6,916 reputation
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bio website math.haifa.ac.il/~seva
location Israel
age 53
visits member for 4 years, 10 months
seen 5 hours ago
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Aug
27
comment Uniformly small sums of roots of unity
@Greg: I have reworked the answer, so comments made earlier seem irrelevant now. You can just delete them if you agree.
Aug
27
revised Uniformly small sums of roots of unity
added 568 characters in body
Aug
26
comment What is the maximum size of a set system where the intersection of any two incomparable members is not in the set?
The concluding part of your argument is a little vague and in fact, it seems that you can add an arbitrarily chosen set of size larger than $t+1$ to the family of all $(t+1)$-sets while keeping the property in question. (Think, for instance, of the set $[n]$ itself.)
Aug
20
accepted Smoothening a measure, II
Aug
20
revised Smoothening a measure, II
added 99 characters in body
Aug
19
asked Smoothening a measure, II
Aug
19
accepted Smoothening a probability measure
Aug
19
revised Smoothening a probability measure
rolled back to a previous revision
Aug
19
revised Smoothening a probability measure
added 276 characters in body
Aug
19
asked Smoothening a probability measure
Aug
13
comment Maximal Number of Pairs of Orthogonal vectors in a set of $n$ vectors in $\mathbb{R}^3$
I wonder whether this correspondence works for the finite vector space ${\mathbb F}_q^r$. Assuming we have a system of $n$ points and $l$ lines in ${\mathbb F}_q^r$ that determines $I$ incidences, how many points we get in ${\rm PG}(r,q)$ and how many pairs of them will be orthogonal?
Jul
6
answered Uniformly small sums of roots of unity
Jul
3
comment Differences of consecutive ordered fractional parts
@Clark Kimberling: I expanded my answer a little to address the general case of $h\ne 0$. Does this answer your question?
Jul
1
revised Differences of consecutive ordered fractional parts
added 545 characters in body
Jul
1
comment When are the powers of 2 sum-free mod n?
What are the values of $n$ smaller than, say, $100$, with the property in question? What does OEIS say?
Jun
30
revised Differences of consecutive ordered fractional parts
Typo fixed
Jun
30
answered Differences of consecutive ordered fractional parts
Jun
1
awarded  Revival
May
31
revised When is $1+a+a^2+\dotsb+a^{{\rm ord}_n(a)-1}$ divisible by $n$?
deleted 45 characters in body; edited title
May
30
answered When is $1+a+a^2+\dotsb+a^{{\rm ord}_n(a)-1}$ divisible by $n$?