Recent content by A. Neumaier

??? How can the observer's brain solve the Schrödinger equation in real time?

It would mean that the Schrödinger equation (or whatever differential equation the state is assumed to satisfy) breaks down somewhere.

More interesting (and applicable to QFT) is the book A. Hobson, Fields and Their Quanta, 2024. It also gives a realist account, but in 4 dimensions!

See, e.g., the discussion in the last two sections of D. Wallace, The quantum theory of fields, and his Reading List in Philosophy of Quantum Field Theory. See also my own paper here.

I tried to define everything that is not in typical textbooks. For a single field ##\phi##, the N-point function is simply the map (and in fact for ##N>1## the distribution) defined by all quantum values $$W(x_1\ldots,x_N):=\langle\phi(x_1)\cdots\phi(x_N)\rangle.$$

A (classical or quantum) particle is a quantum field concentrated at each time in a small region of space. I tried to avoid the use of ''particle'' in any other way; if you see other uses, please let me know. Yes. Without interaction no measurement. And an interaction works in both directions...

It is finished for submission, and I put it online to get some early feedback before actually submitting it (in a few weeks). So the submitted version will perhaps be a little different.

Based on the thermal interpretation, I developed a quantum version of the classical, mechanical universe suggested by Laplace over 200 years ago. Abstract. The purpose of this paper is to propose a quantum version of the classical, mechanical universe suggested by Laplace over 200 years ago...

Possibly of interest: Albert, David Z. (2025) NOTES ON JACOB BARANDES’ VERSION OF QUANTUM MECHANICS. - Preprint, https://philsci-archive.pitt.edu/26777/

But his book is nearly as far as possible from the consensus textbook orthodoxy; see the last paragraph of p.20 in Beck's paper!

Orthodoxy is what is (by most textbooks) imparted to students when they have to learn quantum mechanics. That automatically excludes quantum field theory.

By the paper cited, we now know much better than we used to know....

Beck, G. (2025). How to be an orthodox quantum mechanic. https://arxiv.org/abs/2504.20597 From the abstract: From the conclusion:

Good theories (of which good models are anintegral part) have a high explanatory power, revealed by appropriate computations (that themselves don't have explanatory power) that can be matched with experiments. But neither theories nor calculations have causal power since they are just texts on...

I fully agree with that. But it has nothing to do with what I wrote. Calculations produce the predictions. But they have no causal physical power. What happens is not a result of calculations with models of physics, but of interactions of actual physical systems! To produce a decay (and...