曹志強 杜乃林

摘 要： 研究了兩個Lp.s.d.矩陣廣義BottDuffin逆的逆序律問題，Lp.s.d.是半正定概念的一種推廣，正定或半正定矩陣恰是R np.s.d.矩陣.通過建立廣義BottDuffin逆與A（2）S，S⊥逆之間的關(guān)系，利用A（2）S，S⊥的性質(zhì)，得到了廣義BottDuffin逆序律成立的充要條件，并通過兩個實例驗證了所得結(jié)果.

關(guān)鍵詞： 逆序律; Lp.s.d.矩陣; 廣義BottDuffin逆

中圖分類號： O 151.21? 文獻標(biāo)志碼： A? 文章編號： 10005137（2019）04034709

Abstract： In this paper we investigate the reverse order law for the generalized BottDuffin inverses of two Lp.s.d.matrices.The concept of Lp.s.d.matrices is a generalization of semipositive definiteness，in the sense that Rnp.s.d.matrices are exactly semipositive definite matrices.We establish a relationship between generalized BottDuffin inverses and A（2）S，S⊥ inverses，and by using their properties，give necessary and sufficient conditions for the reverse order law of the generalized BottDuffin inverses.In the end we give two explicit examples to test our results.

Key words： reverse order law; Lp.s.d.matrix; generalized BottDuffin inverse

參考文獻：

[1] PENROSE R.A Generalized Inverse for Matrices [M].Cambridge：Cambridge University Press，1955：406-413.

[2] GREVILLE T N E.Note on the generalized inverse of a matrix product [J].Siam Review，1966，8（4）：518-521.

[3] HARTWIG R E.The reverse order law revisited [J].Linear Algebra and Its Applications，1986，76：241-246.

[4] TIAN Y.Reverse order laws for the generalized inverses of multiple matrix products [J].Linear Algebra and Its Applications，1994，211：85-100.

[5] SHINOZAKI N，SIBUYA M.The reverse order law （AB）- = B- A- [J].Linear Algebra and Its Applications，1974，9：29-40.

[6] WEI M.Reverse order laws for generalized inverses of multiple matrix products [J].Linear Algebra and Its Applications，1999，293（1/2/3）：273-288.

[7] ZHENG B，XIONG Z P.The reverse order laws for 1，2，3and 1，2，4inverses of multiple matrix products [J].Linear and Multilinear Algebra，2010，58（6）：765-782.

[8] TIAN H J.On the reverse order law （AB）D= BDAD [J].Journal of Mathematical Research Exposition，1999，19：355-358.

[9] CAO C，ZHANG X，TANG X.Reverse order law of group inverses of products of two matrices [J].Applied Mathematics and Computation，2004，158（2）：489-495.

[10] WANG G，WEI Y，QIAO S.Generalized Inverses：Theory and Computations [M].Beijing：Science Press，2004：113-211.

[11] BOTT R，DUFFIN R J.On the algebra of networks [J].Transactions of the American Mathematical Society，1953，74（1）：99-109.

[12] GREVILLE T N E，BENISRAEL A.Generalized Inverses：Theory and Applications [M].New York：Wiley，1974：112-115.

[13] CHEN Y L.The generalized BottDuffin inverse and its applications [J].Linear Algebra and Its Applications，1990，134：71-91.

[14] YU Y M，WANG G R.The existence of the generalized inverse A（2）T，S of a matrix A over skew fields [J].Journal of Shanghai Normal University （Natural Sciences），2007，36（2）：1-5.

[15] YU Y，WANG G.The generalized inverse A（2）T，S of a matrix over an associative ring [J].Journal of the Australian Mathematical Society，2007，83（3）：423-438.

（責(zé)任編輯：馮珍珍）