English

Topological complexity of a map

Algebraic Topology 2019-12-04 v3

Abstract

We study certain topological problems that are inspired by applications to autonomous robot manipulation. Consider a continuous map f ⁣:XYf\colon X\to Y, where ff can be a kinematic map from the configuration space XX to the working space YY of a robot arm or a similar mechanism. Then one can associate to ff a number TC(f)\mathrm{TC}(f), which is, roughly speaking, the minimal number of continuous rules that are necessary to construct a complete manipulation algorithm for the device. Examples show that TC(f)\mathrm{TC}(f) is very sensitive to small perturbations of ff and that its value depends heavily on the singularities of ff. This fact considerably complicates the computations, so we focus here on estimates of TC(f)\mathrm{TC}(f) that can be expressed in terms of homotopy invariants of spaces XX and YY, or that are valid if ff satisfy some additional assumptions like, for example, being a fibration. Some of the main results are the derivation of a general upper bound for TC(f)\mathrm{TC}(f), invariance of TC(f)\mathrm{TC}(f) with respect to deformations of the domain and codomain, proof that TC(f)\mathrm{TC}(f) is a FHE-invariant, and the description of a cohomological lower bound for TC(f)\mathrm{TC}(f). Furthermore, if ff is a fibration we derive more precise estimates for TC(f)\mathrm{TC}(f) in terms of the Lusternik-Schnirelmann category and the topological complexity of XX and YY. We also obtain some results for the important special case of covering projections.

Keywords

Cite

@article{arxiv.1809.09021,
  title  = {Topological complexity of a map},
  author = {Petar Pavešić},
  journal= {arXiv preprint arXiv:1809.09021},
  year   = {2019}
}

Comments

Corrected cohomology estimate of topological complexity in Theorem 3.21, which in full generality needs Cech cohomology

R2 v1 2026-06-23T04:16:37.535Z