1-Dimensional Topological Invariants to Estimate Loss Surface Non-Convexity

We utilize the framework of topological data analysis to examine the geometry of loss landscape. With the use of topology and Morse theory, we propose to analyse 1-dimensional topological invariants as a measure of loss function non-convexity up to arbitrary re-parametrization. The proposed approach uses optimization of 2-dimensional simplices in network weights space and allows to conduct both qualitative and quantitative evaluation of loss landscape to gain insights into behavior and optimization of neural networks. We provide geometrical interpretation of the topological invariants and describe the algorithm for their computation. We expect that the proposed approach can complement the existing tools for analysis of loss landscape and shed light on unresolved issues in the field of deep learning.