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16h
revised How far do I need to drive to find an empty parking spot?
Fixed typos and misspeaks (open for closed, etc.) Should be less confusing
May
18
comment Can a Matrix with positive entries have a negative eigenvalue?
Can a matrix with positive entries have a negative determinant?
May
18
answered Applied Mathematics Question - 30 Lightbulbs; Desynchronization and resynchronization
Apr
17
comment What is the determinant of the sum of a diagonal matrix and a matrix of ones?
See math.stackexchange.com/questions/219731/… (The chosen answer handles your case, even though the question doesn't)
Mar
31
awarded  Nice Question
Mar
5
comment Expected Value of an inefficient estimator of the $\beta$ parameter of a simple linear regression
$E[\tilde\beta]=\beta$ means the estimator is unbiased, not the same thing as consistency.
Feb
27
comment Proof of Frobenous Coin Problem lower bounds (Chicken McNugget theorem)
See math.stackexchange.com/questions/865024/…
Feb
20
awarded  Good Answer
Feb
17
answered What is the size of $\{(x_1,\ldots,x_n)\in\mathbb{R}^n:x_1+\cdots+x_n<a\text{, and }x_i>0\}$?
Feb
15
comment Measure of the set of periodic points of a measure preserving map
In the specific case I was looking at the maps are invertible. If that restriction makes the problem tractable, by all means use it.
Feb
7
comment Measure of the set of periodic points of a measure preserving map
That is what I meant by a rubber sheet, you are just pulling the outer ring, and the annulus stretches.
Feb
7
comment Measure of the set of periodic points of a measure preserving map
The region is convex, therefore connected, and the map is definitely continuous (piecewise linear for now, but the general continuous case is of interest).
Feb
7
comment Measure of the set of periodic points of a measure preserving map
Yes, I was assuming that $D$ was connected (in fact the case that I am interested in has $D$ convex. I have edited the question (which now feels like cheating).
Feb
7
revised Measure of the set of periodic points of a measure preserving map
Added restriction to convexity
Feb
5
revised Measure of the set of periodic points of a measure preserving map
Added close but no cigar example
Feb
4
asked Measure of the set of periodic points of a measure preserving map
Sep
30
awarded  Explainer
Sep
20
comment A Step in the proof of Rate of Convergence of Steepest Descent in Nocedal's Numerical Optimization
You are missing a $\bigtriangledown$ in your expansion. Next compute the derivative. Then remember the definition of $\bigtriangledown f$ in the first paragraph.
Sep
16
comment The number of lattice points in d-dimensional ball
I think you need $d\ge 4$. The statement is definitely false for $d=1$ and $d=2$.
Sep
11
reviewed Approve Verify that the sets B and S are spanning sets for $\mathbb{R}^3$.