Four Vectors & Its application
Four Vector : $$x^{\mu}=\{ct,\overrightarrow{\mathbf{r}}\}$$$$x_{\mu} = \{ct,-\overrightarrow{\mathbf{r}}\}$$
Four Momentum : $$p^{\mu}=\{\frac{E}{c},\overrightarrow{\mathbf{p}}\}$$$$p_{\mu}=\{{\frac{E}{c}},-\overrightarrow{\mathbf{p}}\}$$
Four Potential : $$A^{\mu}=\{\phi,\overrightarrow{\mathbf{A}}\}$$$$A_{\mu}=\{{\phi},-\overrightarrow{\mathbf{A}}\}$$
Four Current : $$j^{\mu}=\{c\rho,\overrightarrow{\mathbf{J}}\}$$$$j_{\mu}=\{c\rho,-\overrightarrow{\mathbf{J}}\}$$
More Details click here[PDF]
Four Momentum : $$p^{\mu}=\{\frac{E}{c},\overrightarrow{\mathbf{p}}\}$$$$p_{\mu}=\{{\frac{E}{c}},-\overrightarrow{\mathbf{p}}\}$$
Four Potential : $$A^{\mu}=\{\phi,\overrightarrow{\mathbf{A}}\}$$$$A_{\mu}=\{{\phi},-\overrightarrow{\mathbf{A}}\}$$
Four Current : $$j^{\mu}=\{c\rho,\overrightarrow{\mathbf{J}}\}$$$$j_{\mu}=\{c\rho,-\overrightarrow{\mathbf{J}}\}$$
More Details click here[PDF]