Refracted Lévy processes
Kyprianou, A. E. ; Loeffen, R. L.
Ann. Inst. H. Poincaré Probab. Statist., Tome 46 (2010) no. 1, p. 24-44 / Harvested from Project Euclid
Motivated by classical considerations from risk theory, we investigate boundary crossing problems for refracted Lévy processes. The latter is a Lévy process whose dynamics change by subtracting off a fixed linear drift (of suitable size) whenever the aggregate process is above a pre-specified level. More formally, whenever it exists, a refracted Lévy process is described by the unique strong solution to the stochastic differential equation ¶ dUt=−δ1{Ut>b} dt+dXt, ¶ where X={Xt : t≥0} is a Lévy process with law ℙ and b, δ∈ℝ such that the resulting process U may visit the half line (b, ∞) with positive probability. We consider in particular the case that X is spectrally negative and establish a suite of identities for the case of one and two sided exit problems. All identities can be written in terms of the q-scale function of the driving Lévy process and its perturbed version describing motion above the level b. We remark on a number of applications of the obtained identities to (controlled) insurance risk processes.
Publié le : 2010-02-15
Classification:  Stochastic control,  Fluctuation theory,  Lévy processes,  60J99,  60G40,  91B70
@article{1267454106,
     author = {Kyprianou, A. E. and Loeffen, R. L.},
     title = {Refracted L\'evy processes},
     journal = {Ann. Inst. H. Poincar\'e Probab. Statist.},
     volume = {46},
     number = {1},
     year = {2010},
     pages = { 24-44},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1267454106}
}
Kyprianou, A. E.; Loeffen, R. L. Refracted Lévy processes. Ann. Inst. H. Poincaré Probab. Statist., Tome 46 (2010) no. 1, pp.  24-44. http://gdmltest.u-ga.fr/item/1267454106/