Uniformly Super McDuff II${}_1$ Factors

We introduce and study the family of uniformly super McDuff II${}_1$ factors. This family is shown to be closed under elementary equivalence and also coincides with the family of II${}_1$ factors with the Brown property introduced in arXiv:2004.02293. We show that a certain family of existentially closed factors, the so-called infinitely generic factors, are uniformly super McDuff, thereby improving a recent result of arXiv:2205.07442. We also show that Popa’s family of strongly McDuff II${}_1$ factors are uniformly super McDuff. Lastly, we investigate when finitely generic II${}_1$ factors are uniformly super McDuff.