A 1-torus is a circle, you mean an annulus. You do NOT want to make this mistake at a topologist dinner party, trust me.
Damn, so what's the name of the shape that's a flat donut with an inner and outer circular perimeters? i.e. a filled circle with another smaller radius circular area subtracted from it. Or 2D cross section of a torus seen perpendicularly to the plane that intersects the widest part of the torus. A squished donut, or chubby circle, if you like.
A 1-torus is a circle, you mean an annulus. You do NOT want to make this mistake at a topologist dinner party, trust me.
Damn, so what's the name of the shape that's a flat donut with an inner and outer circular perimeters? i.e. a filled circle with another smaller radius circular area subtracted from it. Or 2D cross section of a torus seen perpendicularly to the plane that intersects the widest part of the torus. A squished donut, or chubby circle, if you like.
Annulus
Hah he said annulus