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arXiv · 2311.18125

Bayesian interpretation of Backus-Gilbert methods

Luigi Del Debbio·Alessandro Lupo·Marco Panero·Nazario Tantalo
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Abstract

The extraction of spectral densities from Euclidean correlators evaluated on the lattice is an important problem, as these quantities encode physical information on scattering amplitudes, finite-volume spectra, inclusive decay rates, and transport coefficients. In this contribution, we show that the Bayesian approach to this "inverse" problem, based on Gaussian processes, can be reformulated in a way that yields a solution equivalent, up to statistical uncertainties, to the one obtained in a Backus-Gilbert approach. After discussing this equivalence, we point out its implications for a reliable determination of spectral densities from lattice simulations.

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Luigi Del Debbio, Alessandro Lupo, Marco Panero, Nazario Tantalo. 2023-11-29. Bayesian interpretation of Backus-Gilbert methods. https://arxiv.org/abs/2311.18125

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