The surface parameterized by \(X:(u,v)\mapsto (\cos u,\sin u,2\cos v,2\sin v)\) is a torus in \(\mathbb {R}^4\) with the induced metric \(ds^2=X^*ds^2_{\mathbb {R}^4}\). Show that this torus cannot be isometrically immersed into \(\mathbb {R}^3\).
Question
Math 6510 • Differentiable Manifolds
Fall 1994 • Question 18