Isomonodromic deformations of systems of linear differential equations with irregular singularities

The talk is devoted to the isomonodromic families of linear differential equations on the Riemann sphere with Fuchsian and irregular (possibly resonant) singular points. The family is the isomonodromic one in the case of preserving monodromy representation and Stokes data. We will proof that any isomonodromic family can be defined by the integrable differential 1-form. Thus it is interesting to discuss a general view of the differential form. In addition some examples of the isomonodromic deformations with irregular resonant singularities will be given.