A. Neumaier's latest activity

yes, and a very poor one in most cases, except when a system is nearly in the ground state (as for molecules in much of quantum...

In the present paper I don't use the term q-expectation. All terminology used in the paper is explained there. The Born rule is derived...

In the Stern-Gerlach experiment discussed on p.15, <P_+> and <P_-> are the propensity for a single silver atom to appear on the left or...

Your question is ill-posed. Since this hydrogen atom interacts with other atoms, it is in a mixed state, obtained from the state of this...

No. I am using the standard unitary formalism of QM applied to QFT for the whole universe. Then I draw consequences for it's physical...

For a physical system in a pure state ##\psi##, the matrix elements ##\langle X \rangle=\psi^*X\psi## may be regarded as providing its...

This link now contains a significantly expanded version, ready for publication. New additions are (in addition to other small...

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

One could argue that if the electron does not exist between measurements, then it cannot be described by a state or wave-function (or...

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...

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...

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...

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...

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...