108 citations · 529 across the 96 of their papers we have counts for
5 papers · 1 filter
A new resolvent equation for the S-functional calculus
Daniel Alpay, Fabrizio Colombo, Jonathan Gantner +1
The S-functional calculus is a functional calculus for -tuples of non necessarily commuting operators that can be considered a higher dimensional version of the classical Ri…
Realizations of slice hyperholomorphic generalized contractive and positive functions
Daniel Alpay, Fabrizio Colombo, Izchak Lewkowicz +1
We introduce generalized Schur functions and generalized positive functions in setting of slice hyperholomorphic functions and study their realizations in terms of associated repro…
Self-mappings of the quaternionic unit ball: multiplier properties, Schwarz-Pick inequality, and Nevanlinna--Pick interpolation problem
Daniel Alpay, Vladimir Bolotnikov, Fabrizio Colombo +1
We study several aspects concerning slice regular functions mapping the quaternionic open unit ball into itself. We characterize these functions in terms of their Taylor coefficien…
Inner product spaces and Krein spaces in the quaternionic setting
Daniel Alpay, Fabrizio Colombo, Irene Sabadini
In this paper we provide a study of quaternionic inner product spaces. This includes ortho-complemented subspaces, fundamental decompositions as well as a number of results of topo…
A new integral formula for the inverse Fueter mapping theorem
Fabrizio Colombo, Dixan Peña Peña, Irene Sabadini +1
In this paper we provide an alternative method to construct the Fueter primitive of an axial monogenic function of degree , which is complementary to the one used in [F. Colombo…