Proceedings of the American Mathematical Society
In this paper we investigate the 0-concordance classes of 2-knots in S4, an equivalence relation that is related to understanding smooth structures on 4-manifolds. Using Rochlin’s invariant, and invariants arising from Heegaard–Floer homology, we will prove that there are infinitely many 0-concordance classes of 2-knots.
Sunukjian, Nathan, "concordance of 2-knots" (2021). University Faculty Publications. 176.