Results 1 to 10 of about 61,301 (268)
The power of perturbation theory [PDF]
Journal of High Energy Physics, 2017 We study quantum mechanical systems with a discrete spectrum. We show that the asymptotic series associated to certain paths of steepest-descent (Lefschetz thimbles) are Borel resummable to the full result.
Marco Serone +2 more
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Perturbation-adapted perturbation theory [PDF]
The Journal of Chemical Physics, 2022 A new general approach is introduced for defining an optimum zero-order Hamiltonian for Rayleigh–Schrödinger perturbation theory. Instead of taking the operator directly from a model problem, it is constructed to be a best fit to the exact Hamiltonian within any desired functional form.
openaire +4 more sources
Dilaton chiral perturbation theory and applications [PDF]
EPJ Web of Conferences, 2022 We review dilaton chiral perturbation theory (dChPT), the effective low-energy theory for the light sector of near-conformal, confining theories. dChPT provides a systematic expansion in both the fermion mass and the distance to the conformal window.
Golterman Maarten, Shamir Yigal
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Flow-oriented perturbation theory
Journal of High Energy Physics, 2023 We introduce a new diagrammatic approach to perturbative quantum field theory, which we call flow-oriented perturbation theory (FOPT). Within it, Feynman graphs are replaced by strongly connected directed graphs (digraphs).
Michael Borinsky +3 more
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Perturbation theory with quantum signal processing [PDF]
Quantum, 2023 Perturbation theory is an important technique for reducing computational cost and providing physical insights in simulating quantum systems with classical computers.
Kosuke Mitarai +2 more
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The heuristically-based generalized perturbation theory
EPJ Nuclear Sciences & Technologies, 2021 The generalized perturbation method is described relevant to ratios of bi-linear functionals of the real and adjoint neutron fluxes of critical multiplying systems.
Gandini Augusto
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D-instanton perturbation theory
Journal of High Energy Physics, 2020 D-instanton world-volume theory has open string zero modes describing collective coordinates of the instanton. The usual perturbative amplitudes in the D-instanton background suffer from infra-red divergences due to the presence of these zero modes, and ...
Ashoke Sen
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European Physical Journal C: Particles and Fields, 2020 Integral equations for meson–baryon scattering amplitudes are obtained by utilizing time-ordered perturbation theory for a manifestly Lorentz-invariant formulation of baryon chiral perturbation theory.
X.-L. Ren +3 more
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Chiral perturbation theory for GR
Journal of High Energy Physics, 2020 We describe a new perturbation theory for General Relativity, with the chiral first-order Einstein-Cartan action as the starting point. Our main result is a new gauge-fixing procedure that eliminates the connection-to-connection propagator.
Kirill Krasnov, Yuri Shtanov
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The perturbation theory of matrix mechanics based on its canonical transformations
Results in Physics, 2022 We elucidate that the canonical transformations of matrix mechanics are just the transformations of different representations of the standard quantum mechanics, reproduce the non-degenerate, degenerate and time-dependent perturbation theory in three men ...
Yong-Yi Huang
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