5 papers
Some remarks on Grothendieck pairs
Andrei Jaikin-Zapirain, Alexander Lubotzky
We revisit the paper of Alexander Grothendiek where he introduced Grothendieck pairs and discuss the relation between profinite rigidity and left/right Grothendieck rigidity. We al…
Finite groups and complex projective surfaces
Alexander Lubotzky, Matthew Stover
In response to a question raised by Belolipetsky and the first author, we prove that for every finite group there are infinitely many isomorphism classes of compact complex hyp…
Characteristic Subgroup Growth
Liam Hanany, Alexander Lubotzky
Let denote the number of characteristic subgroups of index at most in a finitely generated group . In response to a question of I. Rivin we show that…
Explicit Lossless Vertex Expanders
Jun-Ting Hsieh, Alexander Lubotzky, Sidhanth Mohanty +2
We give the first construction of explicit constant-degree lossless vertex expanders. Specifically, for any and sufficiently large , we give an explicit constr…
Non-congruence presentations of finite simple groups
William Y. Chen, Alexander Lubotzky, Pham Huu Tiep
We prove two results on some special generators of finite simple groups and use them to prove that every non-abelian finite simple group admits a non-congruence presentation (a…