@article{lowerboundsforsmoothnonconvexfinitesum,
  title = {Lower Bounds for Smooth Nonconvex Finite-Sum Optimization},
  author = {Dongruo Zhou and Quanquan Gu},
  year = {2019},
  eprint = {1901.11224},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1901.11224v1},
}