Rough fractional diffusions as scaling limits of nearly unstable heavy tailed Hawkes processes

Autor: Mathieu Rosenbaum, Thibault Jaisson
Jazyk: angličtina
Rok vydání: 2015
Předmět:
nearly unstable processes
Statistics and Probability
volatility
01 natural sciences
Power law
Point process
FOS: Economics and business
010104 statistics & probability
fractional stochastic equation
60F05
0502 economics and business
FOS: Mathematics
60G22
Statistical physics
Limit (mathematics)
0101 mathematics
Brownian motion
Mathematics
Hurst exponent
Statistical Finance (q-fin.ST)
050208 finance
Quantitative Finance - Trading and Market Microstructure
heavy tail
Probability (math.PR)
05 social sciences
limit theorems
long memory
Quantitative Finance - Statistical Finance
fractional Cox–Ingersoll–Ross process
Trading and Market Microstructure (q-fin.TR)
Cox–Ingersoll–Ross model
Heavy-tailed distribution
Kernel (statistics)
Statistics
Probability and Uncertainty

Hawkes processes
Mathematics - Probability
Zdroj: Ann. Appl. Probab. 26, no. 5 (2016), 2860-2882
Popis: We investigate the asymptotic behavior as time goes to infinity of Hawkes processes whose regression kernel has $L^1$ norm close to one and power law tail of the form $x^{-(1+\alpha)}$, with $\alpha\in(0,1)$. We in particular prove that when $\alpha\in(1/2,1)$, after suitable rescaling, their law converges to that of a kind of integrated fractional Cox-Ingersoll-Ross process, with associated Hurst parameter $H=\alpha-1/2$. This result is in contrast to the case of a regression kernel with light tail, where a classical Brownian CIR process is obtained at the limit. Interestingly, it shows that persistence properties in the point process can lead to an irregular behavior of the limiting process. This theoretical result enables us to give an agent-based foundation to some recent findings about the rough nature of volatility in financial markets.
Comment: 21 pages
Databáze: OpenAIRE