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Multi-wave inverse problems are indirect imaging methods using the interaction of two different imaging modalities. One brings spatial accuracy, and the other contrast sensitivity. The inversion method typically involve two steps. The first…

Analysis of PDEs · Mathematics 2023-01-05 Yves Capdeboscq , Tianrui Dai

We consider the inverse problem of recovering the magnetic and potential term of a magnetic Schr\"{o}dinger operator on certain compact Riemannian manifolds with boundary from partial Dirichlet and Neumann data on suitable subsets of the…

Analysis of PDEs · Mathematics 2018-10-10 Sombuddha Bhattacharyya

We prove partial regularity of stationary solutions and minimizers $u$ from a set $\Omega\subset \mathbb R^n$ to a Riemannian manifold $N$, for the functional $\int_\Omega F(x,u,|\nabla u|^2) dx$. The integrand $F$ is convex and satisfies…

Differential Geometry · Mathematics 2017-08-21 Zahra Sinaei

We describe a type of n-point function associated to strongly regular vertex operator algebras V and their irreducible modules. Transformation laws with respect to the Jacobi group are developed for 1-point functions. For certain elements…

Quantum Algebra · Mathematics 2015-08-27 Matthew Krauel , Geoffrey Mason

In this article, we study the properties of the geodesic X-ray transform for asymptotically Euclidean or conic Riemannian metrics and show injectivity under non-trapping and no conjugate point assumptions. We also define a notion of lens…

Differential Geometry · Mathematics 2021-02-09 Colin Guillarmou , Matti Lassas , Leo Tzou

We study the microlocal properties of the geodesic X-ray transform $\mathcal{X}$ on a manifold with boundary allowing the presence of conjugate points. Assuming that there are no self-intersecting geodesics and all conjugate pairs are…

Differential Geometry · Mathematics 2015-02-24 Sean Holman , Gunther Uhlmann

In this article, we propose a non-parametric Bayesian level-set method for simultaneous reconstruction of two different piecewise constant coefficients in an elliptic partial differential equation. We show that the Bayesian formulation of…

Applications · Statistics 2025-05-28 Anuj Abhishek , Thilo Strauss , Taufiquar Khan

In this paper, we consider the problem of reconstructing piecewise smooth functions to high accuracy from nonuniform samples of their Fourier transform. We use the framework of nonuniform generalized sampling (NUGS) to do this, and to…

Numerical Analysis · Mathematics 2014-10-02 Ben Adcock , Milana Gataric , Anders C. Hansen

We consider the problem to reconstruct a wave speed $c \in C^\infty(M)$ in a domain $M \subset \R^n$ from acoustic boundary measurements modelled by the hyperbolic Dirichlet-to-Neumann map $\Lambda$. We introduce a reconstruction formula…

Analysis of PDEs · Mathematics 2012-10-04 Shitao Liu , Lauri Oksanen

We derive nonlinear stability results for numerical integrators on Riemannian manifolds, by imposing conditions on the ODE vector field and the step size that makes the numerical solution non-expansive whenever the exact solution is…

Numerical Analysis · Mathematics 2026-02-10 Marta Ghirardelli , Brynjulf Owren , Elena Celledoni

We address the question of whether a Riemannian manifold-with-boundary (M,g) in dimension two is uniquely determined from knowledge of the distances between points on its boundary. An affirmative answer is called boundary rigidity for…

Differential Geometry · Mathematics 2026-01-08 Spyros Alexakis , Matti Lassas

Let $g$ be a Riemannian metric for $\mathbf{R}^d$ ($d\geq 3$) which differs from the Euclidean metric only in a smooth and strictly convex bounded domain $M$. The lens rigidity problem is concerned with recovering the metric $g$ inside $M$…

Differential Geometry · Mathematics 2017-02-28 Gang Bao , Hai Zhang

In photoacoustic imaging the objective is to determine the optical properties of biological tissue from boundary measurement of the generated acoustic wave. Here, we propose a restriction to piecewise constant media parameters. Precisely we…

Analysis of PDEs · Mathematics 2024-07-09 Yavar Kian , Faouzi Triki

The inverse problem of X-tray transforms considers reconstructing functions from some data that are easier to measure, which is typically the integral of that function along geodesics. We prove that if the domain has a foliation structure,…

Analysis of PDEs · Mathematics 2024-12-11 Qiuye Jia

We consider the inverse problem of recovering a connection on a complex vector bundle over a compact smooth Riemannian manifold with boundary from a Dirichlet-to-Neumann (DN) map at a high fixed frequency. We construct Gaussian beams using…

Analysis of PDEs · Mathematics 2024-04-11 Simon St-Amant

The purpose of this paper is to discuss the relationship between commutative and non-commutative integrability of Hamiltonian systems and to construct new examples of integrable geodesic flows on Riemannian manifolds. In particular, we…

Mathematical Physics · Physics 2007-05-23 Alexey V. Bolsinov , Bozidar Jovanovic

We consider reconstruction of a manifold, or, invariant manifold learning, where a smooth Riemannian manifold $M$ is determined from intrinsic distances (that is, geodesic distances) of points in a discrete subset of $M$. In the studied…

Probability · Mathematics 2019-05-20 Charles Fefferman , Sergei Ivanov , Matti Lassas , Hariharan Narayanan

We prove some Liouville-type theorems for positive harmonic functions on compact Riemannian manifolds with nonnegative Ricci curvature and strictly convex boundary, thereby confirming some cases of Wang's conjecture (J. Geom. Anal. 31,…

Analysis of PDEs · Mathematics 2026-04-23 Xiaohan Cai

The vector-matrix Riemann boundary value problem for the unit disk with piecewise constant matrix is constructively solved by a method of functional equations. By functional equations we mean iterative functional equations with shifts…

Complex Variables · Mathematics 2019-04-16 Vladimir V. Mityushev

We show how an operation of inf-convolution can be used to approximate convex functions with $C^{1}$ smooth convex functions on Riemannian manifolds with nonpositive curvature (in a manner that not only is explicit but also preserves some…

Differential Geometry · Mathematics 2007-05-23 Daniel Azagra , Juan Ferrera