2009/03/15 by Ronald Brown, Brown, Ronald
Mathematics · #18B40 #18D05 #55E30 #Advanced Topics in Algebra #Algebraic Topology (math.AT) #Algebraic structures and combinatorial models #Category Theory (math.CT) #FOS: Mathematics #Homotopy and Cohomology in Algebraic Topology #math.AT #math.CT #msc:18B40 #msc:18D05 #msc:55E30
paper · pdf · doi:10.48550/arxiv.0903.2627
7 pages, 1 figure, QED.sty v.2 This version explains and proves the relation of the homotopy double groupoid with two second relative homotopy groups. Also extra references added
openalex publication_date 2009/03/15 · arxiv created 2009/03/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We give a rather general construction of double categories and so, under further conditions, double groupoids, from a structure we call a `double module'. We also give a homotopical construction of a double groupoid from a triad consisting of a space, two subspaces, and a set of base points, under a condition which also implies that this double groupoid contains two second relative homotopy groups.