The attenuated geodesic X-ray transform

TL;DR

This paper investigates the stability of the attenuated geodesic X-ray transform, analyzing how weights and geometry influence stability, and describes artifacts and limitations of reconstruction algorithms in unstable cases.

Contribution

It provides a detailed analysis of stability conditions, artifacts, and the limitations of the Landweber algorithm in the context of the attenuated geodesic X-ray transform.

Findings

Stability depends on the interplay between attenuation weights and geometry.

Unstable cases produce specific artifacts related to conjugate points.

Landweber algorithm fails to reconstruct accurately in unstable scenarios.

Abstract

This article deals with stability issues related to geodesic X-ray transforms, where an interplay between the (attenuation type) weight in the transform and the underlying geometry strongly impact whether the problem is stable or unstable. In the unstable case, we also explain what types of artifacts are expected in terms of the underlying conjugate points and the microlocal weights at those points. We show in particular that the well-known iterative reconstruction Landweber algorithm cannot provide accurate reconstruction when the problem is unstable, though the artifacts generated, specific for the reconstruction algorithm, can be properly described.