P(X, phi) scalar field theory
= P(X, phi) scalar field theory
{c}
{title2=$P(X,\phi)$ theory}
A $P(X,\phi)$ scalar theory has Lagrangian density $P$ depending on the field and $X=-g^{\mu\nu}\partial_\mu\phi\partial_\nu\phi/2$. It includes canonical scalar theory and models with noncanonical kinetic interactions.
A <k-essence> model uses noncanonical kinetic terms for cosmological acceleration; a general <P(X, phi) scalar field theory> need not have that application.