Spectral gap for the growth-fragmentation equation via Harris's Theorem

José A. Cañizo (1) , Pierre Gabriel (2) , Havva Yoldaş (3)

1 UGR - Universidad de Granada = University of Granada
2 UVSQ - Université de Versailles Saint-Quentin-en-Yvelines
3 ICJ - Institut Camille Jordan

We study the long-time behaviour of the growth-fragmentation equation, a nonlocal linear evolution equation describing a wide range of phenomena in structured population dynamics. We show the existence of a spectral gap under conditions that generalise those in the literature by using a method based on Harris's theorem, a result coming from the study of equilibration of Markov processes. The difficulty posed by the non-conservativeness of the equation is overcome by performing an $h$-transform, after solving the dual Perron eigenvalue problem. The existence of the direct Perron eigenvector is then a consequence of our methods, which prove exponential contraction of the evolution equation. Moreover the rate of convergence is explicitly quantifiable in terms of the dual eigenfunction and the coefficients of the equation.

Domaines: Mathématiques [math]

José A. Cañizo, Pierre Gabriel, Havva Yoldaş. Spectral gap for the growth-fragmentation equation via Harris's Theorem. 2020. ⟨hal-02973959v1⟩