English

L\'evy processes as weak limits of rough Heston models

Probability 2026-03-31 v2

Abstract

We show weak convergence of the time-tt 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 HH for the model is 12\frac{1}{2} as in [Abi Jaber, & De Carvalho, 2024], or that H12H\searrow -\frac{1}{2} as in [Abi Jaber, Attal, & Rosenbaum, 2025], so the result potentially has increased financial relevance. We later extend the analysis to the case where VV 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 M1M_1 topology.

Keywords

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}
}
R2 v1 2026-07-01T04:58:42.084Z