represents the minimum eigenvalue of the matrix $X$. Can we obtain the eigenvalues inequality
      $lambda_{min{B^TAB}} geq lambda_{min{A}}lambda_{min{B^TB}}$?



      I have tried many examples and find it indeed works, but I cannot figure it out.



      Thanks a lot!










      share|cite|improve this question







      New contributor




      KevenSun is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      Given an arbitrary positive definite symmetric matrix $A$ and an arbitrary non-singular matrix $B$, let $lambda_{min{X}}$ represents the minimum eigenvalue of the matrix $X$. Can we obtain the eigenvalues inequality
      $lambda_{min{B^TAB}} geq lambda_{min{A}}lambda_{min{B^TB}}$?



      I have tried many examples and find it indeed works, but I cannot figure it out.



      Thanks a lot!







      matrices eigenvalues-eigenvectors






      share|cite|improve this question







      New contributor




      KevenSun is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











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