Deep learning may need new mathematics

Many questions related to deep learning can be formulated and analyzed mathematically, but the theoretical understanding of deep learning is very limited. For example, there is definitely no mathematical theory that explains why deep learning works so well. Sometimes ago, the neural networks topic is abandoned by mathematicians. It as a research desert and is not mathematically beautiful. But in current AI wave, deep neural networks work very well in many domains, maybe we need to reconsider deep learning from mathematics point of view.