Il giorno martedi' 20 maggio 2014, alle ore 12:00, il professor
Jean Jacod
Universite' Pierre et Marie Curie, Paris
terra' un seminario dal titolo
Is a discretely observed semimartingale of Ito type?
presso il Dipartimento di Matematica del Politecnico di Milano
(aula seminari "Fausto Saleri", sesto piano).
Tutti gli interessati sono cordialmente invitati.
Marco Fuhrman
Abstract.
In high-frequency statistics, and among various hypotheses, the fact
that the underlying
observed process is an Ito semimartingale is always assumed. However,
for financial data for example,
prices should be semimartingales (because of the "fundamental asset
pricing theorem"),
but there is no reason why it should be an Ito semimartingale.
So it is important to derive tests for checking whether this
assumption is enforced, or not.
The problem cannot be solved in full generality, but we will see that
under some restrictive
structural assumptions, plus the fact that the process is continuous,
some tests can be constructed.
This is joint work with Yacine Ait-Sahalia.