Title: Spacetime symmetries and conformal data in the continuous multi-scale entanglement renormalization ansatz,
Abstract: The generalization of the multi-scale entanglement renormalization ansatz
(MERA) to continuous systems, or cMERA [Haegeman et al., Phys. Rev. Lett, 110,
100402 (2013)], is expected to become a powerful variational ansatz for the
ground state of strongly interacting quantum field theories. In this paper we
investigate, in the simpler context of Gaussian cMERA for free theories, the
extent to which the cMERA state $|\Psi^\Lambda\rangle$ with finite UV cut-off
$\Lambda$ can capture the spacetime symmetries of the ground state
$|\Psi\rangle$. For a free boson conformal field theory (CFT) in 1+1 dimensions
as a concrete example, we build a quasi-local unitary transformation $V$ that
maps $|\Psi\rangle$ into $|\Psi^\Lambda\rangle$ and show two main results. (i)
Any spacetime symmetry of the ground state $|\Psi\rangle$ is also mapped by $V$
into a spacetime symmetry of the cMERA $|\Psi^\Lambda\rangle$. However, while
in the CFT the stress-energy tensor $T_{\mu\nu}(x)$ (in terms of which all the
spacetime symmetry generators are expressed) is local, the corresponding cMERA
stress-energy tensor $T_{\mu\nu}^{\Lambda}(x) = V T_{\mu\nu}(x) V^{\dagger}$ is
quasi-local. (ii) From the cMERA, we can extract quasi-local scaling operators
$O^{\Lambda}_{\alpha}(x)$ characterized by the exact same scaling dimensions
$\Delta_{\alpha}$, conformal spins $s_{\alpha}$, operator product expansion
coefficients $C_{\alpha\beta\gamma}$, and central charge $c$ as the original
CFT. Finally, we argue that these results should also apply to interacting
theories.