Lagrangian approach to deriving the gravity equations in the new theory.
Ruslan Sharipov 1 ... 9 10 11 ... ru The Lagrangian approach to deriving various equations is associated with the name of Joseph Louis Lagrange. Detailed information about him can be found in Wikipedia . In mechanics and in physics his name is associated with the so-called "least action principle". According to this principle, the evolution of a physical system occurs in such a way that some integral over time turns out to take the smallest possible value. This integral is called the action integral. It is usually denoted by the letter S. The function L in the integral S is called the Lagrange function or the Lagrangian. In field theories it is itself an integral over spatial variables. In the spatial integral L we see a function denoted by the same letter, but in a calligraphic style. This is the Lagrangian density. It is represented as the sum of two terms: the Lagrangian density of the gravitational field and the Lagrangian density of matter. We will discuss the Lag