Tag Archives: Hadamard matrix

A public lecture

Posted on 08/12/2015 by Peter Cameron

This evening, Jonathan Jedwab gave a public lecture, in celebration of the fact that it is Jacques Hadamard‘s 150th birthday. The title of the lecture was “What is a research mathematician?”, and the hook linking the two was Hadamard matrices. … Continue reading →

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A matrix problem

Posted on 19/08/2011 by Peter Cameron

Suppose you are given n linearly independent vectors in n-dimensional Euclidean space. You move the vectors so that each vector becomes longer, but their inner products remain the same. What happens to the volume of the parallelepiped they span? This … Continue reading →

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Team games, 1

Posted on 14/03/2011 by Peter Cameron

Laurent asked on my blog: Given n players, arrange a competition in which, in each match, two teams of k players play each other. We require that any two players are on the same team in a fixed number s … Continue reading →

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