L\'evy processes as weak limits of rough Heston models
Abstract
We show weak convergence of the time- marginals for the integrated variance in a re-scaled rough Heston model to an Inverse Gaussian L\'{e}vy process. This shows we can obtain such a limit without having to impose that the true Hurst exponent for the model is as in [Abi Jaber, & De Carvalho, 2024], or that as in [Abi Jaber, Attal, & Rosenbaum, 2025], so the result potentially has increased financial relevance. We later extend the analysis to the case where has jumps, showing weak convergence of the finite-dimensional distributions of the integrated variance to a deterministic time-change of the first-passage time process to lower barriers for a more general class of spectrally positive L\'evy processes. This convergence result is then strengthened to a functional setting, namely on the space of c\`adl\`ag functions on the non-negative half-line endowed with the topology.
Cite
@article{arxiv.2508.14835,
title = {L\'evy processes as weak limits of rough Heston models},
author = {Alessandro Bondi and Martin Forde},
journal= {arXiv preprint arXiv:2508.14835},
year = {2026}
}