Here is a blog post that I think clarifies why this conjecture had remained unsolved: https://almostsure.wordpress.com/2009/09/27/the-gaussian-correlation-conje

Here is a blog post that I think clarifies why this conjecture had remained unsolved: https://almostsure.wordpress.com/2009/09/27/the-gaussian-correlation-conjecture/ https://almostsure.wordpress.com/2009/09/27/the-gaussian-cor... There is also a 'companion' article on arxiv that provides a clear presentation of Royen's proof: https://arxiv.org/abs/1512.08776 https://arxiv.org/abs/1512.08776