3

Does there exist an Ito's formula for function of Brownian Motion which are once differentiable but not twice differentiable like Tanaka's formula?

Lost1
  • 7,895

2 Answers2

4

Check out Karatzas & Shreve for Ito formulas for difference of convex functions. This normally has local time terms at the non differentiable points but these local time terms disappear in the case given in the question.

Lost1
  • 7,895
0

ALso Samuel N. Cohen and Robert J. Elliot show the desired result on page 339 in Stochastic Calculus and Applications (2015).