# Sh:1216

• Golshani, M., & Shelah, S. Usuba’s principle UB_\lambda can fail at singular cardinals. Preprint. arXiv: 2107.09339
• Abstract:
We answer a question of Usuba by showing that the combinatorial principle UB_\lambda can fail at a singular cardinal. Furthermore, \lambda can be taken to be \aleph_\omega.
• Version 2021-07-20 (8p)
Bib entry
@article{Sh:1216,
author = {Golshani, Mohammad and Shelah, Saharon},
title = {{Usuba's principle $UB_\lambda$ can fail at singular cardinals}},
note = {\href{https://arxiv.org/abs/2107.09339}{arXiv: 2107.09339}},
arxiv_number = {2107.09339}
}