STOCHASTIC DIFFERENTIAL EQUATIONS
Obiettivi e contenuti del corso
1. Introducing Stochastic Calculus and its rules.
2. Introducing Stochastic Differential Equations.
3. Showing their utility in modelling evolutions with noise in different contexts such as Finance,
Engineering, Chemistry, Physics.
Descrizione degli argomenti trattati
1. Elements of Probability. Probability spaces, random variables. Variance, covariance, probability
distribution, density. Independence. Random vectors. Convergence of random variables. Charac-
teristic functions. Gaussian laws. Measurability theorems.
2. Stochastic processes. Filtrations. Trajectories. Equivalent processes, modifications, indistinguish-
able processes. Finite-dimensional laws and Existence Kolmogorov’s theorem. Kolmogorov’s conti-
nuity theorem. Stopping times.
3. Brownian motion. Definition and basic properties. Finite-dimensional distributions. The White
4. Conditional probability. Conditional expectations. The augmented Brownian filtration.
5. Martingales. Definitions and basic properties of continuous time Martingales.
6. The stochastic integral. Elementary processes. The stochastic integral. Ito Isometry. The stochastic integral as a process. Stopping theorems. Local martingales.
7. Stochastic calculus. Stochastic differential of an Ito process. Ito's Lemma. Girsanov’s Theorem. The martingales of the Brownian filtration.
8. Stochastic Differential Equations. A class of SDE. Definition of solutions. Existence and Uniqueness
theorems for the solution. SDE and Markov processes. Connections between SDE and PDE.
Organizzazione del corso e modalità di verifica
The course final exam is made of a preliminary written test, followed by an oral test, whose access is
subject to a passing rate in the written test.