%0 Journal Article
%T Existence of ground states for approximately inner two--parameter $C_0$--groups on $C^*$--algebras
%J Bulletin of the Iranian Mathematical Society
%I Iranian Mathematical Society (IMS)
%Z 1017-060X
%A Abazari, R.
%A Niknam, A.
%D 2016
%\ 04/01/2016
%V 42
%N 2
%P 435-446
%! Existence of ground states for approximately inner two--parameter $C_0$--groups on $C^*$--algebras
%K Two--parameter group
%K Approximately inner dynamical system
%K Tensor product
%K Ground state
%R
%X In this paper, we generalize the definitions of approximately inner $C_0$-groups and their ground states to the two- parameter case and study necessary and sufficient conditions for a state to be ground state. Also we prove that any approximately inner two- parameter $C_0$--group must have at least one ground state. Finally some applications are given.
%U http://bims.iranjournals.ir/article_770_d466d7717510eb9caf6af9b237000141.pdf