An overview of the expanding universe, the Friedmann equations, and the Big Bang theory.
Unlike textbooks that dive immediately into complex Riemannian geometry, Ohanian and Ruffini take a "physics-first" approach.
Detailed review of the inverse-square law, gravitational potential, and tidal forces. ohanian gravitation and spacetime pdf
Hans Ohanian, an American physicist, presented a distinct approach to understanding gravitation and spacetime in his 1988 paper, "Gravitation and Spacetime." Ohanian's work is based on the idea that gravity is not a curvature of spacetime caused by mass and energy, as in general relativity, but rather a manifestation of the quantum vacuum.
Long before the LIGO discoveries, Ohanian provided a lucid introduction to the linearization of field equations. This section is particularly valuable for students trying to understand how ripples in spacetime propagate. 4. Relativistic Astrophysics An overview of the expanding universe, the Friedmann
Ohanian’s coverage of frame-dragging and the Lense-Thirring effect is particularly praised—clear, physical, and connected to Maxwell-like analogies.