Irreducibility of differential operator?












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Is the differential operator $D:P_n to P_n$ is reducible? Find an element of $P_n$ that is of period $n+1$ under $D$. Here $D$ is Differential operator and $P_n$ is the vector space of all polynomials of degree $n$



Well I know that an operator $D$ is reducible if it has non-trivial $D$-invariant subspace. Further an operator has non-trivial $D$-invariant subspace if its characteristics polynomial splits. I know that for $D$ its characteristics polynomial is $x^{n+1}$.



But I don't think so $D$ has such a subspace.



Am i correct? How to find the element of period $n+1$.










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  • What are $D$ and $P_n$?
    – MaoWao
    Nov 21 '18 at 14:37










  • @MaoWao See edited post.
    – Mittal G
    Nov 21 '18 at 14:42
















0














Is the differential operator $D:P_n to P_n$ is reducible? Find an element of $P_n$ that is of period $n+1$ under $D$. Here $D$ is Differential operator and $P_n$ is the vector space of all polynomials of degree $n$



Well I know that an operator $D$ is reducible if it has non-trivial $D$-invariant subspace. Further an operator has non-trivial $D$-invariant subspace if its characteristics polynomial splits. I know that for $D$ its characteristics polynomial is $x^{n+1}$.



But I don't think so $D$ has such a subspace.



Am i correct? How to find the element of period $n+1$.










share|cite|improve this question
























  • What are $D$ and $P_n$?
    – MaoWao
    Nov 21 '18 at 14:37










  • @MaoWao See edited post.
    – Mittal G
    Nov 21 '18 at 14:42














0












0








0







Is the differential operator $D:P_n to P_n$ is reducible? Find an element of $P_n$ that is of period $n+1$ under $D$. Here $D$ is Differential operator and $P_n$ is the vector space of all polynomials of degree $n$



Well I know that an operator $D$ is reducible if it has non-trivial $D$-invariant subspace. Further an operator has non-trivial $D$-invariant subspace if its characteristics polynomial splits. I know that for $D$ its characteristics polynomial is $x^{n+1}$.



But I don't think so $D$ has such a subspace.



Am i correct? How to find the element of period $n+1$.










share|cite|improve this question















Is the differential operator $D:P_n to P_n$ is reducible? Find an element of $P_n$ that is of period $n+1$ under $D$. Here $D$ is Differential operator and $P_n$ is the vector space of all polynomials of degree $n$



Well I know that an operator $D$ is reducible if it has non-trivial $D$-invariant subspace. Further an operator has non-trivial $D$-invariant subspace if its characteristics polynomial splits. I know that for $D$ its characteristics polynomial is $x^{n+1}$.



But I don't think so $D$ has such a subspace.



Am i correct? How to find the element of period $n+1$.







operator-theory nilpotence invariant-subspace






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 21 '18 at 14:42

























asked Nov 21 '18 at 14:30









Mittal G

1,188515




1,188515












  • What are $D$ and $P_n$?
    – MaoWao
    Nov 21 '18 at 14:37










  • @MaoWao See edited post.
    – Mittal G
    Nov 21 '18 at 14:42


















  • What are $D$ and $P_n$?
    – MaoWao
    Nov 21 '18 at 14:37










  • @MaoWao See edited post.
    – Mittal G
    Nov 21 '18 at 14:42
















What are $D$ and $P_n$?
– MaoWao
Nov 21 '18 at 14:37




What are $D$ and $P_n$?
– MaoWao
Nov 21 '18 at 14:37












@MaoWao See edited post.
– Mittal G
Nov 21 '18 at 14:42




@MaoWao See edited post.
– Mittal G
Nov 21 '18 at 14:42










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