  In this work, we propose an extension of the mixed Virtual Element Method
(VEM) for bi-dimensional computational grids with curvilinear edge elements.
The approximation by means of rectilinear edges of a domain with curvilinear
geometrical feature, such as a portion of domain boundary or an internal
interface, may introduce a geometrical error that degrades the expected order
of convergence of the scheme. In the present work a suitable VEM approximation
space is proposed to consistently handle curvilinear geometrical objects, thus
recovering optimal convergence rates. The resulting numerical scheme is
presented along with its theoretical analysis and several numerical test cases
to validate the proposed approach.
