Hi everyone,
I'm trying to derive the equations of motion of a scalar field with a potential V(ϕ),
S:=−∫√−g(12gμν∂μϕ∂νϕ+V)d4x; however when I compute the variational derivative of the action with respect to ϕ the potential does not appear (due to property V::Depends::{x}
, only allow to make objects implicitly dependent on the coordinates). Is there any property in Cadabra which Makes an object explicitly dependent on other objects, like V(ϕ)?
Thank you !!