2008/11/28 by Luis Ribes, Ribes, Luis, Benjamin Steinberg +1
Computer Science · Mathematics · #20E06 #20E07 #20E22 #FOS: Mathematics #Geometric and Algebraic Topology #Group Theory (math.GR) #Homotopy and Cohomology in Algebraic Topology #math.GR #msc:20E06 #msc:20E07 #msc:20E22 #semigroups and automata theory
paper · pdf · doi:10.48550/arxiv.0812.0027
openalex publication_date 2008/11/28 · arxiv created 2008/12/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We provide elementary proofs of the Nielsen-Schreier Theorem and the Kurosh Subgroup Theorem via wreath products. Our proofs are diagrammatic in nature and work simultaneously in the abstract and profinite categories. A new proof that open subgroups of quasifree profinite groups are quasifree is also given.