<p>Let <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\mathcal {A}\)</EquationSource> </InlineEquation> be an unital <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(C^*\)</EquationSource> </InlineEquation>-algebra and <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(a,b \in \mathcal {A}\)</EquationSource> </InlineEquation>. In this paper, we provide a sufficient condition under which equation <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(a=bx\)</EquationSource> </InlineEquation> has a solution. We also provide a new characterizations of posinormal elements using the Moore-Penrose inverse. Furthermore, we define the notions of ascent and descent of an element to establish that the powers of a posinormal element remain posinormal under specific sufficient conditions.</p>
Some remarkable properties of posinormal element in \(C^*\)-algebras
Let \(\mathcal {A}\) be an unital \(C^*\)-algebra and \(a,b \in \mathcal {A}\). In this paper, we provide a sufficient condition under which equation \(a=bx\) has a solution. We also provide a new characterizations of posinormal elements using the Moore-Penrose inverse. Furthermore, we define the notions of ascent and descent of an element to establish that the powers of a posinormal element remain posinormal under specific sufficient conditions.