@article{200176, author = {Felix P. Kemeth and Sindre W. Haugland and Felix Dietrich and Tom Bertalan and Qianxiao Li and Erik M. Bollt and Ronen Talmong and Katharina Krischer and IoannisG. Kevrekidis}, title = {An equal space for complex data with unknown internal order: observability, gauge invariance and manifold learning}, abstract = { We discuss the interplay between manifold-learning tech- niques, which can extract intrinsic order from observations of complex dynamics, and systems modeling considerations. Tuning the scale of the data-mining kernels can guide the construction of dynamic models at different levels of coarse-graining. In particular, we focus on the observability of phys. space from temporal observation data and the transition from spatially resolved to lumped (order- parameter-based) representations, embedded in what we call an "Equal Space". Data-driven coordinates can be extracted in ways invariant to the nature of the measuring instrument. Such gauge-invariant data mining can then go beyond the fusion of heterogeneous observations of the same system, to the possible matching of apparently different systems. These techniques can enhance the scope and applicability of established tools in the anal. of dynamical systems, such as the Takens delay embedding. Our illustrative examples include chimera states (states of co-existing coherent and incoherent dynamics), and chaotic as well as quasiperiodic spatiotemporal dynamics, arising in partial differential equations and/or in heterogeneous networks. }, year = {2017}, journal = {arXiv.org, e-Print Arch., Phys.}, pages = {1-11}, publisher = {Cornell University Library}, url = {https://arxiv.org/abs/1708.05406v1}, language = {eng}, }