1,315 reputation
1815
bio website math.mit.edu/~jblewis
location Massachusetts
age 29
visits member for 4 years, 5 months
seen Jun 18 '12 at 19:10
I am a graduate student at MIT. See my webpage for more information.

Mar
15
awarded  Yearling
Jun
25
awarded  Excavator
Mar
15
awarded  Yearling
Dec
8
awarded  Popular Question
Mar
15
awarded  Yearling
Apr
5
comment probability that a random element of Z/NZ can be written as a subset sum of others
It seems to me like the question in the postscript asks for the probability that every element of $\mathbb{Z}/ N \mathbb{Z}$ can be written as a sum of some elements of $A$, whereas the original question asks for the probability that a particular element in $\mathbb{Z}/ N \mathbb{Z}$ can be written as a sum of some elements of $A$; which question are you really interested in?
Apr
4
comment Finding cycle with constraints
It might be helpful if you described your algorithm for cycles of even length. Also, what is the motivation?
Apr
4
comment Finding cycle with constraints
Please edit for typos and LaTeX. Such a cycle obviously need not exist -- what is the actual question you intend? Is this a homework assignment?
Mar
24
comment volume of the projected body
What sort of answer are you looking for?
Mar
24
comment Fun question in additive combinatorics
Yes, my mistake.
Mar
24
comment Fun question in additive combinatorics
Is this a question to which you already know the answer?
Mar
24
comment Maximal number of directed edges in suitable simple graphs on $n$ vertices without directed triangles.
gordon-royle, this is ruled out for $k \geq 2$ by the condition that there be no 2-cycles.
Mar
22
comment Assigning positive edge weights to a graph so that the weight incident to each vertex is 1.
@Didier Piau, good question!
Mar
22
comment A density on the natural numbers invariant with respect to the multiplication
Which is consistent with what I wrote: Gerald Edgar's density is the limit of a subsequence of the sequence whose limit is the usual density.
Mar
22
revised Assigning positive edge weights to a graph so that the weight incident to each vertex is 1.
added 88 characters in body
Mar
22
revised Assigning positive edge weights to a graph so that the weight incident to each vertex is 1.
added 222 characters in body
Mar
22
comment Assigning positive edge weights to a graph so that the weight incident to each vertex is 1.
Yes, that's correct. I'll edit to make it clearer.
Mar
22
comment A density on the natural numbers invariant with respect to the multiplication
(In fact, your proposed definition must agree with the usual one whenever the usual one exists.)
Mar
22
comment A density on the natural numbers invariant with respect to the multiplication
Then all the positive integers have density 1, but the even integers still have density 1/2. Right?
Mar
22
comment Assigning positive edge weights to a graph so that the weight incident to each vertex is 1.
Whoops, fair enough. All those pesky adjectives like "positive" and "connected" .... My apologies.