We must regard the Schrodinger equation not as showing that matter also behaves like a wave. That is so archaic that I want to throw up.
No. The Schrodinger equation was the first Quantum Field Theory. The mathematical "waves" it produces is merely a reflection of the mathematical tools we humans have available that can describe how physical processes are probabilistic and not uni-deterministic.
But this is nothing new. The probabilistic interpretation of the wave function is 100 years old, and it is about time to take the idea seriously.
The Dirac Equation is Relativistically Invariant.
Proof attached.
Proving the Relativistic Energy-Momentum relation, the hard way and the easier way.