Importance of pure states in $C^{*}$ algebras












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In a tensor product of $C^{*}$-algebras I have seen some proofs are used by the argument of norms by pure states. Why pure states are essential to study related to vN algebras and $C^{*}$-algebras?










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    $begingroup$


    In a tensor product of $C^{*}$-algebras I have seen some proofs are used by the argument of norms by pure states. Why pure states are essential to study related to vN algebras and $C^{*}$-algebras?










    share|cite|improve this question









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      $begingroup$


      In a tensor product of $C^{*}$-algebras I have seen some proofs are used by the argument of norms by pure states. Why pure states are essential to study related to vN algebras and $C^{*}$-algebras?










      share|cite|improve this question









      $endgroup$




      In a tensor product of $C^{*}$-algebras I have seen some proofs are used by the argument of norms by pure states. Why pure states are essential to study related to vN algebras and $C^{*}$-algebras?







      von-neumann-algebras






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      asked Jan 15 at 7:14









      mathlovermathlover

      119110




      119110






















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          The question is fairly broad, but here are a couple things:




          • the pure states are the extreme points of the state space. So any property that holds for pure states and survives convex combinations and pointiwse limits, holds for all states.


          • pure states are "minimal", in the sense that if $psileqphi$ with both states and $phi$ pure, then $psi=c,phi$ for some $c>0$.


          • the GNS representation of a pure state is irreducible.



          Without thinking of a specific case, this is as far as I can go.






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            $begingroup$

            The question is fairly broad, but here are a couple things:




            • the pure states are the extreme points of the state space. So any property that holds for pure states and survives convex combinations and pointiwse limits, holds for all states.


            • pure states are "minimal", in the sense that if $psileqphi$ with both states and $phi$ pure, then $psi=c,phi$ for some $c>0$.


            • the GNS representation of a pure state is irreducible.



            Without thinking of a specific case, this is as far as I can go.






            share|cite|improve this answer









            $endgroup$


















              1












              $begingroup$

              The question is fairly broad, but here are a couple things:




              • the pure states are the extreme points of the state space. So any property that holds for pure states and survives convex combinations and pointiwse limits, holds for all states.


              • pure states are "minimal", in the sense that if $psileqphi$ with both states and $phi$ pure, then $psi=c,phi$ for some $c>0$.


              • the GNS representation of a pure state is irreducible.



              Without thinking of a specific case, this is as far as I can go.






              share|cite|improve this answer









              $endgroup$
















                1












                1








                1





                $begingroup$

                The question is fairly broad, but here are a couple things:




                • the pure states are the extreme points of the state space. So any property that holds for pure states and survives convex combinations and pointiwse limits, holds for all states.


                • pure states are "minimal", in the sense that if $psileqphi$ with both states and $phi$ pure, then $psi=c,phi$ for some $c>0$.


                • the GNS representation of a pure state is irreducible.



                Without thinking of a specific case, this is as far as I can go.






                share|cite|improve this answer









                $endgroup$



                The question is fairly broad, but here are a couple things:




                • the pure states are the extreme points of the state space. So any property that holds for pure states and survives convex combinations and pointiwse limits, holds for all states.


                • pure states are "minimal", in the sense that if $psileqphi$ with both states and $phi$ pure, then $psi=c,phi$ for some $c>0$.


                • the GNS representation of a pure state is irreducible.



                Without thinking of a specific case, this is as far as I can go.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 15 at 17:51









                Martin ArgeramiMartin Argerami

                126k1182181




                126k1182181






























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