@Article{ATA-34-92, author = {M. Iranmanesh and F. Soleimany}, title = {On Quasi-Chebyshevity Subsets of Unital Banach Algebras}, journal = {Analysis in Theory and Applications}, year = {2018}, volume = {34}, number = {1}, pages = {92--102}, abstract = {
In this paper, first, we consider closed convex and bounded subsets of
infinite-dimensional unital Banach algebras and show with regard to the general conditions
that these sets are not quasi-Chebyshev and pseudo-Chebyshev. Examples of
those algebras are given including the algebras of continuous functions on compact
sets. We also see some results in $\rm{C}^*$-algebras and Hilbert $\rm{C}^*$-modules. Next, by considering
some conditions, we study Chebyshev of subalgebras in $\rm{C}^*$-algebras.