Alphabeta Math

Itos Formula and Brownian Martingales

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1 · Prerequisites
Abstract Algebra
Combinatorics
Coxeter Groups
Functional Analysis
Linear Algebra
Measure Theory
Number Theory
Probability
Real Analysis
Set Theory
Topology
2 · Logical flowchart

3 · Items

Definition

Continuous Brownian Ito processes

Definition

Quadratic covariation of Brownian Ito processes

Theorem

Quadratic covariation of Brownian Ito processes

Theorem

Integration by parts for Brownian Ito processes

Theorem

One-dimensional Ito formula

Theorem

Multidimensional Ito formula for Brownian-driven processes

Corollary

The Brownian square martingale

Corollary

The exponential Brownian martingale

Theorem

Space-time harmonic functions yield Brownian local martingales up to exit lifetime

Corollary

Heat-semigroup martingales

Lemma

Characteristic exponential for a continuous local martingale with deterministic clock

Theorem

Levy characterization of Brownian motion

Corollary

Vector Levy characterization

Definition

The Brownian differential generator

Theorem

Dynkin formula for bounded Brownian stopping

Remark

Ito versus Stratonovich boundary

Remark

General semimartingale calculus is outside this block

Lemma

A closed L2 subspace with trivial orthogonal complement fills L2

Theorem

Brownian-filtration martingale representation

Corollary

Square-integrable Brownian terminal variables have Ito representations

Corollary

Cadlag Brownian-filtration local martingales have continuous versions

Sources