n-Normal and n-Quasi-normal Composite Multiplication Operator on L2 -Spaces
S. Senthil
Department of Mathematics, Vickram College of Engineering, Enathi, Tamilnadu, India.
P. Thangaraju *
Department of Mathematics, Saraswathi Narayanan College, Madurai, Tamilnadu, India.
D. C. Kumar
Department of Mathematics, Vickram College of Engineering, Enathi, Tamilnadu, India.
*Author to whom correspondence should be addressed.
Abstract
An operator A is called n-normal operator if AnA* =A*An and n-quasi-normal operator if AnA*A =A*AAn . In this paper we characterize the essential isometry, essential co-isometry n-normal and n-quasi-normal composite multiplication operator on L2 -Spaces under certain conditions.
Keywords: Essential isometry, essential co-isometry, n-normal, n-quasi-normal, conditional expectation, composition operator, multiplication operator and composite multiplication operator.