Simon Thomas
On the Number of Universal Sofic Groups
The paper is published: Proc. Amer. Math. Soc. 138, no. 7 (2010) 2585-2590

MSC:

03C20 Ultraproducts and related constructions

03E35 Consistency and independence results

20F32 Geometric group theory, See also {05C25, 20Exx, 20Gxx}

Abstract: If $CH$ fails, then there exist $2^{2^{\aleph_{0}}}$ universal sofic groups up to isomorphism.

Keywords: Ultraproducts, expander graphs, sofic groups