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Stents are medical devices designed to modify blood flow in aneurysm sacs, in order to prevent their rupture. Some of them can be considered as a locally periodic rough boundary. In order to approximate blood flow in arteries and vessels of…

Analysis of PDEs · Mathematics 2009-01-20 Eric Bonnetier , Didier Bresch , Vuk Milisic

Continuous data assimilation addresses time-dependent problems with unknown initial conditions by incorporating observations of the solution into a nudging term. For the prototypical heat equation with variable conductivity and the Neumann…

Numerical Analysis · Mathematics 2025-04-01 Vladimir Yushutin

This paper is on the construction of structure-preserving, online-efficient reduced models for the barotropic Euler equations with a friction term on networks. The nonlinear flow problem finds broad application in the context of gas…

Numerical Analysis · Mathematics 2021-10-12 Björn Liljegren-Sailer , Nicole Marheineke

Given two continuity equations with density-dependent velocities, we provide a new formula for the Wasserstein distance between the solutions in terms of the difference of velocities evaluated at the same density. The formula is…

Analysis of PDEs · Mathematics 2026-03-27 José A. Carrillo , Piotr Gwiazda , Jakub Skrzeczkowski

We analyse the large--scale velocity field obtained by N--body simulations of cold dark matter (CDM) models with non--Gaussian primordial density fluctuations, considering models with both positive and negative primordial skewness in the…

Astrophysics · Physics 2015-06-24 F. Lucchin , S. Matarrese , A. Messina , L. Moscardini , G. Tormen

Nonlinear gravitational instability is a crucial way to comprehend the clustering of matter and the formation of nonlinear structures in both the Universe and stellar systems. However, with the exception of a few exact particular solutions…

General Relativity and Quantum Cosmology · Physics 2023-07-10 Chao Liu

We consider a system of semilinear partial differential equations (PDEs) with a nonlinearity depending on both the solution and its gradient. The Neumann boundary condition depends on the solution in a nonlinear manner. The uniform…

Probability · Mathematics 2022-01-14 Khaled Bahlali , Brahim Boufoussi , Soufiane Mouchtabih

In this paper, we mainly discuss the convergence behavior of diffuse domain method (DDM) for solving semilinear parabolic equations with Neumann boundary condition defined in general irregular domains. We use a phasefield function to…

Numerical Analysis · Mathematics 2025-10-21 Yuejin Xu

In this work we propose an approximate Minimum Mean-Square Error (MMSE) filter for linear dynamic systems with Gaussian Mixture noise. The proposed estimator tracks each component of the Gaussian Mixture (GM) posterior with an individual…

Systems and Control · Computer Science 2015-06-26 Leila Pishdad , Fabrice Labeau

We consider semilinear hyperbolic systems with a trilinear nonlinearity. Both the differential equation and the initial data contain the inverse of a small parameter $\varepsilon$, and typical solutions oscillate with frequency proportional…

Analysis of PDEs · Mathematics 2022-07-01 Julian Baumstark , Tobias Jahnke

We present a numerical study of the relation between the cosmic peculiar velocity field and the gravitational acceleration field. We show that on mildly non-linear scales (4-10 Mpc Gaussian smoothing), the distribution of the Cartesian…

Accurately estimating data density is crucial for making informed decisions and modeling in various fields. This paper presents a novel nonparametric density estimation procedure that utilizes bivariate penalized spline smoothing over…

Methodology · Statistics 2024-10-29 Kunal Das , Shan Yu , Guannan Wang , Li Wang

This paper studies the numerical methods to approximate the solutions for a sort of McKean-Vlasov neutral stochastic differential delay equations (MV-NSDDEs) that the growth of the drift coefficients is super-linear. First, We obtain that…

Probability · Mathematics 2022-11-04 Yuanping Cui , Xiaoyue Li , Yi Liu , Chenggui Yuan

Non-Gaussian likelihoods are essential for modelling complex real-world observations but pose significant computational challenges in learning and inference. Even with Gaussian priors, non-Gaussian likelihoods often lead to analytically…

Machine Learning · Statistics 2024-10-29 Thang D. Bui

Using third-order perturbation theory, we derive a relation between the mean divergence of the peculiar velocity given density and the density itself. Our calculations assume Gaussian initial conditions and are valid for Gaussian filtering…

Astrophysics · Physics 2015-06-24 Michal Chodorowski , Ewa Lokas , Agnieszka Pollo , Adi Nusser

We show error estimates for a cut finite element approximation of a second order elliptic problem with mixed boundary conditions. The error estimates are of low regularity type where we consider the case when the exact solution $u \in H^s$…

Numerical Analysis · Mathematics 2020-07-07 Erik Burman , Peter Hansbo , Mats G. Larson

It is well-known that non-linear approximation has an advantage over linear schemes in the sense that it provides comparable approximation rates to those of the linear schemes, but to a larger class of approximands. This was established for…

Classical Analysis and ODEs · Mathematics 2010-04-28 Thomas Hangelbroek , Amos Ron

We consider the problem of Bayesian density estimation on the positive semiline for possibly unbounded densities. We propose a hierarchical Bayesian estimator based on the gamma mixture prior which can be viewed as a location mixture. We…

Statistics Theory · Mathematics 2020-02-25 Natalia Bochkina , Judith Rousseau

High-frequency wave propagation is often modelled by nonlinear Friedrichs systems where both the differential equation and the initial data contain the inverse of a small parameter $\varepsilon$, which causes oscillations with wavelengths…

Analysis of PDEs · Mathematics 2024-02-21 Julian Baumstark , Tobias Jahnke

We obtain approximations for the CDM particle trajectories starting from Lagrangian Perturbation Theory. These estimates for the CDM trajectories result in approximations for the density in real and redshift space, as well as for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Svetlin Tassev , Matias Zaldarriaga