Is it possible to define unitary operator-valued stochastic process and related stochastic differential equations?

88 Views Asked by At

There are many references on stochastic differential equations valued in Hilbert or Banach space which are driven by diffusion processes also on Hilbert space. Now, I am wondering if there are any reference or theory on how to define a stochastic processes valued in unitary operators between Hilbert spaces. Moreover, is it possible to define stochastic differential equations valued in unitary operators? Thank you so much!

1

There are 1 best solutions below

1
On BEST ANSWER

Yes, this is possible, and apparently this is a thing in quantum mechanics (I learned after some googling). The important thing here is to realize that you need a stochastic integration theory on a group, hence you need an integration theory with respect to the Haar measure of that group. Adding this to your google search should help you in finding the kind of research you want, for example https://link.springer.com/content/pdf/10.1023%2FA%3A1007816930696.pdf