Alexander P. Yefremov

Prof. Alexander P. Yefremov, Dr. Sci., is the head of the Chair of Physics, director of the Institute of Gravitation and Cosmology, and Vice-Rector for academic affairs of Peoples’ Friendship University of Russia (RUDN University).
His major is Theoretical Physics; his scientific interests are the theory of gravitational field, celestial mechanics, quantum mechanics, and the math of hypercomplex numbers.
He is the author of more than 150 papers, 4 monographs, and 3 textbooks. His main research achievements in the theoretical physics are suggestion of the “Quaternion version of the theory of relativity” (1996-2008), the “Conic gearing image of a complex number” (2011), and the “General theory of a particle’s mechanics” (2012-2015). He is also the author of original math instruments applied to operate a spacecraft (see recently published Chapter “Fractal pyramid: a new math tool to reorient and accelerate a spacecraft” in the book” Space Flight”, DOI: 10.5772/intechopen.69789).