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Modal based hypocoercivity methods on the torus and the real line with application to Goldstein-Taylor models

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Virtualconference
Authors : Arnold, Anton (Author of the conference)
CIRM (Publisher )

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Abstract : We are concerned with deriving sharp exponential decay estimates (i.e. with maximum rate and minimum multiplicative constant) for linear, hypocoercive evolution equations. Using a modal decomposition of the model allows to assemble a Lyapunov functional using Lyapunov matrix inequalities for each Fourier mode.
We shall illustrate the approach on the 1D Goldstein-Taylor model, a2-velocity transport-relaxation equation. On the torus the lowest Fourier modes determine the spectral gap of the whole equation in $L^{2}$. By contrast, on the whole real line the Goldstein-Taylor model does not have a spectral gap, since the decay rate of the Fourier modes approaches zero in the small mode limit. Hence, the decay is reduced to algebraic.
In the final part of the talk we consider the Goldstein-Taylor model with non-constant relaxation rate, which is hence not amenable to a modal decomposition. In this case we construct a Lyapunov functional of pseudodifferential nature, one that is motivated by the modal analysis in the constant case.The robustness of this approach is illustrated on a multi-velocity GoldsteinTaylor model, yielding explicit rates of convergence to the equilibrium.
This is joint work with J. Dolbeault, A. Einav, C. Schmeiser, B. Signorello, and T. Wöhrer.

Keywords : BGK equation; hypocoercivity; large time behaviour; exponential decay; Lyapunov functional

MSC Codes :
35B40 - Asymptotic behavior of solutions of PDE
35S05 - General theory of $\Psi$DO
82C40 - Kinetic theory of gases
35Q82 - PDEs in connection with statistical mechanics

Additional resources :
https://www.cirm-math.fr/RepOrga/2355/Slides/slide_Anton_ARNOLD.pdf

    Information on the Video

    Film maker : Hennenfent, Guillaume
    Language : English
    Available date : 09/04/2021
    Conference Date : 22/03/2021
    Subseries : Research talks
    arXiv category : Analysis of PDEs
    Mathematical Area(s) : Analysis and its Applications ; PDE
    Format : MP4 (.mp4) - HD
    Video Time : 00:40:31
    Targeted Audience : Researchers
    Download : https://videos.cirm-math.fr/2021-03-22_Arnold.mp4

Information on the Event

Event Title : Jean Morlet Chair 2021- Conference: Kinetic Equations: From Modeling Computation to Analysis / Chaire Jean-Morlet 2021 - Conférence : Equations cinétiques : Modélisation, Simulation et Analyse
Event Organizers : Bostan, Mihaï ; Jin, Shi ; Mehrenberger, Michel ; Montibeller, Celine
Dates : 22/03/2021 - 26/03/2021
Event Year : 2021
Event URL : https://www.chairejeanmorlet.com/2355.html

Citation Data

DOI : 10.24350/CIRM.V.19733203
Cite this video as: Arnold, Anton (2021). Modal based hypocoercivity methods on the torus and the real line with application to Goldstein-Taylor models. CIRM. Audiovisual resource. doi:10.24350/CIRM.V.19733203
URI : http://dx.doi.org/10.24350/CIRM.V.19733203

See Also

Bibliography

  • ARNOLD, Anton, EINAV, Amit, SIGNORELLO, Beatrice, et al. Large time convergence of the non-homogeneous Goldstein-Taylor Equation. Journal of Statistical Physics, 2021, vol. 182, no 2, p. 1-35. - https://doi.org/10.1007/s10955-021-02702-8

  • ARNOLD, Anton, DOLBEAULT, Jean, SCHMEISER, Christian, et al. Sharpening of decay rates in Fourier based hypocoercivity methods. arXiv preprint arXiv:2012.09103, 2020. - https://arxiv.org/abs/2012.09103



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