Document Type : Research Paper

Authors

• Arian Hedayat ¹
• Hossein Mohebi ²

¹ Department of Mathematics, Islamic Azad University, Kerman Branch, Kerman, Iran

² Department of Mathematics, Shahid Bahonar University of Kerman, Kerman, Iran

Abstract

In this paper, we first give a separation theorem for a closed star-shaped set at the origin and a point outside it in terms of separation by an upper semi-continuous and super-linear function, and also, we introduce a $\nu$-star-shaped-conjugation. By using this facts, we present characterizations of the set containment with infinite star-shaped constraints defined by weak inequalities. Next, we give characterizations of the set containment with infinite evenly radiant constraints defined by strict or weak inequalities. Finally, we give a characterization of the set containment with an upper semi-continuous and radiant constraint, in a reverse star-shaped set, defined by a co-star-shaped constraint. These results have many applications in Mathematical Economics, in particular, in Utility Theory.

Keywords

• star-shaped function
• co-star-shaped function
• set containment
• $nu$-star-shaped-conjugation
• weak separation