On the sharpness of Siegel's Lemma

Jul 23, 2016

Speakers

About

Siegel's Lemma is a key tool in transcendental number theory and diophantine approximation. It is a clever application of the Pigeonhole Principle—a ``pure existence argument''—with strikingly powerful consequences. Suppose we have a homogeneous system of linear equations with integer coefficients: n equations, N variables with N>n, and every coefficient has absolute value ≤A. PROBLEM: Give an upper bound to the maximum norm of the smallest nontrivial integer solution. Sharpest known form of Siegel's Lemma gives the upper bound (70N−−√A)n/(N−n). It is easy to show that the factor A cannot be replaced by o(A) (hint: use primes). So, A=1 is the most interesting special case. Hard Question: Assuming A=1 , can we replace the base N−−√ in the upper bound (N−−√)n/(N−n) with a smaller base o(N−−√) ? The answer is no: We prove that the sharpest known form of Siegel's Lemma is best possible. We outline the long proof.

Organizer

Categories

About The Mathematics of Jiří Matoušek

International Conference on The Mathematics of Jiří Matoušek, Charles University, Prague 2016

Store presentation

Should this presentation be stored for 1000 years?

How do we store presentations

Total of 0 viewers voted for saving the presentation to eternal vault which is 0.0%

Sharing

Recommended Videos

Presentations on similar topic, category or speaker

Interested in talks like this? Follow The Mathematics of Jiří Matoušek