  In this paper, we investigate inexact variants of dual-primal isogeometric
tearing and interconnecting methods for solving large-scale systems of linear
equations arising from Galerkin isogeometric discretizations of elliptic
boundary value problems. The considered methods are extensions of standard
finite element tearing and interconnecting methods to isogeometric analysis.
The algorithms are implemented by means of energy minimizing primal subspaces.
We discuss the replacement of local sparse direct solvers by iterative methods,
particularly, multigrid solvers. We investigate the incorporation of these
iterative solvers into different formulations of the algorithm. Finally, we
present numerical examples comparing the performance of these inexact versions.
