
5. Let (S2,F,P) be a probability space and let {W(t),t 2 0) be Brownian mo- tion with respect to ...
Problem 1.11. Let P be a probability measure on R, equipped with the Borel ơ-algebra. Let F(x)-P((-00,2]). P rove that f is non-decreasing right-continuous, F(x) → 0 as x →-00, and F(x) → 1 as x → oo. Prove that if P and Q are two probability measures such that P((-oo, x Q((-00,x]) for all x rational, then P , ie. P(A) = Q(A) for any Borel- measurable set A.
Let W - {Wi,0< t < ) represent a standard Brownian motion Show that the process Z(s)-(zt-W f.0 < t-1) is a standard Brownian motion, where s > 0 is fixed
(6 marks) Consider a filtered probability space (2,F,P, Ftte.). a. (2 marks) Let the stochastic process (Xo.7] have independent increments and sat- b. (2 marks) Let eo.] be a stochastic process with Ep[X] Xo for all t E [0,T]. Is c. (2 marks) Let (W be a Brownian motion. Given c 0, and define the stochastic isfies Ep[IXll < oo fort [0,T]. Is the stochastic process {Ztieo.r], where z, = xt-EP[Xt] is a martingale with respect to {Ft}120 ? Explain....
let {X(t), 1 2 0} denote a Brownian motion 8.1. Let Y(t) = tx(1/t). (a) What is the distribution of Y(t)? (b) Compute Cov(Y(s), Y()) (c) Argue that {Y(t), t 2 0] is also Brownian motion (d) Let Using (c) present an argument that
let {X(t), 1 2 0} denote a Brownian motion
8.1. Let Y(t) = tx(1/t). (a) What is the distribution of Y(t)? (b) Compute Cov(Y(s), Y()) (c) Argue that {Y(t), t 2 0] is also Brownian motion...
Let X(t), t ≥ 0 be a Brownian motion process with drift parameter µ = 3 and variance parameter σ2 = 9. If X(0) = 10, find P(X(2) > 20).
3. Let U-Bt- tB be Brownian bridge on [0, 1], where {BiJosesi is a Brownian process (i) Show E(Ut0 (ii) Show Cov(U,, Ut) s(1- t) for 0 s ts1. (ii) Let Xg(t)B Find functions g and h such that X, has the same covariance as a Brownian bridge.
3. Let U-Bt- tB be Brownian bridge on [0, 1], where {BiJosesi is a Brownian process (i) Show E(Ut0 (ii) Show Cov(U,, Ut) s(1- t) for 0 s ts1. (ii) Let Xg(t)B...
(2) Let X be a locally compact Hausdorff space, and let μ be a regular Borel measure on X such that μ(X) = +oo. Show that there is a non-negative function f CO(X) such that Jfdlı-+oo. Idea. Construct a sequence {K f-Σ001 nzfn, n} of disjoint compact sets K n with μ(An) > n and set where fn E Co(X) with XKn S f 31 く!
(2) Let X be a locally compact Hausdorff space, and let μ be a...
5. (20%) Let X be a continuous random variable whose probability density function is fr(x) (a +bx)%0(x) (a) If Ex)f find a and b. (b) Give the cumulative distribution function F,(x) f()dt of X and Var(X) (c) Let A be any Borel set of R. Define P by P(A) [,f dm
5. (20%) Let X be a continuous random variable whose probability density function is fr(x) (a +bx)%0(x) (a) If Ex)f find a and b. (b) Give the cumulative distribution...
complete measure space (i.e. ВЕА, "(В) — 0, АсВ — АЄ (5) Let (Q, A, м) be a A, u(A) = 0). Let f,g : Q+ R* be a pair functions. Assume that f is measurable g almost everywhere and that f (a) Prove that g is measurable (b) Let A E A and assume that f is integrable on A. Prove that g is integrable on A and g du
complete measure space (i.e. ВЕА, "(В) — 0, АсВ...
3. Brounian motion f(O)eR+ is a special case of a Gaussian process with mean zero and covariance C(s, t) = min(s, t) (a) What is the distribution of f(1), the Brownian motion at time t = 4? (Hint: it may be useful to function recall that for any random variable X, var(X)-(x, X) (b) Fix tE R. What is the distribution of f(t)? (c) What is the distribution of f(4)-f(2)? (Hint: it may be useful to utilize var(X-Y) = var(X)...