Thank you for the article. I'm wondering whether the geometry of a "sphere" in flat space 4D would include any corners? How about in the exotic R4s? If so, how many corners would there be?

## points on a 4D sphere

Thank you for the article. I'm wondering whether the geometry of a "sphere" in flat space 4D would include any corners? How about in the exotic R4s? If so, how many corners would there be?