0x67cca0ba March 8, 2025 \[ \DeclareMathOperator{\O}{O} \DeclareMathOperator{\GL}{GL} \]The orthogonal group \(\O(n)\) acts continuously on \(\mathbb{R}^n\) via vector-matrix multiplication. Remarks The orbits are \(\{0\}\) and all spheres. The orbit space \(\mathbb{R}^n/\O(n)\) is homeomorphic to \(\mathbb{R}^{\ge 0}\). See also Link to heading action of \(\GL(n)\) on \(\mathbb{R}^n\) action of \(\O(n)\) on \(\mathbb{S}^{n-1}\)