Absolutely indecomposable quasi-parabolic $G$-bundles and the multiplicity of irreducible characters

Absolutely indecomposable vector bundle and parabolic vector bundles are well-studied via quiver representations. In this paper, we study absolutely indecomposable quasi-parabolic $G$-bundles over ${\mathbb{P}}^1$ with generic additive character varieties. Furthermore, we give a geometric interpretation of the multiplicity of the tensor product of irreducible characters of finite reductive groups using generic additive character varieties.