  In this paper we present a theoretical and numerical analysis of light
localization in hollow core microstructured fibers (HCMFs) with a complicated
shape of the core cladding boundary. The analysis is based on well established
models (for example, the ARROW model) and also on the models proposed for the
first time. In particular, we consider local and nonlocal mechanisms of light
localization in the waveguide structures with a determined type of discrete
rotational symmetry of the core cladding boundary. We interpret and analyze
mechanisms of light localization in negative curvature hollow core
microstructured fibers (NC HCMFs) and simplified HC PCFs with a polygonal shape
of the core cladding boundary.
