For $U$ a $G-$invariant subspace of $V$ a $G-$representation, show that $T_g(U)=U$












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Prove that if the subspace $U$ of the space of the representation $T:Gto GL(V)$ of $G$ is invariant, then $T(g)U = U$ for all $g in G.$



Could any one give me a hint how to solve this question ?










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    0












    $begingroup$


    Prove that if the subspace $U$ of the space of the representation $T:Gto GL(V)$ of $G$ is invariant, then $T(g)U = U$ for all $g in G.$



    Could any one give me a hint how to solve this question ?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Prove that if the subspace $U$ of the space of the representation $T:Gto GL(V)$ of $G$ is invariant, then $T(g)U = U$ for all $g in G.$



      Could any one give me a hint how to solve this question ?










      share|cite|improve this question











      $endgroup$




      Prove that if the subspace $U$ of the space of the representation $T:Gto GL(V)$ of $G$ is invariant, then $T(g)U = U$ for all $g in G.$



      Could any one give me a hint how to solve this question ?







      representation-theory invariant-theory






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      edited Jan 22 at 21:00









      Antonios-Alexandros Robotis

      10.5k41741




      10.5k41741










      asked Jan 22 at 20:48









      IntuitionIntuition

      1,089826




      1,089826






















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          $begingroup$

          Well, I'm assuming $V$ is a $mathbb{C}-$vector space and $T:Gto GL(V)$ is your representation. The fact that $U$ is $G-$invariant means that for each element $gin G$ $T_g(U)subseteq U$. However, we also know that $T_g$ is a nonsingular linear transformation, so $dim T_g(U)=dim U$ so, $T_g(U)=U$.






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            1 Answer
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            $begingroup$

            Well, I'm assuming $V$ is a $mathbb{C}-$vector space and $T:Gto GL(V)$ is your representation. The fact that $U$ is $G-$invariant means that for each element $gin G$ $T_g(U)subseteq U$. However, we also know that $T_g$ is a nonsingular linear transformation, so $dim T_g(U)=dim U$ so, $T_g(U)=U$.






            share|cite|improve this answer









            $endgroup$


















              2












              $begingroup$

              Well, I'm assuming $V$ is a $mathbb{C}-$vector space and $T:Gto GL(V)$ is your representation. The fact that $U$ is $G-$invariant means that for each element $gin G$ $T_g(U)subseteq U$. However, we also know that $T_g$ is a nonsingular linear transformation, so $dim T_g(U)=dim U$ so, $T_g(U)=U$.






              share|cite|improve this answer









              $endgroup$
















                2












                2








                2





                $begingroup$

                Well, I'm assuming $V$ is a $mathbb{C}-$vector space and $T:Gto GL(V)$ is your representation. The fact that $U$ is $G-$invariant means that for each element $gin G$ $T_g(U)subseteq U$. However, we also know that $T_g$ is a nonsingular linear transformation, so $dim T_g(U)=dim U$ so, $T_g(U)=U$.






                share|cite|improve this answer









                $endgroup$



                Well, I'm assuming $V$ is a $mathbb{C}-$vector space and $T:Gto GL(V)$ is your representation. The fact that $U$ is $G-$invariant means that for each element $gin G$ $T_g(U)subseteq U$. However, we also know that $T_g$ is a nonsingular linear transformation, so $dim T_g(U)=dim U$ so, $T_g(U)=U$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 22 at 20:58









                Antonios-Alexandros RobotisAntonios-Alexandros Robotis

                10.5k41741




                10.5k41741






























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