College of Mathematics and Physics, Inner Mongolia Minzu University, Tongliao 028000, China
| Abstract: | Geometric convex function is a parallel concept with convex function and is given by a transformation or an inequality, which generalizes the theory and method of control inequality for convex function. With the concept of geometric convex set being put forward, the properties of geometric convex function based on geometric convex set have been studied. But the properties of geometric convex set and geometric convex function are not perfect. In this paper, we further discuss the properties of geometric convex set and geometric convex function by literature research, analysis, synthesis, induction and deduction. Firstly, based on the concept of geometric convex set, the geometric convex hull and geometric convex combination of a set are defined, and an equivalent condition for judging geometric convex set and an example of geometric convex combination are given. Then, the equivalent definition of geometric convex function is given by using the epigraph, and a judgment theorem of geometric convex function is obtained. In addition, the geometric convex hull of the function is defined, and another judgment theorem of geometric convex function is also obtained by using geometric convex hull of the function. Finally, the invariance of geometric convexity under several operations and the local and global properties of geometric convex functions are studied. The results of this paper will further enrich the theory of geometric convexity. |
| Keywords: | Geometric Convex Function; Geometric Convex Hull; Geometric Convex Combination; Epigraph |
| DOI: | 10.57237/j.wjms.2022.01.003 |
| 1. | 内蒙古自治区直属高校基本科研业务费项目 (2022) |
| 2. | 内蒙古民族大学博士科研启动基金项目 (BS402). |
| [1] | 李世杰. 凸函数Jensen不等式的一个推广及其应用 [J], 抚州师专学报 (自然科学辑刊), 1988, 3: 30-37. |
| [2] | L. G. Lucht. Mittelwertungleichungen fur losungen gewisser differenzengleichungen [J], Aequationes Mathmaticae, 1990, 39: 204-209. |
| [3] | J. Matkowski and L. L. Paranorms. Selected topics in functional equations and iteration theory [C]//Proceedings of the Austrian-Polish seminar, Graz Math. Ber., 1992, 316: 103-138. |
| [4] | C. P. Niculescu. Convexity according to the geometric mean [J], Mathematical Inequalities and Applications, 2000, 3 (2): 155-167. |
| [5] | C. E. Finol and M. Wójtowicz. Multiplicative properties of real functions with applications to classical functions [J], Aequationes Mathmaticae, 2000, 59: 134-149. |
| [6] | 杨露. 关于几何凸函数的不等式 [J]. 河北大学学报(自然科学版), 2002, 22 (4): 325-328. |
| [7] | 吴善和. 几何凸函数与琴生型不等式 [J]. 数学的实践与识, 2002, 32 (2): 155-163. |
| [8] | 张小明. 关于几何凸函数的Hadamard型不等式 [J]. 数学的实践与认识, 2004, 34(9): 171-176. |
| [9] | 张小明. 几何凸函数的几个定理及其应用 [J]. 首都师范大学学报 (自然科学版), 2004, 25 (2): 11-13. |
| [10] | 宋振云. 关于几何凸函数的积分型Jensen不等式 [J]. 湖北职业技术学院学报, 2013, 16 (1): 110-112. |
| [11] | B. Y. Xi, R. F. Bai, F. Qi. Hermite-Hadamard type inequalities for the m- and (α,m)- geometrically convex functions [J]. Aequationes Mathematicae, 2012, 84 (3): 261-269. |
| [12] | A. O. Akdemir, M. Tunç. On some integral inequalities for s-geometrically convex functions and their applications [J]. International Journal of Open Problems in Computer Science and Mathematics, 2012, 6 (1): 1-10. |
| [13] | B. Zhang, B. Y. Xi, F. Qi. Some properties and inequalities for h-geometrically convex functions [J]. Journal of classical analysis, 2019, 3 (2): 101-108. |
| [14] | 刘倩, 王淑红. m-几何凸函数的Hermite-Hadamard型积分不等式 [J]. 湖北民族大学学报 (自然科学版), 2022, 40 (1): 91-95. |
| [15] | 张小明. 几何凸函数 [M]. 合肥: 安徽大学出版社, 2004. |
| [16] | R. T. Roekafellar. Convex analysis [M]. Princeton: Princeton University Press, 1970. |
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