ABSTRACT
The scalar field provides the simplest example of what has been discussed so far. In general, we can choose: https://www.w3.org/1998/Math/MathML" display="block"> L = 1 2 ( ∂ μ ϕ ) ( ∂ μ ϕ ) − 1 2 m 2 ϕ 2 − V ( ϕ ) https://www.w3.org/1999/xlink" xlink:href="https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003436263/11a1814b-c2ab-4d89-be15-80efb520b7b3/content/math4_1.tif"/>
