48 citations · 67 across the 9 of their papers we have counts for
Showing 2006Show all
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math.GT2006★ 5 cited
Topological minimal genus and -signatures
Jae Choon Cha
We obtain new lower bounds of the minimal genus of a locally flat surface representing a 2-dimensional homology class in a topological 4-manifold with boundary, using the von Neuma…
math.GT2006★ 48 cited
The structure of the rational concordance group of knots
Jae Choon Cha
We study the group of rational concordance classes of codimension two knots in rational homology spheres. We give a full calculation of its algebraic theory by developing a complet…
math.GT2006
Injectivity theorems and algebraic closures of groups with coefficients
Jae Choon Cha
Recently, Cochran and Harvey defined torsion-free derived series of groups and proved an injectivity theorem on the associated torsion-free quotients. We show that there is a unive…