For a linear relation in a linear space the concepts of ascent, descent, nullity, and defect are
introduced and studied. It is shown that the results of AE Taylor and MA Kaashoek …

The concept of multivalued linear operators—or linear relations—is the one of the most
exciting and influential fields of research in modern mathematics. Applications of this theory …

For a closed linear relation in a Banach space the concept of regularity is introduced and
studied. It is shown that many of the results of Mbekhta and other authors for operators …

In this paper, we study the descent spectrum and the essential descent spectrum of linear
relations everywhere defined on Banach spaces. We prove that the corresponding spectra …

For a closed linear relation everywhere defined on a Hilbert space the concepts of isometry,
co-isometry, partial isometry, and generalized inverse are introduced and studied. Part of the …

In this paper, we study the essentially semi-regular linear relation operators everywhere
defined in Hilbert space. We establish a Kato-type decomposition of essentially semi-regular …

ON 𝑘-STRICTLY QUASI-FREDHOLM LINEAR RELATIONS Page 1 Mathematica Pannonica
New Series 29 /NS 3/ (2023) 2, 204–218 DOI: 10.1556/314.2023.00021 ON 𝑘-STRICTLY …

For a closed linear relation everywhere defined and acting between two Banach spaces the
concepts of essential minimum modulus and essential surjectivity modulus are introduced …

The Baire category theorem for operators, concerning the denseness of the intersection of
the ranges of certain sequences of continuous operators in Banach spaces, is generalized …

In the present paper we introduce the notion of a positive linear relation and we investigate
the class of such operators. As well as placing the theory of positive operators in a natural …