Publications

• Pré-publication, Document de travail

Degenerate/singular beam-type equations: a controllability result

Akil Mohammad, Fragnelli Genni, Sbai Amine

The paper deals with the controllability of a degenerate/singular beam-type equation in divergence or in non-divergence form. In particular, we assume that the degeneracy and the singularity are at the same boundary point and we consider a suitable control $f$ localized on the non degenerate…

2025. ⟨hal-04901715⟩

• Article dans une revue

How Null Vector Performs in a Rational Bézier Curve with Mass Points

Lionel Garnier, Jean-Paul Bécar, Laurent Fuchs

This article points out the kinematics in tracing a Bézier curve defined by control mass points. A mass point is a point with a non-positive weight, a non-negative weight or a vector with a null weight. For any Bézier curve, the speeds at endpoints can be modified at the same time for both…

geometry, 2025, 2 (1), pp.1-35. ⟨10.3390/geometry2010001⟩. ⟨hal-04901396⟩

• Pré-publication, Document de travail

Anderson localization in high-contrast media with random spherical inclusions

Matteo Capoferri, Matthias Täufer

We study spectral properties of partial differential operators modelling composite materials with highly contrasting constituents, comprised of soft spherical inclusions with random radii dispersed in a stiff matrix. Such operators have recently attracted significant interest from the research…

2026. ⟨hal-05663978⟩

• Article dans une revue

Thick trace at infinity for the Hyperbolic Radial Spanning Tree

David Coupier, Lucas Flammant, Viet Chi Tran

Since the works of Howard & Newman (2001), it is known that in straight radial rooted trees, with probability 1, infinite paths all have an asymptotic direction and each asymptotic direction is reached by (at least) an infinite path. Moreover, there exists a set of 'exceptionnal'…

Annales de l'Institut Henri Poincaré (B) Probabilités et Statistiques, 2025. ⟨hal-03928226⟩

• Article dans une revue

Goal-oriented error estimation based on equilibrated flux reconstruction for the approximation of the harmonic formulations in eddy current problems

Emmanuel Creusé, Serge Nicaise, Zuqi Tang

In this work, we propose an a posteriori goal-oriented error estimator for the harmonic A/Phi formulation arising in the modeling of eddy current problems, approximated by nonconforming finite element methods. It is based on the resolution of an adjoint problem associated with the initial one. For…

IMA Journal of Numerical Analysis, 2025, 45 (1), pp.126-162. ⟨10.1093/imanum/drad107⟩. ⟨hal-03954215v2⟩

• Article dans une revue

MAGNETIC BERNSTEIN INEQUALITIES AND SPECTRAL INEQUALITY ON THICK SETS FOR THE LANDAU OPERATOR

Paul Pfeiffer, Matthias Täufer

<div><p>We prove a spectral inequality for the Landau operator. This means that for all f in the spectral subspace corresponding to energies up to E, the L 2 -integral over suitable S ⊂ R 2 can be lower bounded by an explicit constant times the L 2 -norm of f itself. We identify the…

SIAM Journal on Control and Optimization, 2025, 63 (4), pp.2659-2685. ⟨10.1137/24M1681744⟩. ⟨hal-05033935⟩

• Article dans une revue

Covariance parameter estimation of Gaussian processes with approximated functional inputs

Lucas Reding, Andrés F. López-Lopera, François Bachoc

Journal of Multivariate Analysis, 2025, 205, pp.105380. ⟨10.1016/j.jmva.2024.105380⟩. ⟨hal-04844122⟩

• Article dans une revue

Faber-Krahn inequality for the heat content on quantum graphs via random walk expansion

Patrizio Bifulco, Matthias Täufer

We study the heat content on quantum graphs and investigate whether an analogon of the Rayleigh-Faber-Krahn inequality holds. This means that heat content at time $T$ among graphs of equal volume would be maximized by intervals (the graph analogon of balls as in the classic Rayleigh-Faber-Krahn…

Electronic Journal of Probability, 2025, 30 (none), ⟨10.48550/arXiv.2501.09693⟩. ⟨hal-05138408⟩

• Article dans une revue

Method for Connection of Two G2 Data Sets by the Use of a Quintic Rational Bézier Curve Defined with Mass Control Points

Lionel Garnier, Jean-Paul Bécar, Laurent Fuchs

<div><p>The paper deals with the G 2 continuity or planar curves. The G 2 continuity is considered as a superior quality o curvature, which is oten sought ater in high-precision designs and industrial applications. It ensures a perectly smooth transition between dierent parts o a…

WSEAS Transactions on Mathematics, 2024, 23, pp.948 - 961. ⟨10.37394/23206.2024.23.98⟩. ⟨hal-04917172⟩

• Pré-publication, Document de travail

SPECTRUM ANALYSIS OF THE UNDERLYING OPERATOR FOR A 2D PIEZOELECTRIC BEAM WITH MAGNETIC EFFECT ON AN ANNULAR DOMAIN, SECOND VERSION

Virginie Régnier, Mohammad Akil

The aim is to determine the eigenvalues of locally coupled equations modelling a 2D piezoelectric beam with magnetic effect with only one local viscous damping on an annular domain without geometric conditions. The eigenvalues are proved to lie in a vertical band defined explicitly in terms of the…

2024. ⟨hal-04842101⟩