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Main Authors: Romito, Marco, Roveri, Leonardo
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2510.27331
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author Romito, Marco
Roveri, Leonardo
author_facet Romito, Marco
Roveri, Leonardo
contents This paper investigates enhanced dissipation for a passive scalar advected by "very rough" horizontal shear flows, described by an advection-diffusion equation on the 2D torus. The authors extend results of Galeati and Gubinelli (2023) to generic flows in negative Besov spaces, proving that the dissipation rate increases to infinity as viscosity vanishes. This is obtained by deriving (non-sharp) upper and lower bounds on the dissipation rate. The upper bound holds for truly irregular velocities, namely those verifying a suitable version of the Wei irregularity index (Wei (2021)). As a by-product, it follows that for truly rough shear flows the vanishing viscosity solution to the corresponding inviscid equation is trivial.
format Preprint
id arxiv_https___arxiv_org_abs_2510_27331
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Instantaneous Total Enhanced Dissipation For Very Rough Shear Flows
Romito, Marco
Roveri, Leonardo
Analysis of PDEs
76F25, 35Q35, 35R05
This paper investigates enhanced dissipation for a passive scalar advected by "very rough" horizontal shear flows, described by an advection-diffusion equation on the 2D torus. The authors extend results of Galeati and Gubinelli (2023) to generic flows in negative Besov spaces, proving that the dissipation rate increases to infinity as viscosity vanishes. This is obtained by deriving (non-sharp) upper and lower bounds on the dissipation rate. The upper bound holds for truly irregular velocities, namely those verifying a suitable version of the Wei irregularity index (Wei (2021)). As a by-product, it follows that for truly rough shear flows the vanishing viscosity solution to the corresponding inviscid equation is trivial.
title Instantaneous Total Enhanced Dissipation For Very Rough Shear Flows
topic Analysis of PDEs
76F25, 35Q35, 35R05
url https://arxiv.org/abs/2510.27331