MathDB
Abc conjecture

Source: Iran 2005

September 21, 2005
number theorygreatest common divisorlogarithmsgeometrynumber theory proposed

Problem Statement

For each mNm\in \mathbb N we define rad (m)=pirad\ (m)=\prod p_i, where m=piαim=\prod p_i^{\alpha_i}.
abc Conjecture Suppose ϵ>0\epsilon >0 is an arbitrary number, then there exist KK depinding on ϵ\epsilon that for each 3 numbers a,b,cZa,b,c\in\mathbb Z that gcd(a,b)=1gcd (a,b)=1 and a+b=ca+b=c then: max{a,b,c}K(rad (abc))1+ϵ max\{|a|,|b|,|c|\}\leq K(rad\ (abc))^{1+\epsilon}
Now prove each of the following statements by using the abcabc conjecture : a) Fermat's last theorem for n>Nn>N where NN is some natural number. b) We call n=piαin=\prod p_i^{\alpha_i} strong if and only αi2\alpha_i\geq 2. c) Prove that there are finitely many nn such that n, n+1, n+2n,\ n+1,\ n+2 are strong. d) Prove that there are finitely many rational numbers pq\frac pq such that: 23pq<21384q3 \Big| \sqrt[3]{2}-\frac pq \Big|<\frac{2^ {1384}}{q^3}