B. Hind | Searcharxiv

arXiv2026

Hamiltonian-based dimensional reduction and spectral reconstruction with Wilson-Dirac fermions

Motivated by the process of reconstructing real-time spectral functions from Euclidean correlators in lattice QCD, we derive explicit expressions for the fermionic determinant and the propagator of the four-dimensional clover-improved Wilson-Dirac fermions on anisotropic lattices in terms of the three-dimensional Wilson-Dirac Hamiltonian operator. We derive an effective Hamiltonian that governs Euclidean time evolution at finite temporal lattice spacing, and demonstrate its hermiticity and particle-anti-particle symmetry. Our results allow to quantify lattice artifacts of the numerical spectral reconstruction based on Euclidean fermionic correlators at finite temporal lattice spacing.

hep-lat↗

arXiv2025

Spectral reconstruction based on dimensional reduction in high-temperature gauge theories

We propose a numerical spectral reconstruction workflow for high-temperature gauge theories that incorporates elements of semi-classical real-time evolution directly into standard lattice QCD simulations via high-temperature dimensional reduction, thus counteracting the deterioration of Euclidean-time correlators at high temperatures. With a moderate numerical cost, our method allows to estimate spectral functions with parametrically better frequency resolution as compared with spectral reconstruction methods based on Euclidean-time correlators alone. The method is tested on a simple (1+1)-dimensional Abelian gauge theory with fermions, where our method precisely reproduces the full quantum spectral functions calculated using exact numerical diagonalization in the high-temperature, weak-coupling regime. We also demonstrate the feasibility of our approach by applying it to light-quark meson correlators in lattice QCD deep in the deconfinement regime.

hep-lat↗