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Bibliographic Details
Main Authors: Bonetto, Federico, Popa, Anthony, Powell, Matthew, Chen, Peter, Tung, Steven
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2512.13166
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author Bonetto, Federico
Popa, Anthony
Powell, Matthew
Chen, Peter
Tung, Steven
author_facet Bonetto, Federico
Popa, Anthony
Powell, Matthew
Chen, Peter
Tung, Steven
contents In this paper, we study a system of $M$ particles interacting with a reservoir of $N$ particles, where $N >> M$, and compare this setup to one where the $M$-particle system interacts with a thermostat of infinite particles. Our goal is to prove a suitable upper bound, uniform in time, on the distance between the states of these two setups, given an initial Maxwellian state for both the reservoir and thermostat. Previous work has analyzed this problem using the one-dimensional Kac Model of gas collisions and an $L^2$ norm to define distance; the result was a bound which scaled with $M/\sqrt{N}$. In this paper, we use the $L^2$ norm and the three-dimensional generalization of the Kac Model to prove a bound whose long-term behavior scales with $M/N$.
format Preprint
id arxiv_https___arxiv_org_abs_2512_13166
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Improved Approximation of Infinite Thermostat by Finite Reservoir Using the 3D Kac Model
Bonetto, Federico
Popa, Anthony
Powell, Matthew
Chen, Peter
Tung, Steven
Mathematical Physics
Probability
In this paper, we study a system of $M$ particles interacting with a reservoir of $N$ particles, where $N >> M$, and compare this setup to one where the $M$-particle system interacts with a thermostat of infinite particles. Our goal is to prove a suitable upper bound, uniform in time, on the distance between the states of these two setups, given an initial Maxwellian state for both the reservoir and thermostat. Previous work has analyzed this problem using the one-dimensional Kac Model of gas collisions and an $L^2$ norm to define distance; the result was a bound which scaled with $M/\sqrt{N}$. In this paper, we use the $L^2$ norm and the three-dimensional generalization of the Kac Model to prove a bound whose long-term behavior scales with $M/N$.
title Improved Approximation of Infinite Thermostat by Finite Reservoir Using the 3D Kac Model
topic Mathematical Physics
Probability
url https://arxiv.org/abs/2512.13166