On completeness of groups of diffeomorphisms

M Bruveris, FX Vialard - Journal of the European Mathematical Society, 2017 - ems.press
We study completeness properties of the Sobolev diffeomorphism groups Ds (M) endowed
with strong right-invariant Riemannian metrics when M is Rd or a compact manifold without …

Geodesic completeness for Sobolev metrics on the space of immersed plane curves

M Bruveris, PW Michor, D Mumford - Forum of Mathematics, Sigma, 2014 - cambridge.org
We study properties of Sobolev-type metrics on the space of immersed plane curves. We
show that the geodesic equation for Sobolev-type metrics with constant coefficients of order …

[HTML][HTML] Two-component equations modelling water waves with constant vorticity

J Escher, D Henry, B Kolev, T Lyons - Annali di Matematica Pura ed …, 2016 - Springer
In this paper, we derive a two-component system of nonlinear equations which models two-
dimensional shallow water waves with constant vorticity. Then, we prove well-posedness of …

Large-degree asymptotics of rational Painlevé-II functions: noncritical behaviour

RJ Buckingham, PD Miller - Nonlinearity, 2014 - iopscience.iop.org
Rational solutions of the inhomogeneous Painlevé-II equation and of a related coupled
Painlevé-II system have recently arisen in studies of fluid vortices and of the sine-Gordon …

Right-invariant Sobolev metrics of fractional order on the diffeomorphism group of the circle

J Escher, B Kolev - arXiv preprint arXiv:1202.5122, 2012 - arxiv.org
In this paper, we study the geodesic flow of a right-invariant metric induced by a general
Fourier multiplier on the diffeomorphism group of the circle and on some of its homogeneous …

[HTML][HTML] Geometric investigations of a vorticity model equation

M Bauer, B Kolev, SC Preston - Journal of Differential Equations, 2016 - Elsevier
This article consists of a detailed geometric study of the one-dimensional vorticity model
equation ω t+ u ω x+ 2 ω ux= 0, ω= H ux, t∈ R, x∈ S 1, which is a particular case of the …

[HTML][HTML] Local and global well-posedness of the fractional order EPDiff equation on Rd

M Bauer, J Escher, B Kolev - Journal of Differential Equations, 2015 - Elsevier
Of concern is the study of fractional order Sobolev-type metrics on the group of H∞-
diffeomorphism of R d and on its Sobolev completions D q (R d). It is shown that the H s …

A mathematical perspective on density functional perturbation theory

E Cancès, N Mourad - Nonlinearity, 2014 - iopscience.iop.org
This article is concerned with the mathematical analysis of the perturbation method for
extended Kohn–Sham models, in which fractional occupation numbers are allowed. All our …

Objective rates as covariant derivatives on the manifold of Riemannian metrics

B Kolev, R Desmorat - Archive for Rational Mechanics and Analysis, 2024 - Springer
The subject of so-called objective derivatives in Continuum Mechanics has a long history
and has generated varying views concerning their true mathematical interpretation. Several …

[HTML][HTML] Semi-invariant Riemannian metrics in hydrodynamics

M Bauer, K Modin - Calculus of Variations and Partial Differential …, 2020 - Springer
Many models in mathematical physics are given as non-linear partial differential equation of
hydrodynamic type; the incompressible Euler, KdV, and Camassa–Holm equations are well …