3 papers
math.GR2018
Metabelianisations of finitely presented groups
Ralph Strebel
In this article, I study some classes of finitely presented groups with the aim of finding out whether the maximal metabelian quotients of the members of these classes admit finite…
math.GR2018
A converse to Schreier's index-rank formula
Ralph Strebel
In "Subgroups of free profinite groups and large subfields of Q" (Israel J. Math. 39 (1981), no. 1-2, pages 25-45; MR 617288) A. Lubotzky and L. van den Dries raise the question wh…
math.GR2015
Sigma 1 of PL-homeomorphism groups
Ralph Strebel
I survey the known results about the invariant Sigma 1 of groups of PL-homeomorphisms of a compact interval and supplement them with new results about Sigma 1 of PL-homeomorphism g…