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Related papers: Quantitative spectral inequalities for the anisotr…

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In this paper, new spectral inequalities for finite combinations of eigenfunctions of anisotropic Shubin operators are presented. Given a subset $\omega$ and an energy level, we provide an explicit control of the ratio of the L 2 (R d)-norm…

Analysis of PDEs · Mathematics 2022-09-07 Jérémy Martin

We consider the anisotropic Shubin operators $(-\Delta)^m + \vert x\vert^{2k}$ acting on the space $L^2(\mathbb R^n)$, with $k, m \geq1$ some positive integers. We provide sharp quantitative estimates in Gelfand-Shilov spaces for the…

Analysis of PDEs · Mathematics 2023-02-07 Paul Alphonse

We prove time-pointwise quantitative unique continuation estimates for the evolution operators associated to (fractional powers of) the Baouendi--Grushin operators on the cylinder $\mathbb{R}^d \times \mathbb{T}^d$. Corresponding spectral…

Analysis of PDEs · Mathematics 2025-08-13 Paul Alphonse , Albrecht Seelmann

We study the null-controllability of parabolic equations associated to a general class of hypoelliptic quadratic differential operators. Quadratic differential operators are operators defined in the Weyl quantization by complex-valued…

Analysis of PDEs · Mathematics 2017-07-14 Karine Beauchard , Karel Pravda-Starov

This work is devoted to the study of uncertainty principles for finite combinations of Hermite functions. We establish some spectral inequalities for control subsets that are thick with respect to some unbounded densities growing almost…

Analysis of PDEs · Mathematics 2020-10-09 Jérémy Martin , Karel Pravda-Starov

We investigate the null controllability property of the parabolic equation associated with the Grushin operator defined by the canonical almost-Riemannian structure on the 2-dimensional sphere $\mathbb S^2$. This is the natural…

Optimization and Control · Mathematics 2022-05-17 Cyprien Tamekue

We establish a family of uncertainty principles for finite linear combinations of Hermite functions. More precisely, we give a geometric criterion on a subset $S\subset \RR^d$ ensuring that the $L^2$-seminorm associated to $S$ is equivalent…

Analysis of PDEs · Mathematics 2023-03-07 Alexander Dicke , Albrecht Seelmann , Ivan Veselic

In this paper we establish a Lebeau-Robbiano spectral inequality for a degenerated one dimensional elliptic operator and show how it can be used to impulse control and finite time stabilization for a degenerated parabolic equation.…

Analysis of PDEs · Mathematics 2018-03-21 Rémi Buffe , Kim Dang Phung

We study degenerate hypoelliptic Ornstein-Uhlenbeck operators in $L^2$ spaces with respect to invariant measures. The purpose of this article is to show how recent results on general quadratic operators apply to the study of degenerate…

Analysis of PDEs · Mathematics 2014-11-25 Michela Ottobre , Grigorios Pavliotis , Karel Pravda-Starov

Some recent works have shown that the heat equation posed on the whole Euclidean space is null-controllable in any positive time if and only if the control subset is a thick set. This necessary and sufficient condition for…

Analysis of PDEs · Mathematics 2020-10-09 Karine Beauchard , Philippe Jaming , Karel Pravda-Starov

In this paper we establish a Lebeau-Robbiano spectral inequality for a degenerate one dimensional elliptic operator. Carleman techniques and moment method are combined. Application to null controllability on a measurable set in time for the…

Analysis of PDEs · Mathematics 2023-09-28 Rémi Buffe , Kim Dang Phung , Amine Slimani

We prove a spectral inequality (a specific type of uncertainty relation) for Schr\"odinger operators with confinement potentials, in particular of Shubin-type. The sensor sets are allowed to decay exponentially, where the precise allowed…

Analysis of PDEs · Mathematics 2024-07-23 Alexander Dicke , Albrecht Seelmann , Ivan Veselic

We study the null controllability of the parabolic equation associated with the Grushin-type operator $A=\partial_x^2+|x|^{2\gamma}\partial_y^2\,, (\gamma>0),$ in the rectangle $\Omega=(-1,1)\times(0,1)$, under an additive control supported…

Analysis of PDEs · Mathematics 2014-01-29 K. Beauchard , P. Cannarsa , R. Guglielmi

We prove optimal spectral inequalities for Landau operators in full space and in arbitrary dimension. Spectral inequalities are lower bounds on the L 2 -mass of functions in spectral subspaces of finite energy when integrated over a…

Analysis of PDEs · Mathematics 2026-01-06 Sedef Özcan , Matthias Täufer

We study asymptotic behavior in a class of non-autonomous second order parabolic equations with time periodic unbounded coefficients in $\mathbb R\times \mathbb R^d$. Our results generalize and improve asymptotic behavior results for Markov…

Analysis of PDEs · Mathematics 2009-08-11 L. Lorenzi , A. Lunardi , A. Zamboni

We prove some general Sobolev-type and related inequalities for positive operators A of given ultracontractive spectral decay, without assuming e^{-tA} is submarkovian. These inequalities hold on functions, or pure states, as usual, but…

Functional Analysis · Mathematics 2011-02-11 Michel Rumin

We derive new results on the characterization of Gelfand--Shilov spaces $\mathcal{S}^\mu_\nu (\R^n)$, $\mu,\nu >0$, $\mu+\nu \geq 1$ by Gevrey estimates of the $L^2$ norms of iterates of $(m,k)$ anisotropic globally elliptic Shubin (or…

Functional Analysis · Mathematics 2016-09-21 Marco Cappiello , Todor Gramchev , Stevan Pilipovic , Luigi Rodino

We study the partial Gelfand-Shilov regularizing effect and the exponential decay for the solutions to evolution equations associated to a class of accretive non-selfadjoint quadratic operators, which fail to be globally hypoelliptic on the…

Analysis of PDEs · Mathematics 2019-09-04 Paul Alphonse

We study a concentration inequality for eigenfunctions of a Baouendi-Grushin operator on a cylinder or a torus. Using separation of variables, we prove that this inequality holds under a spectral multiplicity condition. Using…

Spectral Theory · Mathematics 2023-12-08 Mohammad Harakeh , Luc Hillairet

We establish inequalities for the eigenvalues of Schr\"odinger operators on compact submanifolds (possibly with nonempty boundary) of Euclidean spaces, of spheres, and of real, complex and quaternionic projective spaces, which are related…

Metric Geometry · Mathematics 2009-09-01 Ahmad El Soufi , Evans Harrell , Said Ilias
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