“…For linear problems, many multiscale methods have been developed. These include homogenization-based approaches [5,6], multiscale finite element methods [5,7,8], generalized multiscale finite element methods (GMsFEM) [9,10], constraint energy minimizing GMsFEM (CEM-GMsFEM) [11,12], nonlocal multi-continua (NLMC) approaches [13], metric-based upscaling [14], the heterogeneous multiscale method [15], localized orthogonal decomposition (LOD) [16], equation-free approaches [17,18], multiscale stochastic approaches [19][20][21] and the hierarchical multiscale method [22]. For high-contrast problems, approaches such as GMsFEM and NLMC have been developed.…”