Hello, I want to ask you following question: I heard, that there is proof, that for every $n$, the area of a largest cross-section of a $n$-dimensional unit cube is $\sqrt{2}$. Google give me this link: What is known about unit cubes, but it only gives the estimate that it's no greater than $5$. So, is this problem solved?
There is related question: Area of cross-section (at midpoint perpendicular to longest diagonal) in the unit cube of dimension N

