4 citations · 6 across the 15 of their papers we have counts for
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Strip-type operators and abstract Cauchy problems
Nikolaos Roidos
We consider the non-homogeneous abstract linear Schrödinger and wave equations with zero initial conditions, defined by operators of strip-type and parabola-type in Banach spaces,…
Heinz-Kato inequality in Banach spaces
Nikolaos Roidos
It is observed that in Banach spaces, sectorial operators having bounded imaginary powers satisfy a Heinz-Kato inequality.
Closedness and invertibility for the sum of two closed operators
Nikolaos Roidos
We show a Kalton-Weis type theorem for the general case of non-commuting operators. More precisely, we consider sums of two possibly non-commuting linear operators defined in a Ban…
Preserving closedness of operators under summation
Nikolaos Roidos
We give a sufficient condition for the sum of two closed operators to be closed. In particular, we study the sum of two sectorial operators with the sum of their sectoriality angle…
On the inverse of the sum of two sectorial operators
Nikolaos Roidos
We study an abstract linear operator equation on a Banach space by using the inverse of the sum of two sectorial operators. We prove that the boundedness of a special type of opera…