Groups and Ultra-groups
Subject Areas : StatisticsGh. Moghaddasi 1 , P. Zolfaghari 2 , B. Tolue Haghighi 3
1 - Department of Pure Mathematics, Hakim Sabzevari University, Sabzevar, Iran.
2 - Department of Pure Mathematics, Farhangian University, Mashhad, Iran.
3 - Department of Pure Mathematics, Hakim Sabzevari University, Sabzevar, Iran.
Keywords: همرده, تراگرد, همریختی, فراگروه,
Abstract :
In this paper, in addition to some elementary facts about the ultra-groups, which their structure based on the properties of the transversal of a subgroup of a group, we focus on the relation between a group and an ultra-group. It is verified that every group is an ultra-group, but the converse is not true generally. We present the conditions under which, for every normal subultra-group of an ultra-group over a group, there exists a normal subgroup of that certain group. Moreover, by proving this feature that a monomorphism in groups preserve the ultra-groups over groups, we show that, corresponding to any monomorphism in groups, there is an ultra-group homomorphism on the subgroups of those groups. Finally, we prove isomorphism theorems for ultra-groups. These theorems connect three notions subultra-group, normal subultra-group, quotient ultra-group, and directly, similar to the isomorphism theorems in group theory and module theory are proved.