Accuracy of ghost rotationally invariant slave-boson and dynamical mean field theory as a function of the impurity-model bath size

We compare the accuracy of ghost rotationally invariant slave-boson (g-RISB) theory and dynamical mean field (DMFT) on single-band Hubbard model, as a function number bath sites in embedding impurity Hamiltonian. Our benchmark calculations confirm that g-RISB can be systematically improved by increasing sites, similar to DMFT. With few we observe is more accurate than DMFT for ground-state observables. On other hand, relative these methods generally comparable quasiparticle weight spectral function. As expected, satisfies variational principle infinite dimensions, total energy decreases monotonically towards exact value suggesting wave may approach ground state dimensions. results suggest promising method first-principles simulations strongly correlated matter, which capture behavior both static observables, at relatively low computational cost.