Abstract
O(N) xO(2) model of 2N scalar fields in the bifundamental representation of the global symmetry group furnishes an example of a system where unitary fixed points exist not for all N but in a range of N above some N_c(d), where N_c(d) is a rapidly varying function of dimension d. I will describe how N_c(d) can be found using the conformal bootstrap. I will also describe the relation of our work to a contentious issue of "focus fixed points" which has been identified in this model by previous work.
Joint work with Marten Reehorst, Balt van Rees, and Benoit Sirois.