CONCEPTS IN THEORETICAL PHYSICS MAIN TOPICSEquations in physics. Simplicity and chaos. Invariances, constants, and dimensions. Action principles. Quantum mechanics. Statistical physics. General relativity. Cosmology. Elementary particles.Note: This is not a normal course. It is more akin to a seminar, introducing essential concepts in theoretical physics. LECTURE NOTESConcepts in Theoretical Physics, by J. Barrow, 2019, University of Cambridge.