报 告 人：David Ferreyra 教授

工作单位：阿根廷国家理工大学

举办单位：华体会网页入口

报告人简介：David Ferreyra， 阿根廷国家理工大学教授，2017年获得布宜诺斯艾利斯大学博士学位，目前担任阿根廷数学会理事，支持了阿根廷国家级项目、阿根廷-西班牙双边项目，并与2021.09-2022.09在西班牙瓦伦西亚理工大学访问。目前，David Ferreyra教授已经在Linear Algebra Appl., Linear Multilinear Algebra, Appl. Math. Comput., 等杂志上发表30多篇高质量的论文。

报告题目(1)：An extension of the Rao and Mitra’s crCR-inverse （1）

报告华体会（中国）官方：2023年3月27日（星期一）18:00-19:30

报告地点：腾讯会议：628-762-392

报告简介：In 1972, Rao and Mitra [6] introduced two different types of constraints to extend the concept of Bott-Duffin inverse [1] and define a new constrained inverse for square matrices. In 2011, Mary [4] defined the inverse along an element in a semigroup that generalize the classical generalized inverses (group inverse, Drazin inverse and Moore-Penrose inverse). One year later, Drazin [2] introduced the (b, c)-inverse generalizing Mary’s inverse along an element. Recently, Raki´c [5] noted that Rao and Mitra’s inverse is a direct precursor of the (b, c)-inverse. The main of this talk is to introduce the notion of EF-inverse [3] as a unified approach to the aforementioned generalized inverses. Also, we show that some recent generalized inverses could be considered special cases of this notion.

报告题目(2)：An extension of the Rao and Mitra’s crCR-inverse （2）

报告华体会（中国）官方：2023年3月31日（星期五）18:00-19:30

报告地点：腾讯会议：197-974-473

报告简介：In 1972, Rao and Mitra [6] introduced two different types of constraints to extend the concept of Bott-Duffin inverse [1] and define a new constrained inverse for square matrices. In 2011, Mary [4] defined the inverse along an element in a semigroup that generalize the classical generalized inverses (group inverse, Drazin inverse and Moore-Penrose inverse). One year later, Drazin [2] introduced the (b, c)-inverse generalizing Mary’s inverse along an element. Recently, Raki´c [5] noted that Rao and Mitra’s inverse is a direct precursor of the (b, c)-inverse. The main of this talk is to introduce the notion of EF-inverse [3] as a unified approach to the aforementioned generalized inverses. Also, we show that some recent generalized inverses could be considered special cases of this notion.

报告题目(3)：Several types of generalized inverses

报告华体会（中国）官方：2023年4月3日（星期一）14:00-15:00

报告地点：腾讯会议：193-211-292

报告简介：From the point of view of generalizations, the core inverse of a matrix has received a lot of attention of researchers in this area resulting in many generalizations of the core inverse, like core-EP, DMP, BT, WC and so on. However, the same can not be said for the group inverse. In this paper we introduce a new g-inverse for a matrix of arbitrary index that generalizes the group inverse as it coincides with its group inverse in case the matrix has index at most 1 and call it GG (generalized group) inverse. We study several properties and characterizations of this extension by using the core-EP decomposition. Apart from investing it for its properties and characterizations, we study the several features it has common with the group inverse. In addition, by using Drazin and GG inverses we introduce a new class of matrices that extends the concept of WC matrix recently defined in the literature

报告题目(4)：Characterizations for EP elements

报告华体会（中国）官方：2023年4月7日（星期五）14:00-15:00

报告地点：腾讯会议：814-575-525

报告题目：Characterizations for EP elements

报告简介：weaker equivalent conditions for an operator G to be the Moore-Penrose inverse of A are investigated in terms of normal, EP, bi-normal, bi-EP, quasi-normal and r-quasi-normal and quasi-EP and r-quasi-EP operators.