Salvato in:
Dettagli Bibliografici
Autore principale: Mounaix, Philippe
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:https://arxiv.org/abs/2402.09986
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917848170889216
author Mounaix, Philippe
author_facet Mounaix, Philippe
contents The validity of the instanton analysis approach is tested numerically in the case of the diffraction-amplification problem $\partial_zψ-\frac{i}{2m}\partial^2_{x^2} ψ=g\vert S\vert^2\, ψ$ for $\ln U\gg 1$, where $U=\vertψ(0,L)\vert^2$. Here, $S(x,z)$ is a complex Gaussian random field, $z$ and $x$ respectively are the axial and transverse coordinates, with $0\le z\le L$, and both $m\ne 0$ and $g>0$ are real parameters. We consider a class of $S$, called the `one-max class', for which we devise a specific biased sampling procedure. As an application, $p(U)$, the probability distribution of $U$, is obtained down to values less than $10^{-2270}$ in the far right tail. We find that the agreement of our numerical results with the instanton analysis predictions in Mounaix (2023 {\it J. Phys. A: Math. Theor.} {\bf 56} 305001) is remarkable. Both the predicted algebraic tail of $p(U)$ and concentration of the realizations of $S$ onto the leading instanton are clearly confirmed, which validates the instanton analysis numerically in the large $\ln U$ limit for $S$ in the one-max class.
format Preprint
id arxiv_https___arxiv_org_abs_2402_09986
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Testing the Instanton Approach to the Large Amplification Limit of a Diffraction-Amplification Problem
Mounaix, Philippe
Statistical Mechanics
The validity of the instanton analysis approach is tested numerically in the case of the diffraction-amplification problem $\partial_zψ-\frac{i}{2m}\partial^2_{x^2} ψ=g\vert S\vert^2\, ψ$ for $\ln U\gg 1$, where $U=\vertψ(0,L)\vert^2$. Here, $S(x,z)$ is a complex Gaussian random field, $z$ and $x$ respectively are the axial and transverse coordinates, with $0\le z\le L$, and both $m\ne 0$ and $g>0$ are real parameters. We consider a class of $S$, called the `one-max class', for which we devise a specific biased sampling procedure. As an application, $p(U)$, the probability distribution of $U$, is obtained down to values less than $10^{-2270}$ in the far right tail. We find that the agreement of our numerical results with the instanton analysis predictions in Mounaix (2023 {\it J. Phys. A: Math. Theor.} {\bf 56} 305001) is remarkable. Both the predicted algebraic tail of $p(U)$ and concentration of the realizations of $S$ onto the leading instanton are clearly confirmed, which validates the instanton analysis numerically in the large $\ln U$ limit for $S$ in the one-max class.
title Testing the Instanton Approach to the Large Amplification Limit of a Diffraction-Amplification Problem
topic Statistical Mechanics
url https://arxiv.org/abs/2402.09986