General validity of the proposed Sp(k) chiral-ring constraints
Establish that, for every five-dimensional N=1 Sp(k) gauge theory with 0 ≤ N_f ≤ 2k+5 fundamental hypermultiplets that admits a UV fixed point, the Higgs-branch chiral ring at infinite coupling is generated by the mesons M (adjoint of SO(2N_f)), the gaugino bilinear S (moment map of the topological U(1) symmetry), and instanton operators I and \tilde{I} (spinors of SO(2N_f)), and that these generators satisfy the relations M^2_{ij} = S^2 δ_{ij}; (Mγ)·I = SI and (Mγ)·\tilde{I} = S\tilde{I}; ε · ∧^p M = S^a (∧^b M) when N_f ≤ 2k+1 with p = a + b, N_f = p + b, and p ≤ k+1; S^c (∧^d M) = (I·\tilde{I})|_{μ_{2d}} with c + d = k + 1; and Sym^2 I = (I·I)|_{μ_{N_f}^2} (and similarly for \tilde{I}).
References
The following relations have been tested systematically for $Sp(2)$ with $N_f=1\dots9$, and for $SU(2)$ in , as well as in some sporadic cases at higher rank. We conjecture them to appear in general for $Sp(k)$ with any allowed number of flavours.