SUMMARY:
- title slide (slide 1)
- correction: "obligation derivative" more commonly called
an "off-market forward" (slides 2-3)
- notations for functions and expressions -- evaluation (slide 4)
- notations for functions and expressions -- differentation (slides 5-8)
- examples of differentiation of functions and expressions (slides 9-10)
- deriv. of expression agrees with deriv. of function (slide 11)
- continue a gauche, limite a droite for expressions and
funcions (slide 12)
- the product rule, or differentiation by parts (slides 13-16)
- the quotient rule (slides 17-18)
- the chain rule (slides 19-21)
- a practice differentiation problem (slide 22)
- logarithmic differentiation (slides 23-25)
- basics of integration (slide 26)
- review of the Fundamental Theorem of Calculus,
in various forms (slides 27-36)
- review of Integration by Substitution in one variable
(slides 37-45)
- review of general Integration by Substitution in multi-variables
(slide 47)
- the special case of polar coordinates (slides 48-58)
- review of Integration by Parts (slides 59-60)
- remainder of lecture:
limits of powers of functions after renormalization,
and other limits;
financial mathematics integrals;
pricing problem - reduction to an integral;
pricing problem - calculation of the integral;
the Central Limit Theorem - statement
(slide 61)
- second act of Lecture 4 title slide (slide 62)
- some simple limits of quotients of polynomials (slide 63)
- compounding with n conversions; continuous compounding
givs a limit that needs to be calculated (slide 64)
- one approach to computing that limit (slides 65-67)
- the limit of renormalized powers of 1-x^2, the algebra (slide 68)
- the limit of powers of 1-x^2, the graphs (slides 69-72)
- renormalization, one of the graphs (slide 73)
- the limit, the graph (slide 74)
- more limits of renormalized powers (slide 75)
- Maclaurin approximations (slide 76)
- examples of Maclaurin approximations (slide 77)
- renormalized powers of cosine, the graphs (slides 78-81)
- the limit, the graph (slide 82)
- the general fact: the limit of renormalized powers when
the second order Maclaurin approximation is 1-x^2/2 (slide 83)
- proof for x=3 (slides 84-89)
- the hypothesis that f'' is continuous at 0 (slide 90)
- statement of the fact, as a theorem (slide 91)
- similar results, for other second-order Maclaurin approximations
(slide 92)
- the general theorem: the second-order Maclaurin approximation
determines the limit of the renormalized nth power (slide 93)
- thin tails for the bell curve, the picture (slide 94)
- fat tails for another function, the picture (slide 95)
- the bell curve hugs the x-axis to the left and right,
the picture (slide 96)
- the bell curve hugs the x-axis to the left and right,
symbolic verification through limits (slide 97)
- exponentials of quadratics with negative quadratic coefficient
always tend to 0 at plus or minus infinity (slide 98)
- extending this result to the complex plane,
the limits along horizontal lines are zero (slides 99-103)
- the integral along a vertical segment tends to zero as the
segment moves infinitely to the right or left (slide 104)
- remainder of lecture:
financial mathematics integrals;
pricing problem - reduction to an integral;
pricing problem - calculation of the integral;
the Central Limit Theorem - statement
(slide 105)
- third act of Lecture 4 title slide (slide 106)
- the integral of e^{-x^2/2} from minus infinity to infinity
(slides 107-110)
- integration of an exponential of a quadratics
from minus infinity to infinity; use of Cauchy's Theorem
(slides 111-119)
- the CDF of the standard normal distribution, called \Phi
(NOTE: Contrary to what the slide says, this is *not*
typically called the "error function", though the
error function is related to this) (slide 120)
- definite integrals of an exponential of a quadratics;
completing the square in the exponent (slide 121)
- exercise: a related integral (slide 122)
- integration (from minus infinity to infinity)
against e^{-x^2/2} of the positive part of:
the difference between an exponentiated linear and a constant;
preparation for development of the Black-Scholes
Option Pricing Formula (slides 123-127)
- integration against e^{-x^2/2} of polynomials;
a recrusion formula (slides 128-136)
- remainder of lecture:
pricing problem - reduction to an integral;
pricing problem - calculation of the integral;
the Central Limit Theorem - statement
(slide 137)
- fourth act of Lecture 4 title slide (slide 138)
- a call option priced via a discrete model with
over 2.5 million subperiods, setup and payoff function (slide 139)
- the risk-neutral world for this option (slide 140)
- the model of the underlying, the ending underlying price
and the contingent claim (slide 141)
- the price as an expected value (slide 142)
- the corresponding coin-flipping game (slide 143)
- an easier coin-flipping problem; some notation (slide 144)
- restatement of the easier problem; more notation;
a strategy for tackling the easier problem via a
sequence of even easier problems, but of increasing difficulty
(slide 145)
- the distribution of the first difference;
intuitive definition of a random variable;
another random variable with the same distribution (slide 146)
- the generating function and Fourier transform of the distribution
of the first difference; the inverse Fourier transform; what
happens on dividing the first difference by 7, start (NOTE:
Contrary to what is said in the slide, this generating function is
not typically called the "moment generating function", but the
moment generating function is closely related) (slide 147)
- what happens on dividing the first difference by 7, end (slide 148)
- the distribution of the second difference (slide 149)
- the generating function and Fourier transform of the
distribution of the second difference (slide 150)
- the generating function and Fourier transform of the distribution
of the Nth difference (slide 151)
- what happens on dividing the Nth difference by the
square root of N; the renormalized Nth power of cosine (slide 152)
- estimation via the limit of this renormalized Nth power (slides 153-156)
- the key idea of the Central Limit Theorem: after this estimation,
take the inverse Fourier transform (slide 157)
- the distribution of the variable Z (slide 158)
- some probabilities for Z (slides 159-160)
- the generating function and Fourier transform of the
distribution of Z (slides 161-162)
- Z approximates X,
which is the Nth difference over the square root of N (slide 163)
- our restated easier problem, and an approximate solution (slide 164)
- a new easier problem, involving expected values (slide 165)
- another easier problem, involving expeceted values (slide 166)
- another easier problem, involving expected values of a
function of Z (slide 167)
- another easier problem, involving expected values of a function of
X, and its approximate solution using the fact that Z is close to
X (slides 168-169)
- another easier problem, involving any "reasonable" function g
of X, with the hope that a good choice of function will solve
achieve our goal (slide 170)
- finding the right choice for g (slides 171-175)
- reduction of our goal to an integral (slide 176)
- remainder of lecture:
pricing problem - calculation of the integral;
the Central Limit Theorem - statement
(slide 177)
- fifth act of Lecture 4 title slide (slide 178)
- resttatement of the integral we need to calculate (slide 179)
- getting rid of the positive part (slide 180-181)
- splitting the problem into two integrals (slide 182)
- computation of the two integrals (slides 183-186)
- plugging in the numbers (slide 187)
- approximate solution of the original coin-flipping game and
option pricing problem (slide 188)
- a more realistic restatement of the bank assumption
(slide 189)
- a more realistic restatement of the stock assumptions
(slides 190-193)
- the 50-50 drift and volatility equations (slide 194)
- a discrete model with only 10 subperiods, and with
the same stock assumptions (slides 195-197)
- more and more subperiods, limiting on the Black-Scholes model
(slide 198)
- the Black-Scholes Option Pricing Formula (slide 199)
- moving from 50-50 probabilities to 65-35 gives the same answer,
in the limit (slides 200-204)
- remainder of lecture:
the Central Limit Theorem - statement
(slide 205)
- sixth act of Lecture 4 title slide (slide 206)
- reminder of our approximate solution, as an integral (slide 207)
- the 50-50 Central Limit Theorem, motivation and
intuitive statement (slide 208)
- toward a more concise intuitive statement (slides 209-212)
- exponentially bounded (exp-bdd) functions (slides 213-214)
- a more rigorous statement of the Central Limit Theorem (slide 215)
- exact formulas for the expected values appearing in
the theorem, for small values of N (slides 216-217)
- first fully rigorous satement of the Central Limit Theorem,
based on expected value formulas; future goal of
formulating a good mathematical model for coin-flipping,
via "independent" random variables (slide 218)
- a plan for seven future lectures:
- Random variables
- The Central Limit Theorem Redux
- Girsanov's Theorem
- First Derivation of Black-Scholes
- Stochastic Processes
- Ito's Lemma
- Black-Scholes Redux
MATH RULES!! (slide 219)