Heaviside and von Neumann are probably not eligible. There's no Nobel Prize in math, which more or less rules out von Neumann. Heaviside developed a lot of tools still used in electrical engineering, but there isn't a Nobel Prize in that either. And Heaviside's work was notorious for its lack of rigor, which caused him to lose out on a lot of recognition.
But Shannon... information theory is an Important Tool in physics. It led Stephen Hawking to predict Hawking Radiation, which was important for understanding black holes. And it has a lot of other uses in physics as well. He'd be eligible, I think. But it's still a marginal case; information theory, itself, isn't physics. It's still math.
>Heaviside developed a lot of tools still used in electrical engineering, but there isn't a Nobel Prize in that either.
For good or for bad, electrical engineering work has won Nobel prizes: Transistors, integrated circuits, etc. These were inventions and did not provide insights into physics.
Did not Neumann put quantum mechanics on a firmer mathematical footing?
Heaviside reformulated Maxwells work in electodynamics into the form it has been used ever since, and had major role in developing vector analysis which is like indispensable in Physics now.
