References
Berg, C., Christensen, J. P. R., and Jensen, C. U.,A remark on the multidimensional moment problem, Math. Ann.243(1979), 163–169.
Berg, C., Christensen, J. P. R., and Ressel, P., “Harmonic Analysis on Semigroups,” Springer-Verlag, Berlin, 1984.
Bisgaard, T. M.,Extension of characters on *-semigroups, Math. Ann.282(1988), 251–258.
Kaplansky, I., “Infinite Abelian Groups,” University of Michigan Press, Ann Arbor, 1954.
Sasvári, Z., “Positive Definite and Definitizable Functions,” Akademie Verlag, Berlin, 1994.
Schmüdgen, K.,An example of a positive polynomial which is not a sum of squares of polynomials. A positive, but not strongly positive functional, Math. Nachr.88(1979), 385–390.
Author information
Authors and Affiliations
Additional information
Communicated by Karl H. Hofmann
Rights and permissions
About this article
Cite this article
Bisgaard, T.M. Separation by characters or positive definite functions. Semigroup Forum 53, 317–320 (1996). https://doi.org/10.1007/BF02574146
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02574146