An Extension Theorem for a Sequence of Krein Space Contractions. (1st March 2018)

• Record Type: Journal Article
• Authors: Wanjala, Gerald
• Other Names: Popescu Gelu Academic Editor.
• Is Part Of: International journal of mathematics and mathematical sciences. Volume 2018(2018)
• Publication Date: 2018-03-01
• Subjects: Mathematics -- Periodicals; 510.5
• DOI: 10.1155/2018/5178454
• Languages: English
• ISSNs: 0161-1712

Abstract

Abstract : Consider Krein spacesU andY and letH k andK k be regular subspaces ofU andY, respectively, such thatH k ⊂ H k + 1 andK k ⊂ K k + 1 ( k ∈ N ) . For eachk ∈ N, letA k : H k → K k be a contraction. We derive necessary and sufficient conditions for the existence of a contractionB : U → Y such thatB H k = A k . Some interesting results are proved along the way.