2022年2月24日
Matrix Analysis
摘要： Norm Norm for vectors \[ \begin{aligned} &\|x\| \geq 0 \\ &\|x\|=0 \text { if and only if } x=0 \\ &\|c x\|=|c|\|x\| \\ &\|x+y\| \leq\|x\|+\|y\| \end{ 阅读全文
posted @ 2022-02-24 21:48 narip 阅读(42) 评论(0) 推荐(0)
Spacelike, timelike and lightlike
摘要： Quoted from StackExchange. Suppose we have two events \((x_1,y_1,z_1,t_1)\) and \((x_2,y_2,z_2,t_2)\). Then we can define \(\Delta s^2 = -(c\Delta t)^ 阅读全文
posted @ 2022-02-24 19:36 narip 阅读(86) 评论(0) 推荐(0)