# Quick question, index notation, alternating tensor.

1. Dec 26, 2013

### binbagsss

Q) I am using index notation to show that ε$^{0123}$=-1 given that ε$_{0123}$=1.

The soluton is:

ε$^{0123}$=g$^{00}$g$^{11}$g$^{22}$g$^{33}$ε$_{0123}$=-ε$_{0123}$

where g$_{\alpha\beta}$ is the metric tensor.

I am struggling to understand the last equality.

Many thanks for any assistance.

2. Dec 26, 2013

### Staff: Mentor

g00=-1, correct? Really, η00=-1.