English

Fibrations, unique path lifting, and continuous monodromy

Algebraic Topology 2020-01-01 v2

Abstract

Given a path-connected space XX and Hπ1(X,x0)H\leq\pi_1(X,x_0), there is essentially only one construction of a map pH:(X~H,x~0)(X,x0)p_H:(\widetilde{X}_H,\widetilde{x}_0)\rightarrow(X,x_0) with connected and locally path-connected domain that can possibly have the following two properties: (pH)#π1(X~H,x~0)=H(p_{H})_{\#}\pi_1(\widetilde{X}_H,\widetilde{x}_0)=H and pHp_H has the unique lifting property. X~H\widetilde{X}_H consists of equivalence classes of paths starting at x0x_0, appropriately topologized, and pHp_H is the endpoint projection. For pHp_H to have these two properties, T1T_1 fibers are necessary and unique path lifting is sufficient. However, pHp_H always admits the standard lifts of paths. We show that pHp_H has unique path lifting if it has continuous (standard) monodromies toward a T1T_1 fiber over x0x_0. Assuming, in addition, that HH is locally quasinormal (e.g., if HH is normal) we show that XX is homotopically path Hausdorff relative to HH. We show that pHp_H is a fibration if XX is locally path connected, HH is locally quasinormal, and all (standard) monodromies are continuous.

Cite

@article{arxiv.1902.00081,
  title  = {Fibrations, unique path lifting, and continuous monodromy},
  author = {Hanspeter Fischer and Jacob D. Garcia},
  journal= {arXiv preprint arXiv:1902.00081},
  year   = {2020}
}

Comments

9 pages; revised abstract and introduction for version 2

R2 v1 2026-06-23T07:28:47.359Z