New posts in differential-geometry

understanding of the first fundamental form

If $\omega$ is a 2-form on $\mathbb{R}^4$ and $\omega \wedge \omega = 0$, then $\omega$ is decomposable.

Defining curvature via osculating circles

how to calculate the curvature of an ellipse

Divergence of Gradient of the Unit Normal, and Curvature Equation

Intuition for Cohomology and Holes in a Space

Reference request: Vector bundles and line bundles etc.

The differential of the inclusion map is the inclusion map of tangent spaces.

A difficult question about diffeomorphism about submanifold

What does it mean for Euclidean geometry of the sphere to be inherited from 3-d Space

"Maximal symmetry" metric for a manifold?

Local diffeomorphism from $\mathbb R^2$ onto $S^2$

Parametrization of $n$-spheres

Relations between curvature and area of simple closed plane curves.

How do we obtain a chart for the sphere $\{x:\|x\|=1\}$ from a chart of the ball $\{x:\|x|\le1\}$?

Hodge Theory, intuition?

How to convince a high school student that differentials don't work like fractions in general?

Local existence of parallel vector field

How much algebraic geometry is there in complex geometry (for example, Demailly)?

How can I show that if the second fundamental form of a surface is identically equal to zero, then the surface is a plane?