
Review the metric tensor, its line element, inverse metric, determinant relations, and Christoffel symbols. Derive the Einstein field equations and explore the weak-field metric expansion linking to Newtonian gravity.
Explain the invariant in a centrally symmetric gravitational field in general relativity, described in spherical coordinates with a function of r and time, preserving symmetry while including angular terms carefully.
Transform coordinates to set A zero and K minus R squared, then derive the metric tensor from the invariant and compute Christoffel symbols and Ricci tensor with Matlab.
Learn to compute Christoffel symbols from a diagonal metric by deriving the inverse metric and partial derivatives, and verify results with Matlab.
Compute Christoffel symbols and the Ricci and Einstein tensors in Matlab using the symbolic toolbox. Set up the metric, define coordinates, derive derivatives, and verify results against the Christoffel expressions.
Rewrite the mixed Einstein tensor terms, analyze the extensor G AlphaBeta and its matrix components, and define sigma terms, then relate the vacuum setting to the energy-momentum tensor.
this lecture derives the stress-energy tensor for a macroscopic body using the four-velocity, defines energy density and pressure, and shows the rest-frame diagonal form.
The lecture derives exact field equations for a centrally symmetric vacuum gravitational field, setting stress-energy components to zero and analyzing lambda and its derivatives to show no extra information arises.
Derives the vacuum field equations for a centrally symmetric gravitational field, yielding the Schwarzschild metric and Schwarzschild radius, and shows alignment with Newton's law at large distances.
Explore how the Schwarzschild radius shapes the metric and time dilation near massive bodies, reveals curvature effects on distances, and connects to Mercury’s perihelion shift, light bending, and gravitational waves.
Derive the relativistic correction to planetary orbits using the Schwarzschild metric and conserved quantities, and compute the Mercury perihelion advance from energy and angular momentum.
Explain how general relativity predicts light deflection by gravity, deriving the sun’s deflection angle using the Schwarzschild metric and Fermat’s principle, yielding alpha = 4 GM/(B c^2).
Relate the Schwarzschild radius to energy balance, derive r_s = 2GM/c^2, and discuss relativistic corrections affecting stable orbits and light's different critical radius near 3GM/c^2.
Derive the relativistic Hamilton-Jacobi equation from the action and Hamiltonian for a massive object, bridging special and general relativity with covariant derivatives and metric for light bending and perihelion shift.
Show how the action stays invariant under canonical transformations, use generating functions to link coordinates and momenta, and relate constants like energy and angular momentum to planetary trajectories.
Derive the relativistic correction to Mercury's orbit in a central Schwarzschild field by using conserved energy and angular momentum, the metric, and an orbital integral to obtain the trajectory.
Compute the relativistic corrections to Mercury’s orbit by expanding the trajectory in powers of RG over R, compare earth’s and sun’s cases, and outline Matlab implementation for higher-order terms.
Compute a Maclaurin series of a function in Matlab with symbolic variables and a third-order truncation. Substitute sigma one to obtain the series used to derive Mercury's perihelion advance.
Derives the relativistic correction to Mercury's perihelion by expanding the radial action and isolating the 1 over r^2 term, yielding the advance delta phi per revolution.
Calculate the delta phi correction for the advance of Earth and Mercury perihelion using eccentricity and the semi-major axis, and express results in arc seconds per century.
Explore how light bends in a center-symmetric gravitational field by applying the Hamilton-Jacobi framework for massless photons, deriving the light-ray trajectory and the leading relativistic corrections.
Compute relativistic corrections to the bending of light by reformulating the integral and extracting the deflection angle, showing delta phi relates to the gravitational parameter R_G for large distances.
Derive gravitational waves from the field equations in a weak vacuum, showing metric perturbations propagate as waves at the speed of light.
This course is a sequel to: "Mathematical Intuition behind Special and General Relativity". The knowledge of tensors is a mathematical prerequisite.
The following concepts are recalled at the beginning of the course: the Ricci tensor, metric tensor, Christoffel symbols, Einstein's field equations. All these concepts will then be used to make the same mathematical predictions that were made by Einstein and other physicists in the 20th century. These predictions served to establish observational evidence for the theory of general relativity. Two of these tests were proposed by Einstein in 1915, and concerned the unexplained precession of the perihelion of Mercury, as well as the bending of light in gravitational fields.
Under Newtonian physics, a two-body system consisting of an object (e.g. planet) orbiting a spherical mass (e.g. the sun) would trace out an ellipse with the system's center of mass located at one of the two foci. The point of closest approach, called the perihelion, is fixed, but Mercury deviates from these predictions by showing a precession which is not predicted by a Newtonian system, not even taking into account the presence of other planets. This anomalous advance of the perihelion of Mercury's orbit was first recognized in the 19th century as a problem in celestial mechanics. Analysis of available observations showed that the actual rate of the precession disagreed from that predicted from Newton's theory. Einstein showed that general relativity agrees closely with the observed amount of perihelion shift. This powerful factor motivated the adoption of general relativity.
Also, Einstein predicted that starlight would bend around a massive object; in particular, he calculated the correct value for light bending: 1.75 arcseconds for light that skirts the edge of the sun. The observations were performed by Arthur Eddington and his collaborators during a total solar eclipse in 1919. The result was considered spectacular and made the front page of most major newspapers. It made Einstein and his theory of general relativity world-famous.
In the course, we will also derive gravitational waves from Einstein field equations in vacuum. In February 2016, the Advanced LIGO team announced that they had directly detected gravitational waves from a stellar binary black hole merger, with additional detections announced in June 2016, June 2017, and August 2017.
This course was inspired by Landau and Lifschitz's volume two: The Classical Theory of Fields.