报告人：魏益民（复旦大学）

时间：2021年4月15日16:30开始

地点：理科楼LA106

摘要:We present normwise and componentwise perturbation bounds for the LU, the Cholesky, the LDL^T and the QR decompositions by using a new approach. The explicit expressions of mixed and componentwise condition numbers for these matrix decompositions are derived. The condition numbers improve known results of the normwise and componentwise cases and reveal the characterizations of the structured perturbations. The exact explicit perturbation expressions are derived for the factors L and U of the LU decomposition, and the rigorous normwise and componentwise perturbation bounds are presented for the LU decomposition.

简介:魏益民，复旦大学教授、博士生导师，获上海市自然科学三等奖，为上海市高校优秀青年教师和上海市“曙光”学者称号获得者。主要从事矩阵/张量方面的理论和应用研究，在《SIAM J.Matrix Anal. Appl.》《SIAM J. Numer. Anal.》《SIAM J. Sci. Comput.》《J. Sci. Comput.》等权威学术期刊发表论文一百余篇，出版中英文专著3部，英文版教材1部。多次主持国家自然科学基金面上项目、教育部博士点基金项目和973子课题等项目，为《Comput. Appl.Math.》、《J. Appl. Math. Comput.》和《高校计算数学学报》编委。

邀请人：李寒宇