50,362 reputation
467138
bio website linkedin.com/pub/…
location Illinois
age 40
visits member for 3 years, 8 months
seen 6 hours ago

I'm a mix of things, a physicist by education, I earn my living as a mathematician and programmer working at Wolfram Research. I thoroughly enjoy learning and discovery process.


“Technical skill is mastery of complexity, while creativity is mastery of simplicity”
— Erik Christopher Zeeman

Project Euler


Dec
30
comment Probability that rolling X dice with Y sides and summing the highest Z values is above some value k
Suppose an exploding dice roll first resulted in 10, and then in 3, am I correct in concluding that its score equals 13?
Dec
20
comment Finding $ \int_0^1 \frac {\ln x}{1+x^2}\mathrm dx $
What is "the $n$th Catalan constant"?
Dec
20
comment Derivation of the third moment of Poisson distribution using Stein-Chen identity
@Dominik To help keep down the number of unanswered questions, could you please paste your correct solution down as an answer, and accept it. Thank you!
Dec
20
awarded  Constituent
Dec
19
comment Are the poll results likely to be valid if they are based on only those subjects who agree to respond?
This question might be better suited for stats.stackexchange.com
Dec
17
comment Expectation of the maximum of gaussian random variables
An example, illustrating second point can be found here.
Dec
15
comment Calculating the Fourier transform of $\frac{\sinh(kx)}{\sinh(x)}$
@JohnZHANG It is obtained by writing sine as a linear combination of exponents, summing two geometric series and simplifying the result.
Dec
14
comment An intuitive understanding of the equation $Var(X)=E(X^2)-E(X)^2$
Is this a yes-or-no question? If so, the answer is in affirmative.
Dec
14
revised An intuitive understanding of the equation $Var(X)=E(X^2)-E(X)^2$
edited body
Dec
14
answered Prove that $a_n = 2^n$
Dec
13
answered Probability and stuff
Dec
12
revised Probability that $\max(X,Y)> a \min(X,Y)$ where $X$ and $Y$ are independent and uniformly distributed on $[0,1]$
added 129 characters in body
Dec
12
answered Probability that $\max(X,Y)> a \min(X,Y)$ where $X$ and $Y$ are independent and uniformly distributed on $[0,1]$
Dec
12
revised Probability that $\max(X,Y)> a \min(X,Y)$ where $X$ and $Y$ are independent and uniformly distributed on $[0,1]$
added 22 characters in body; edited title
Dec
10
answered sum and difference between two independent Poisson random variables
Dec
10
revised sum and difference between two independent Poisson random variables
added 26 characters in body
Dec
9
awarded  Caucus
Nov
29
answered Determine the Density Function of $(X_1/X_2)$
Nov
25
comment When does $\int_0^t dX_s = X_t-X_0$ hold for a stochastic process?
What is the definition of stochastic integral you are working with?
Nov
15
comment Prove that $\frac{d^n}{dx^n} (\sin^4 x + \cos^4 x) = 4^{n-1}\cos (4x + \frac{n\pi}{2})$
Use $$ \sin^4(x) + \cos^4(x) = \frac{3}{4} + \frac{1}{4} \cos(4 x)$$ and an easy $\frac{d^n}{d x^n} \cos(a x) = a^n \cos\left(a x + \frac{\pi n}{2} \right)$.