This textbook presents an up to date  perspective on the fundamental elements of theoretical physics. It encompasses analytical mechanics, thermodynamics and statistical physics, special and general relativity, and non-relativistic quantum theory, thoroughly developing the necessary mathematical methods beyond standard calculus while striving to be as clear, explicit, and direct as possible. The exposition of the theory, both in the classical and quantum parts, is expanded and reworked compared to the first edition. In parallel with the formalism, which is explained in full detail,  several more experimental phenomena and techniques are included and discussed. Throughout, the emphasis is on the physical meaning of the theory, that is, the precise way in which the necessary experimental verification occurs or might occur in the future. With its comprehensive approach, rigorous mathematical treatments, and clear, physically oriented explanations of  principles and experiments, this textbook is an essential resource for advanced undergraduate and graduate students of physics, as well as a valuable reference for researchers.

Michele Cini is Full Professor in Physics at the University of Rome 'Tor Vergata', Italy, since 2000, having joined the university in 1988 as Associate Professor. Dr. Cini graduated in Physics cum laude from Pisa University in 1969. After a period as a research worker in the ENI group, he joined the National Research Council (CNR), "Instituto di Metodologie Avanzate Inorganiche", and was responsible for delivering two official courses for the degree in Physics at the University of L' Aquila. Dr. Cini has been the coordinator of two European ESPRIT projects and the prestigious Italian ‘prin’ project on Auger spectroscopy of magnetic systems of low dimensionality. He has also been a member of the scientific boards for various conferences. He has authored or co-authored about 150 papers as well as some previous Springer books.