@article{JMLR:v26:24-1131,
  author  = {Lijun Zhang and Yibo Wang and Guanghui Wang and Jinfeng Yi and Tianbao Yang},
  title   = {Universal Online Convex Optimization Meets Second-order Bounds},
  journal = {Journal of Machine Learning Research},
  year    = {2025},
  volume  = {26},
  number  = {152},
  pages   = {1--53},
  url     = {http://jmlr.org/papers/v26/24-1131.html}
}