Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
In this paper, we consider the problem of computing the rank of a block-structured symbolic matrix (a generic partitioned matrix) [Formula omitted], where [Formula omitted] is a [Formula omitted] matrix over a field [Formula omitted] and [Formula omitted] is an indeterminate for [Formula omitted] and [Formula omitted]. This problem can be viewed as an algebraic generalization of the bipartite matching problem and was considered by Iwata and Murota (SIAM J Matrix Anal Appl 16(3):719-734, 1995). Recent interests in this problem lie in the connection with non-commutative Edmonds' problem by Ivanyos et al. (Comput Complex 27:561-593, 2018) and Garg et al. (Found. Comput. Math. 20:223-290, 2020), where a result by Iwata and Murota implicitly states that the rank and non-commutative rank (nc-rank) are the same for this class of symbolic matrices. The main result of this paper is a simple and combinatorial [Formula omitted]-time algorithm for computing the symbolic rank of a [Formula omitted]-type generic partitioned matrix of size [Formula omitted]. Our algorithm is inspired by the Wong sequence algorithm by Ivanyos et al. for the nc-rank of a general symbolic matrix, and requires no blow-up operation, no field extension, and no additional care for bounding the bit-size. Moreover it naturally provides a maximum rank completion of A for an arbitrary field [Formula omitted].