Decomposability of minimal defect branched coverings over the projective plane

In this paper, we characterize primitive branched coverings with minimal defect over the projective plane with respect to the properties decomposable indecomposable. Minimality is achieved in the case the covering surface is the projective plane. As a consequence, we obtain a larger class of realisations than given in [A. L. Edmonds, R. S. Kulkarni and R. E. Stong, Realizability of branched coverings of surfaces, Trans. Am. Math. Soc. 282 (1984) 773–790, doi:10.2307/1999265].