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We investigate the inverse source problem for the wave equation, arising in photo- and thermoacoustic tomography. There exist quite a few theoretically exact inversion formulas explicitly expressing solution of this problem in terms of the…

Analysis of PDEs · Mathematics 2018-08-01 Ngoc Do , Leonid Kunyansky

We develop an inversion technique of annual scattered light curves to sketch a two-dimensional albedo map of exoplanets in face-on orbits. As a test-bed for future observations of extrasolar terrestrial planets, we apply this mapping…

Earth and Planetary Astrophysics · Physics 2011-09-16 Hajime Kawahara , Yuka Fujii

The obliquity of a terrestrial planet is an important clue about its formation and critical to its climate. Previous studies using simulated photometry of Earth show that continuous observations over most of a planet's orbit can be inverted…

Earth and Planetary Astrophysics · Physics 2018-03-02 Joel C. Schwartz , Clara Sekowski , Hal M. Haggard , Eric Pallé , Nicolas B. Cowan

Many modern applications of Bayesian inference, such as in cosmology, are based on complicated forward models with high-dimensional parameter spaces. This considerably limits the sampling of posterior distributions conditioned on observed…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Marco Raveri , Cyrille Doux , Shivam Pandey

A rigorous mathematical model and an efficient computational method are proposed to solving the inverse elastic surface scattering problem which arises from the near-field imaging of periodic structures. We demonstrate how an enhanced…

Analysis of PDEs · Mathematics 2017-12-08 Huaian Diao , Peijun Li , Xiaokai Yuan

In ill-posed inverse problems, it is commonly desirable to obtain insight into the full spectrum of plausible solutions, rather than extracting only a single reconstruction. Information about the plausible solutions and their likelihoods is…

Computer Vision and Pattern Recognition · Computer Science 2024-05-14 Omer Yair , Elias Nehme , Tomer Michaeli

The use of the tensor virial theorem (TVT) as a diagnostic of anisotropic velocity distributions in galaxies is revisited. The TVT provides a rigorous global link between velocity anisotropy, rotation and shape, but the quantities appearing…

Astrophysics · Physics 2009-11-11 James Binney

By the use of Green's second integral identity we determine the field scattered from a two-dimensional randomly rough isotropic or anisotropic Dirichlet or Neumann surface when it is illuminated by a scalar Gaussian beam. The integral…

We study the inverse problem of recovering the order and the diffusion coefficient of an elliptic fractional partial differential equation from a finite number of noisy observations of the solution. We work in a Bayesian framework and show…

Analysis of PDEs · Mathematics 2017-06-28 Nicolas Garcia Trillos , Daniel Sanz-Alonso

The inverse problem of fractional Brownian motion and other Gaussian processes with stationary increments involves inverting an infinite hermitian positively definite Toeplitz matrix (a matrix that has equal elements along its diagonals).…

Probability · Mathematics 2021-07-09 Safari , Mukeru , Mmboniseni P , Mulaudzi

If an extended source, such as a galaxy, is gravitationally lensed by a massive object in the foreground, the lensing distorts the observed image. It is straightforward to simulate what the observed image would be for a particular lens and…

Astrophysics · Physics 2009-11-13 Brendon J. Brewer , Geraint F. Lewis

Incoherent light is ubiquitous, yet designing optical devices that can handle its random nature is very challenging, since directly averaging over many incoherent incident beams can require a huge number of scattering calculations. We show…

Optics · Physics 2025-04-30 Raphaël Pestourie , Wenjie Yao , Boubacar Kanté , Steven G. Johnson

Toroidal structures are a common feature in a wide variety of astrophysical objects, including dusty tori in AGNs, rings in galaxies, protoplanetary disks, and others. The matter distribution in such structures is not homogeneous and can be…

Astrophysics of Galaxies · Physics 2025-01-22 Elena Bannikova , Serhii Skolota , Massimo Capaccioli

An algorithm is developed and tested for the problem posed by photometric observations of the bulge of the Milky Way. The latter subtends a non-trivial solid angle on the sky, and we show that this permits inversion of the projected…

Astrophysics · Physics 2015-06-24 James Binney , Ortwin Gerhard

This revisit gives a survey on the analytical methods for the inverse exponential Radon transform which has been investigated in the past three decades from both mathematical interests and medical applications such as nuclear medicine…

Image and Video Processing · Electrical Eng. & Systems 2020-02-06 Jason You

We construct axisymmetric and triaxial galaxy models with a phase-space distribution function that depends on linear combinations of the three exact integrals of motion for a separable potential. These Abel models, first introduced by…

Astrophysics · Physics 2009-11-13 G. van de Ven , P. T. de Zeeuw , R. C. E. van den Bosch

Formulating a statistical inverse problem as one of inference in a Bayesian model has great appeal, notably for what this brings in terms of coherence, the interpretability of regularisation penalties, the integration of all uncertainties,…

Statistics Theory · Mathematics 2012-12-19 Natalia A. Bochkina , Peter J. Green

We prove a novel inversion theorem for functionals given as power series in infinite-dimensional spaces and apply it to the inversion of the density-activity relation for inhomogeneous systems. This provides a rigorous framework to prove…

Mathematical Physics · Physics 2019-09-11 Sabine Jansen , Tobias Kuna , Dimitrios Tsagkarogiannis

An exact formulation of the propagation of a monochromatic wave packet impinging upon a transparent, homogeneous, isotropic and parallel slab at oblique incidence is presented. Approximate formulas are derived for low divergence Gaussian…

Optics · Physics 2017-12-18 Michel Lequime , Claude Amra

We propose a Bayesian inference framework to estimate uncertainties in inverse scattering problems. Given the observed data, the forward model and their uncertainties, we find the posterior distribution over a finite parameter field…

Numerical Analysis · Mathematics 2020-11-17 Ana Carpio , Sergei Iakunin , Georg Stadler