- #1

patric44

- 303

- 39

- Homework Statement
- what is the correct formula of the gradient in four vector notation

- Relevant Equations
- x_{mu}=(ct,-r)

hi guys

I am trying to learn special relativity and relativistic quantum mechanics on my own and just very confused about the different conventions used for the notation!?, e.g: the four position 4-vector some times denoted as

$$

x_{\mu}=(ct,-\vec{r})\;\;or\;as\;x_{\mu}=(ict,\vec{r})

$$

or for the contra-variant case

$$

x^{\mu}=(ct,\vec{r})\;or\;as\;x^{\mu}=(ict,\vec{r})

$$

the 4-gradiant also this way with 1/ic or 1/c, and sometimes the "time" component as x4 or as x0 , sometime with an "i" or without it, i tried to learn from different sources and most of them are different, what is the standard notation used for the position 4-vector and the gradient 4-vector? what is the easiest book to learn the subject for a beginner?

thanks in advance

I am trying to learn special relativity and relativistic quantum mechanics on my own and just very confused about the different conventions used for the notation!?, e.g: the four position 4-vector some times denoted as

$$

x_{\mu}=(ct,-\vec{r})\;\;or\;as\;x_{\mu}=(ict,\vec{r})

$$

or for the contra-variant case

$$

x^{\mu}=(ct,\vec{r})\;or\;as\;x^{\mu}=(ict,\vec{r})

$$

the 4-gradiant also this way with 1/ic or 1/c, and sometimes the "time" component as x4 or as x0 , sometime with an "i" or without it, i tried to learn from different sources and most of them are different, what is the standard notation used for the position 4-vector and the gradient 4-vector? what is the easiest book to learn the subject for a beginner?

thanks in advance