Induced inner product on tensor powers.












1












$begingroup$


Let $V$ be a real or complex inner product space with inner product $leftlangle cdotp,cdotprightrangle$. For $otimes ^kV$ define $leftlangle cdotp,cdotprightrangle_k$ by
$$leftlangle u_1otimes ...otimes u_k,v_1otimes ...otimes v_krightrangle_k = leftlangle u_1,v_1rightrangle...leftlangle u_k,v_krightrangle$$
on pure tensors, and extend bilinearly.



Is the resulting object $leftlangle cdotp,cdotprightrangle_k$ an inner product on $otimes ^kV$? It is clearly a symmetric bilinear form. Is it non-degenerate and positive definite though?










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$endgroup$












  • $begingroup$
    do $v_i=u_i$ for all the $i$ and infer
    $endgroup$
    – janmarqz
    Jan 26 at 17:35










  • $begingroup$
    That only gives the result for tensors of the particular form above.
    $endgroup$
    – Joshua Tilley
    Jan 29 at 19:25










  • $begingroup$
    you need to do that in order to check your last question
    $endgroup$
    – janmarqz
    Jan 30 at 3:23


















1












$begingroup$


Let $V$ be a real or complex inner product space with inner product $leftlangle cdotp,cdotprightrangle$. For $otimes ^kV$ define $leftlangle cdotp,cdotprightrangle_k$ by
$$leftlangle u_1otimes ...otimes u_k,v_1otimes ...otimes v_krightrangle_k = leftlangle u_1,v_1rightrangle...leftlangle u_k,v_krightrangle$$
on pure tensors, and extend bilinearly.



Is the resulting object $leftlangle cdotp,cdotprightrangle_k$ an inner product on $otimes ^kV$? It is clearly a symmetric bilinear form. Is it non-degenerate and positive definite though?










share|cite|improve this question









$endgroup$












  • $begingroup$
    do $v_i=u_i$ for all the $i$ and infer
    $endgroup$
    – janmarqz
    Jan 26 at 17:35










  • $begingroup$
    That only gives the result for tensors of the particular form above.
    $endgroup$
    – Joshua Tilley
    Jan 29 at 19:25










  • $begingroup$
    you need to do that in order to check your last question
    $endgroup$
    – janmarqz
    Jan 30 at 3:23
















1












1








1





$begingroup$


Let $V$ be a real or complex inner product space with inner product $leftlangle cdotp,cdotprightrangle$. For $otimes ^kV$ define $leftlangle cdotp,cdotprightrangle_k$ by
$$leftlangle u_1otimes ...otimes u_k,v_1otimes ...otimes v_krightrangle_k = leftlangle u_1,v_1rightrangle...leftlangle u_k,v_krightrangle$$
on pure tensors, and extend bilinearly.



Is the resulting object $leftlangle cdotp,cdotprightrangle_k$ an inner product on $otimes ^kV$? It is clearly a symmetric bilinear form. Is it non-degenerate and positive definite though?










share|cite|improve this question









$endgroup$




Let $V$ be a real or complex inner product space with inner product $leftlangle cdotp,cdotprightrangle$. For $otimes ^kV$ define $leftlangle cdotp,cdotprightrangle_k$ by
$$leftlangle u_1otimes ...otimes u_k,v_1otimes ...otimes v_krightrangle_k = leftlangle u_1,v_1rightrangle...leftlangle u_k,v_krightrangle$$
on pure tensors, and extend bilinearly.



Is the resulting object $leftlangle cdotp,cdotprightrangle_k$ an inner product on $otimes ^kV$? It is clearly a symmetric bilinear form. Is it non-degenerate and positive definite though?







linear-algebra inner-product-space tensor-products multilinear-algebra






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 22 at 15:23









Joshua TilleyJoshua Tilley

556313




556313












  • $begingroup$
    do $v_i=u_i$ for all the $i$ and infer
    $endgroup$
    – janmarqz
    Jan 26 at 17:35










  • $begingroup$
    That only gives the result for tensors of the particular form above.
    $endgroup$
    – Joshua Tilley
    Jan 29 at 19:25










  • $begingroup$
    you need to do that in order to check your last question
    $endgroup$
    – janmarqz
    Jan 30 at 3:23




















  • $begingroup$
    do $v_i=u_i$ for all the $i$ and infer
    $endgroup$
    – janmarqz
    Jan 26 at 17:35










  • $begingroup$
    That only gives the result for tensors of the particular form above.
    $endgroup$
    – Joshua Tilley
    Jan 29 at 19:25










  • $begingroup$
    you need to do that in order to check your last question
    $endgroup$
    – janmarqz
    Jan 30 at 3:23


















$begingroup$
do $v_i=u_i$ for all the $i$ and infer
$endgroup$
– janmarqz
Jan 26 at 17:35




$begingroup$
do $v_i=u_i$ for all the $i$ and infer
$endgroup$
– janmarqz
Jan 26 at 17:35












$begingroup$
That only gives the result for tensors of the particular form above.
$endgroup$
– Joshua Tilley
Jan 29 at 19:25




$begingroup$
That only gives the result for tensors of the particular form above.
$endgroup$
– Joshua Tilley
Jan 29 at 19:25












$begingroup$
you need to do that in order to check your last question
$endgroup$
– janmarqz
Jan 30 at 3:23






$begingroup$
you need to do that in order to check your last question
$endgroup$
– janmarqz
Jan 30 at 3:23












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