1841年，Delaunay获得如下定理：如果在一平面上沿定直线滚动一条二次圆锥直线，然后将其焦点的轨迹绕定直线旋转，则所得到的曲面具有常数......

Along with the construction of non-Lorentz-invariant effective field theories, recent studies which are based on geometr......