Bootstrapping conformal QED$_3$ and deconfined quantum critical point

Abstract: We bootstrap the deconfined quantum critical point (DQCP) and 3D Quantum Electrodynamics (QED$_3$) coupled to $N_f$ flavors of two-component Dirac fermions. We show the lattice and perturbative results on the $SO(5)$ symmetric DQCP are excluded by the bootstrap bounds combined with an irrelevant condition of the lowest singlet scalar. Remarkably, we discover a new family of kinks in the 3D $SO(N)$ vector bootstrap bounds with $N\geqslant6$. We demonstrate bound coincidences between $SU(N_f)$ adjoint and $SO(N_f^2-1)$ vector bootstrap which result from a novel algebraic relation between their crossing equations. By introducing gap assumptions breaking the $SO(N_f^2-1)$ symmetry, the $SU(N_f)$ adjoint bootstrap bounds with large $N_f$ converge to the $1/N_f$ perturbative results of QED$_3$. Our results provide strong evidence that the $SO(5)$ DQCP is not continuous and the critical flavor number of QED$_3$ is slightly above $2$: $N_f^*\in(2,4)$. Bootstrap results near $N_f^*$ are well consistent with the merger and annihilation mechanism for the loss of conformality in QED$_3$.