Eisberg Robert-Martin. Fundamentals Of Modern Physics 1964

Textbook in PDF format

This book is highly regarded as a foundational text for university students studying physics, with many reviewers calling it a "classic" in the field.
The book covers the essential fundamentals of modern physics, including relativity and quantum mechanics, providing detailed explanations and mathematical proofs. The core basics of the subject haven't changed, making this older text as relevant now as when it was first published