Polyakov Action - Relation With Nambu-Goto Action

Relation With Nambu-Goto Action

Writing the Euler-Lagrange equation for the metric tensor one obtains that:

Knowing also that:

One can write the variational derivative of the action:

where which leads to:

If the auxiliary worldsheet metric tensor is calculated from the equations of motion:

and substituted back to the action, it becomes the Nambu-Goto action:

However, the Polyakov action is more easily quantized because it is linear.

Read more about this topic:  Polyakov Action

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