Moments, Time-Inversion and Source Identification for the Heat Equation

Fuente: arXiv
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Main Authors: Liu, Kang, Zuazua, Enrique
Format: Preprint
Published: 2025
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_version_ 1866914255237808128
author Liu, Kang
Zuazua, Enrique
author_facet Liu, Kang
Zuazua, Enrique
contents We address the initial source identification problem for the heat equation, a notably ill-posed inverse problem characterized by exponential instability. Departing from classical Tikhonov regularization, we propose a novel approach based on moment analysis of the heat flow, transforming the problem into a more stable inverse moment formulation. By evolving the measured terminal time moments backward through their governing ODE system, we recover the moments of the initial distribution. We then reconstruct the source by solving a convex optimization problem that minimizes the total variation of a measure subject to these moment constraints. This formulation naturally promotes sparsity, yielding atomic solutions that are sums of Dirac measures. Compared to existing methods, our moment-based approach reduces exponential error growth to polynomial growth with respect to the terminal time. We provide explicit error estimates on the recovered initial distributions in terms of moment order, terminal time, and measurement errors. In addition, we develop efficient numerical discretization schemes and demonstrate significant stability improvements of our approach through comprehensive numerical experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02677
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Moments, Time-Inversion and Source Identification for the Heat Equation
Liu, Kang
Zuazua, Enrique
Numerical Analysis
Analysis of PDEs
Optimization and Control
68T07, 68T09, 90C06, 90C26
We address the initial source identification problem for the heat equation, a notably ill-posed inverse problem characterized by exponential instability. Departing from classical Tikhonov regularization, we propose a novel approach based on moment analysis of the heat flow, transforming the problem into a more stable inverse moment formulation. By evolving the measured terminal time moments backward through their governing ODE system, we recover the moments of the initial distribution. We then reconstruct the source by solving a convex optimization problem that minimizes the total variation of a measure subject to these moment constraints. This formulation naturally promotes sparsity, yielding atomic solutions that are sums of Dirac measures. Compared to existing methods, our moment-based approach reduces exponential error growth to polynomial growth with respect to the terminal time. We provide explicit error estimates on the recovered initial distributions in terms of moment order, terminal time, and measurement errors. In addition, we develop efficient numerical discretization schemes and demonstrate significant stability improvements of our approach through comprehensive numerical experiments.
title Moments, Time-Inversion and Source Identification for the Heat Equation
topic Numerical Analysis
Analysis of PDEs
Optimization and Control
68T07, 68T09, 90C06, 90C26
url https://arxiv.org/abs/2507.02677