Detailed Information on Publication Record
2023
Computing Homotopy Classes for Diagrams
FILAKOVSKÝ, Marek and Lukáš VOKŘÍNEKBasic information
Original name
Computing Homotopy Classes for Diagrams
Authors
FILAKOVSKÝ, Marek and Lukáš VOKŘÍNEK (203 Czech Republic, belonging to the institution)
Edition
Discrete and Computational Geometry, Springer, 2023, 0179-5376
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10101 Pure mathematics
Country of publisher
United States of America
Confidentiality degree
není předmětem státního či obchodního tajemství
References:
Impact factor
Impact factor: 0.800 in 2022
RIV identification code
RIV/00216224:14310/23:00134379
Organization unit
Faculty of Science
UT WoS
001033657400003
Keywords in English
Equivariant homotopy; Algorithm; Tverberg-type problem
Tags
Tags
International impact, Reviewed
Změněno: 16/1/2024 09:18, Mgr. Marie Šípková, DiS.
Abstract
V originále
We present an algorithm that, given finite diagrams of simplicial sets X, A, Y, i.e., functors $${\mathcal {I}}^\textrm{op}\rightarrow {\textsf {s}} {\textsf {Set}}$$ I op → s Set , such that (X, A) is a cellular pair, $$\dim X\le 2\cdot {\text {conn}}Y$$ dim X ≤ 2 · conn Y , $${\text {conn}}Y\ge 1$$ conn Y ≥ 1 , computes the set $$[X,Y]^A$$ [ X , Y ] A of homotopy classes of maps of diagrams $$\ell :X\rightarrow Y$$ ℓ : X → Y extending a given $$f:A\rightarrow Y$$ f : A → Y . For fixed $$n=\dim X$$ n = dim X , the running time of the algorithm is polynomial. When the stability condition is dropped, the problem is known to be undecidable. Using Elmendorf’s theorem, we deduce an algorithm that, given finite simplicial sets X, A, Y with an action of a finite group G, computes the set $$[X,Y]^A_G$$ [ X , Y ] G A of homotopy classes of equivariant maps $$\ell :X\rightarrow Y$$ ℓ : X → Y extending a given equivariant map $$f:A\rightarrow Y$$ f : A → Y under the stability assumption $$\dim X^H\le 2\cdot {\text {conn}}Y^H$$ dim X H ≤ 2 · conn Y H and $${\text {conn}}Y^H\ge 1$$ conn Y H ≥ 1 , for all subgroups $$H\le G$$ H ≤ G . Again, for fixed $$n=\dim X$$ n = dim X , the algorithm runs in polynomial time. We further apply our results to Tverberg-type problem in computational topology: Given a k-dimensional simplicial complex K, is there a map $$K\rightarrow {\mathbb {R}}^d$$ K → R d without r-tuple intersection points? In the metastable range of dimensions, $$rd\ge (r+1) k+3$$ r d ≥ ( r + 1 ) k + 3 , the problem is shown algorithmically decidable in polynomial time when k, d, and r are fixed.
Links
GBP201/12/G028, research and development project |
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