Maruyoshi-Song flows and defect groups of $$ {\mathrm{D}}_{\mathrm{p}}^{\mathrm{b}} $$(G) theories

We study the defect groups of $$ {D}_p^b $$ D p b (G) theories using geometric engineering and BPS quivers. In the simple case when b = h∨(G), we use the BPS quivers of the theory to see that the defect group is compatible with a known Maruyoshi-Song flow. To extend to the case where b ≠ h∨(G), we use a similar Maruyoshi-Song flow to conjecture that the defect groups of $$ {D}_p^b $$ D p b (G) theories are given by those of G(b)[k] theories. In the cases of G = An, E6, E8 we cross check our result by calculating the BPS quivers of the G(b)[k] theories and looking at the cokernel of their intersection matrix.