activity
20192026
most citedThe Calderón problem for the fractional wave equation: Uniqueness and optimal stability

23 citations · 70 across the 19 of their papers we have counts for

collaborators

21 papers

math.AP2026

On elastic scattering behavior of corner domains

Pu-Zhao Kow, Mikko Salo, Henrik Shahgholian

We investigate the scattering of elastic waves by anisotropic inhomogeneous media at a fixed wave number. We prove that, in two dimensions, every penetrable obstacle with piecewise…

math.AP2026

Multiphase quadrature domains (existence and uniqueness)

Pu-Zhao Kow, Henrik Shahgholian, Tomas Sjödin

The primary goal of this paper is to give a precise definition and prove existence and uniqueness of multiphase quadrature domains for subharmonic functions, ensuring that the pres…

math.AP2026

Inverse problems for the spectral fractional Laplacian with inhomogeneous Dirichlet boundary data

Ravi Shankar Jaiswal, Pu-Zhao Kow, Suman Kumar Sahoo

In this paper, we study the spectral fractional Laplacian with inhomogeneous Dirichlet boundary data. Our contributions are twofold: first we introduce a Dirichlet-to-Neumann map f…

math.AP2026

Existence and regularity of minimizers for a variational problem of species population density

Pu-Zhao Kow, Masato Kimura, Hiroshi Ohtsuka

We study a variational problem motivated by models of species population density in a nonhomogeneous environment. We first analyze local minimizers and the structure of the saturat…

math.AP2025

On scattering behavior of corner domains with anisotropic inhomogeneities: part II

Pu-Zhao Kow, Mikko Salo, Henrik Shahgholian

We study the scattering behavior of an anisotropic inhomogeneous Lipschitz medium at a fixed wave number, continuing our previous work [SIAM J. Math. Anal., 56(4):4834-4853, 2024]…

math.ST2025

Bayesian inference for the fractional Calderón problem with a single measurement

Pu-Zhao Kow, Janne Nurminen, Jesse Railo

This paper investigates the consistency of a posterior distribution in the single-measurement fractional Calderón problem with additive Gaussian noise. We consider a Bayesian frame…

math.AP2025

An inverse problem for semilinear elliptic equations with generalized Kerr-type nonlinearities

Pu-Zhao Kow, Rulin Kuan

We study the inverse problem of reconstructing the convex hull of unknown inclusions in semilinear elliptic equations with nonanalytic nonlinearities, by extending Ikehata's enclos…

cs.SD2025

A Speech Enhancement Method Using Fast Fourier Transform and Convolutional Autoencoder

Pu-Yun Kow, Pu-Zhao Kow

This paper addresses the reconstruction of audio signals from degraded measurements. We propose a lightweight model that combines the discrete Fourier transform with a Convolutiona…

math.AP2024★ 2 cited

Increasing resolution and instability for linear inverse scattering problems

Pu-Zhao Kow, Mikko Salo, Sen Zou

In this work we study the increasing resolution of linear inverse scattering problems at a large fixed frequency. We consider the problem of recovering the density of a Herglotz wa…

math.AP2024★ 1 cited

Multi-phase -quadrature domains and applications to acoustic waves and magnetic fields

Pu-Zhao Kow, Henrik Shahgholian

The primary objective of this paper is to explore the multi-phase variant of quadrature domains associated with the Helmholtz equation, commonly referred to as -quadrature domai…

math.AP2023★ 8 cited

On scattering behavior of corner domains with anisotropic inhomogeneities

Pu-Zhao Kow, Mikko Salo, Henrik Shahgholian

This paper investigates the possible scattering and non-scattering behavior of an anisotropic and inhomogeneous Lipschitz medium at a fixed wave number and with a single incident f…

math.AP2023★ 2 cited

Unique continuation for the momentum ray transform

Joonas Ilmavirta, Pu-Zhao Kow, Suman Kumar Sahoo

The present article focuses on a unique continuation result for certain weighted ray transforms, utilizing the unique continuation property (UCP) of the fractional Laplace operator…

math.AP2023★ 5 cited

A minimization problem with free boundary and its application to inverse scattering problems

Pu-Zhao Kow, Mikko Salo, Henrik Shahgholian

We study a minimization problem with free boundary, resulting in hybrid quadrature domains for the Helmholtz equation, as well as some application to inverse scattering problem.

math.AP2023★ 3 cited

On positivity sets for Helmholtz solutions

Pu-Zhao Kow, Mikko Salo, Henrik Shahgholian

We address the question of finding global solutions of the Helmholtz equation that are positive in a given set. This question arises in inverse scattering for penetrable obstacles.…

math.AP2022★ 8 cited

Quadrature domains for the Helmholtz equation with applications to non-scattering phenomena

Pu-Zhao Kow, Simon Larson, Mikko Salo +1

In this paper, we introduce quadrature domains for the Helmholtz equation. We show existence results for such domains and implement the so-called partial balayage procedure. We als…

math.AP2022★ 3 cited

An inverse problem for semilinear equations involving the fractional Laplacian

Pu-Zhao Kow, Shiqi Ma, Suman Kumar Sahoo

Our work concerns the study of inverse problems of heat and wave equations involving the fractional Laplacian operator with zeroth order nonlinear perturbations. We recover nonline…

math.AP2021★ 1 cited

Landis-type conjecture for the half-Laplacian

Pu-Zhao Kow, Jenn-Nan Wang

In this paper, we study the Landis-type conjecture, i.e., unique continuation property from infinity, of the fractional Schrödinger equation with drift and potential terms. We show…

math.AP2021★ 23 cited

The Calderón problem for the fractional wave equation: Uniqueness and optimal stability

Pu-Zhao Kow, Yi-Hsuan Lin, Jenn-Nan Wang

We study an inverse problem for the fractional wave equation with a potential by the measurement taking on arbitrary subsets of the exterior in the space-time domain. We are intere…

math.AP2021★ 12 cited

Optimality of increasing stability for an inverse boundary value problem

Pu-Zhao Kow, Gunther Uhlmann, Jenn-Nan Wang

In this work we study the optimality of increasing stability of the inverse boundary value problem (IBVP) for Schrödinger equation. The rigorous justification of increasing stabili…

math.AP2019

The Lewy-Stampacchia Inequality for the Fractional Laplacian and Its Application to Anomalous Unidirectional Diffusion Equations

Pu-Zhao Kow, Masato Kimura

In this paper, we consider a Lewy-Stampacchia-type inequality for the fractional Laplacian on a bounded domain in Euclidean space. Using this inequality, we can show the well-posed…

math.AP2019★ 2 cited

On Landis Conjecture for the Fractional Schrödinger Equation

Pu-Zhao Kow

In this paper, we study a Landis-type conjecture for the general fractional Schrödinger equation . As a byproduct, we also proved the additivity and boundedness of…