3,593 reputation
619
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location Washington, DC
age 61
visits member for 3 years, 4 months
seen 17 hours ago

I am a math professor at Georgetown University, with broad mathematical interests.

Check out the textbook "Mathematics and Climate" by Hans Kaper and me, published in October 2013 by SIAM.


17h
reviewed Approve suggested edit on Normal Distribution Worded Problem
17h
reviewed Approve suggested edit on What is the average of no numbers?
17h
reviewed Close Triangle Inequality on complex numbers
17h
reviewed Close There are mn+1 different integers randomly arranged
17h
reviewed Leave Open Prove that function is inner product
Aug
12
comment Heat semigroup on Morrey spaces
The simplest case to consider would be $n = p = q = 1$.
Aug
6
reviewed Close Showing the series converges
Aug
6
reviewed Approve suggested edit on What's wrong with this proof of the infinity of primes?
Aug
6
reviewed Reject suggested edit on Differential problem, how to get y''?
Aug
6
reviewed Approve suggested edit on Use a triple integral to find the volume of a tetrahedron
Jul
27
comment Reverse Cauchy Schwarz for integrals
Use $f^2(x) = f(x) \cdot g(x) \cdot \frac{f(x)}{g(x)} \le f(x) \cdot g(x) \cdot \frac{M_1}{m_2}$ and a similar inequality for $g^2(x)$.
Jul
25
comment Prove two solutions of differential equation are the same
Note that we can assume $C_2 = 0$ or $C_3 = 0$, since both are additive constants.
Jul
25
comment Prove two solutions of differential equation are the same
Have you tried to plot the two functions for different choices of $C1, \dots C_4$ - just to check that these are really the same?
Jul
20
comment How to transform a maximizing objective function which contains a max operator to a standard LP form
This is the right start, however, $z$ should not be restricted to be a binary variable. In particular, this is no longer a linear program (it's an integer program) and it is possible that with this approach the problem no ponger has feasible solutions.
Jul
17
answered Let $A = \{1/2 < |z| < 2\}.$ Is there an analytic function $f$ on $\mathbb{C} \setminus \{0\}$ so that $Im(f) < −1$ on $∂A$ and $f(1) = 0$?
Jul
16
comment Distribution of reversed k-th order statistics
First off, your distribution function assumes that $X_i \sim U(0,1)$ (which is not a big restriction). As to your question, if, say, $n = 5$ and $Y_{(2)} = .3$, what do you think is $Y_4$ (using descending order)? Do you see what is going on?
Jul
16
reviewed Close Proof of Gram-Schmidt
Jul
16
reviewed Close Sum of series with triangular numbers
Jul
16
reviewed No Action Needed recurrence relation dependent inversly on n
Jul
16
reviewed Leave Open Dimension of R over Q without cardinality argument.