Theoretical physics. Field theory

The book offered to the reader by the outstanding Russian physicist A.A. Eichenwald (1863-1944) is dedicated to the field of theoretical physics known as field theory. The book consists of three chapters. The first chapter contains the most important rules of vector calculus, understanding the information presented in it is essential for grasping the vector notations used in all physics manuals. The chapter describes vector addition and subtraction, vector multiplication, as well as derivatives and integrals in physics. The second chapter covers the fundamentals of field theory, discussing scalar fields, potential vector fields, vortical, flat, and variable fields. The third chapter provides brief information on tensors, with the final section presenting the general analytical theory of tensors in multidimensional space, which was influenced by Einstein's theory of relativity. This book, in previous editions, formed the first part of A.A. Eichenwald's classic work "Theoretical Physics," however, it can be viewed as a completely independent work. The presentation is structured in a way that does not require the reader to have extensive knowledge of mathematics; a basic understanding of differential and integral calculus is sufficient to comprehend the material. The book will be useful not only to physicists but also to engineers - electrical and hydraulic engineers. It can serve as an excellent guide for students of physics and mathematics departments at universities when studying the course of theoretical physics.