The Analytic Wavefunction

Abstract The wavefunction in quantum field theory is an invaluable tool for tackling a variety of problems, including probing the interior of Minkowski spacetime and modelling boundary observables in de Sitter spacetime. Here we study the analytic structure of wavefunction coefficients in Minkowski...

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Main Authors: Santiago Agüí Salcedo, Mang Hei Gordon Lee, Scott Melville, Enrico Pajer
Format: Article
Language:English
Published: SpringerOpen 2023-06-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP06(2023)020
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author Santiago Agüí Salcedo
Mang Hei Gordon Lee
Scott Melville
Enrico Pajer
author_facet Santiago Agüí Salcedo
Mang Hei Gordon Lee
Scott Melville
Enrico Pajer
author_sort Santiago Agüí Salcedo
collection DOAJ
description Abstract The wavefunction in quantum field theory is an invaluable tool for tackling a variety of problems, including probing the interior of Minkowski spacetime and modelling boundary observables in de Sitter spacetime. Here we study the analytic structure of wavefunction coefficients in Minkowski as a function of their kinematics. We introduce an off-shell wavefunction in terms of amputated time-ordered correlation functions and show that it is analytic in the complex energy plane except for possible singularities on the negative real axis. These singularities are determined to all loop orders by a simple energy-conservation condition. We confirm this picture by developing a Landau analysis of wavefunction loop integrals and corroborate our findings with several explicit calculations in scalar field theories. This analytic structure allows us to derive new UV/IR sum rules for the wavefunction that fix the coefficients in its low-energy expansion in terms of integrals of discontinuities in the corresponding UV-completion. In contrast to the analogous sum rules for scattering amplitudes, the wavefunction sum rules can also constrain total-derivative interactions. We explicitly verify these new relations at one-loop order in simple UV models of a light and a heavy scalar. Our results, which apply to both Lorentz invariant and boost-breaking theories, pave the way towards deriving wavefunction positivity bounds in flat and cosmological spacetimes.
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spelling doaj.art-7688c85daf4c44db9eb899d53f3d99472023-09-24T11:05:54ZengSpringerOpenJournal of High Energy Physics1029-84792023-06-012023619010.1007/JHEP06(2023)020The Analytic WavefunctionSantiago Agüí Salcedo0Mang Hei Gordon Lee1Scott Melville2Enrico Pajer3Department of Applied Mathematics and Theoretical Physics, University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, University of CambridgeAbstract The wavefunction in quantum field theory is an invaluable tool for tackling a variety of problems, including probing the interior of Minkowski spacetime and modelling boundary observables in de Sitter spacetime. Here we study the analytic structure of wavefunction coefficients in Minkowski as a function of their kinematics. We introduce an off-shell wavefunction in terms of amputated time-ordered correlation functions and show that it is analytic in the complex energy plane except for possible singularities on the negative real axis. These singularities are determined to all loop orders by a simple energy-conservation condition. We confirm this picture by developing a Landau analysis of wavefunction loop integrals and corroborate our findings with several explicit calculations in scalar field theories. This analytic structure allows us to derive new UV/IR sum rules for the wavefunction that fix the coefficients in its low-energy expansion in terms of integrals of discontinuities in the corresponding UV-completion. In contrast to the analogous sum rules for scattering amplitudes, the wavefunction sum rules can also constrain total-derivative interactions. We explicitly verify these new relations at one-loop order in simple UV models of a light and a heavy scalar. Our results, which apply to both Lorentz invariant and boost-breaking theories, pave the way towards deriving wavefunction positivity bounds in flat and cosmological spacetimes.https://doi.org/10.1007/JHEP06(2023)020Effective Field TheoriesBoundary Quantum Field TheoryScattering Amplitudes
spellingShingle Santiago Agüí Salcedo
Mang Hei Gordon Lee
Scott Melville
Enrico Pajer
The Analytic Wavefunction
Journal of High Energy Physics
Effective Field Theories
Boundary Quantum Field Theory
Scattering Amplitudes
title The Analytic Wavefunction
title_full The Analytic Wavefunction
title_fullStr The Analytic Wavefunction
title_full_unstemmed The Analytic Wavefunction
title_short The Analytic Wavefunction
title_sort analytic wavefunction
topic Effective Field Theories
Boundary Quantum Field Theory
Scattering Amplitudes
url https://doi.org/10.1007/JHEP06(2023)020
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