Machine Learning Regularized Solution of the Lippmann-Schwinger Equation

The Lippmann-Schwinger equation has been applied on various branches of physics, especially optical and quantum scattering. Solving the equation requires the inversion of a linear operator specified by the scattering potential, which is ill-conditioned. To resolve numerical difficulty originating fr...

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Bibliographic Details
Main Author: Pang, Subeen
Other Authors: Barbastathis, George
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/140153
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author Pang, Subeen
author2 Barbastathis, George
author_facet Barbastathis, George
Pang, Subeen
author_sort Pang, Subeen
collection MIT
description The Lippmann-Schwinger equation has been applied on various branches of physics, especially optical and quantum scattering. Solving the equation requires the inversion of a linear operator specified by the scattering potential, which is ill-conditioned. To resolve numerical difficulty originating from such ill-conditionedness, we propose a machine learning approach to find an appropriate regularization. Inspired by the proximal algorithm, we try to solve the equation with a hybridization of the physical operator and a regularizing network: a recurrent neural network with long short-term memory (LSTM). We train the LSTM using typical scattering potentials and their corresponding scattered fields. For the evaluation of the LSTM, two scattering cases are considered: electromagnetic scattering by dielectric objects, and electron scattering by multiple screened Coulomb potentials. It is observed that the network can estimate scattered fields that are comparable to those from linear solvers with fewer iterations. We also observed surprising generalization ability. Specifically, in the electromagnetic case, the LSTM trained with objects consisting of dielectric spheres can estimate reasonable solutions for general topologically similar objects, such as polygons. This suggests that the scattering physics is properly fused to the network through the training process.
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spelling mit-1721.1/1401532022-02-08T03:30:13Z Machine Learning Regularized Solution of the Lippmann-Schwinger Equation Pang, Subeen Barbastathis, George Massachusetts Institute of Technology. Department of Mechanical Engineering The Lippmann-Schwinger equation has been applied on various branches of physics, especially optical and quantum scattering. Solving the equation requires the inversion of a linear operator specified by the scattering potential, which is ill-conditioned. To resolve numerical difficulty originating from such ill-conditionedness, we propose a machine learning approach to find an appropriate regularization. Inspired by the proximal algorithm, we try to solve the equation with a hybridization of the physical operator and a regularizing network: a recurrent neural network with long short-term memory (LSTM). We train the LSTM using typical scattering potentials and their corresponding scattered fields. For the evaluation of the LSTM, two scattering cases are considered: electromagnetic scattering by dielectric objects, and electron scattering by multiple screened Coulomb potentials. It is observed that the network can estimate scattered fields that are comparable to those from linear solvers with fewer iterations. We also observed surprising generalization ability. Specifically, in the electromagnetic case, the LSTM trained with objects consisting of dielectric spheres can estimate reasonable solutions for general topologically similar objects, such as polygons. This suggests that the scattering physics is properly fused to the network through the training process. S.M. 2022-02-07T15:27:16Z 2022-02-07T15:27:16Z 2021-09 2021-09-30T17:31:34.768Z Thesis https://hdl.handle.net/1721.1/140153 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Pang, Subeen
Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title_full Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title_fullStr Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title_full_unstemmed Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title_short Machine Learning Regularized Solution of the Lippmann-Schwinger Equation
title_sort machine learning regularized solution of the lippmann schwinger equation
url https://hdl.handle.net/1721.1/140153
work_keys_str_mv AT pangsubeen machinelearningregularizedsolutionofthelippmannschwingerequation