Grigori Avramidi

collaborators

2 papers

math.GT2021

Fungible obstructions to embedding 2-complexes

Grigori Avramidi, T. Tam Nguyen Phan

We give examples of finite, simplicial $2$ -complexes that do not PL embed in $R^{4}$ and exhibit, for each such complex, a family of PL immersions into $R^{4}$ that h…

math.GT2021

Division in group rings of surface groups

Grigori Avramidi

We prove a division algorithm for group rings of high genus surface groups and use it to show that some $2$ -complexes with surface fundamental groups are standard. We also give an…