All Questions
5 questions
2
votes
0
answers
62
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Maximum distance between consecutive terms in sequence with arbitrarily long APs
Good evening. I am writing a paper on complex analysis, and as a corollary (of my work and others'), I believe that I have managed to deduce the following result.
Proposition: Let $n_1 < n_2 \cdots ...
0
votes
0
answers
125
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An exercise about sum-product estimate
I am struggling with 1.11 exercise from the George Shakan "Discrete Fourier Transform".
Let $A \subset \mathbb{Z}/q\mathbb{Z}$ be any set not containing zero with $|A|>\sqrt2q^{5/8}$. ...
5
votes
0
answers
215
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Showing that Fourier pseudorandomness is insufficient for $k=4$ case (four arithmetic progressions)
I wish to show that the Fourier pseudorandomness is insufficient to count the number of 4-term arithmetic progression.
Let $A \subset \mathbb{Z}/N\mathbb{Z}$ be a subset of a cyclic group $\mathbb{Z}/...
24
votes
4
answers
3k
views
What is the shortest route to Roth's theorem?
Roth first proved that any subset of the integers with positive density contains a three term arithmetic progression in 1953. Since then, many other proofs have emerged (I can think of eight off the ...
3
votes
1
answer
183
views
Some sums related to a quadratic polynomial over $\mathbb{F}_2^n$
For any $c \in \mathbb{F}_2^n$ define $\sigma_c: \mathbb{F}_2^n \to \mathbb{F}_2$ the quadratic polynomial defined for $v = (v_1,v_2,...,v_n)$ by:
$$ \sigma_c (v) = \sum_{i=1}^n v_iv_{i+1} + c_iv_i $...