A quick introduction to gauge theories []
An introduction to gauge theories for those already familiar with quantum mechanics. It covers the broken symmetry, the Higgs mechanism and the Weinberg-Salam model.

Relativity: a quick introduction []
A quick introduction to Special Relativity with a derivation of E=mc2.

Light-travel time effects in binary systems []
The light-travel time effects for a pulsating star (or a close binary) in a binary system are calculated.

Mach's Principle and Evolution of the Universe []
Within the framework of Mach's principle and of D.W. Sciama's physical interpretation of it, a quantitative evaluation of the inertial mass as a function of the density of the universe and of the epoch is obtained. The calculation is somewhat similar to the solution of Olbers's paradox. The result shows that the inertial mass varies as the universe expands except for a flat, Euclidean universe. This leads to insights on the Principle of Equivalence.

Stellar structure []
The equations that describe a polytropic star structure are derived.

Pulsating stars I: Differential equation []
The differential equation of a radially pulsating star is derived.

Pulsating stars II: Solutions at constant density []
The differential equation for a radially pulsating star is solved for a constant density.

Pulsating stars III: Polytropic model []
The solutions to the differential equation of a radially pulsating star are presented for a polytropic model.

Binary systems: orbital period and mass transfer []
The equations for the relation between the orbital period change of a binary system and the mass transfer are explicited.