What major assumption did de broglie and schrodinger make about the motion of tiny particles?

De Broglie and Schrödinger assumed that tiny particles, such as electrons, exhibit wave-particle duality, meaning they can behave both as particles and waves. This led to the idea that particles have associated wavelengths, which can be described mathematically by wave functions. They proposed that the behavior of these particles could be modeled using wave mechanics, allowing for the prediction of their probabilistic positions and momenta. This fundamental shift laid the groundwork for quantum mechanics.