Hopf formulas for nonlinear obstacle problems
Minimax theory and its applications, Tome 5 (2020) no. 2
A Hopf formula is derived for max{ut+H(Du), h(t, x)−u} = 0, u(T, x) = g(x) ≥ h(t, x), where g is assumed convex and x 7→ h(t, x) is also convex. This generalizes a formula without time dependent obstacle due to Subbotin. A Hopf formula for a concave obstacle is also derived. In addition, the Hopf formula for the obstacle problem with quasiconvex g is established. Next we consider the double obstacle problem. Assume the two obstacles g1(x) ≤ g2(x) are given functions, both convex or both concave. The nonlinear double obstacle variational inequality max{min{ut +H(Du), g2 −u}, g1 −u} = 0 on (−∞, T)×R n, with terminal data either g2 in the convex case and g1 in the concave case has a viscosity solution given by a Hopf type formula.These formulas are derived by using differential games with stopping times.
@article{MTA_2020_5_2_a0,
author = {Emmanuel N. Barron and Robert Jensen},
title = {Hopf formulas for nonlinear obstacle problems},
journal = {Minimax theory and its applications},
year = {2020},
volume = {5},
number = {2},
zbl = {1451.49039},
url = {http://geodesic.mathdoc.fr/item/MTA_2020_5_2_a0/}
}
Emmanuel N. Barron; Robert Jensen. Hopf formulas for nonlinear obstacle problems. Minimax theory and its applications, Tome 5 (2020) no. 2. http://geodesic.mathdoc.fr/item/MTA_2020_5_2_a0/