Can Szego Projectors Be Interpreted as POVM in von Neumann Density Context?

Ssnow
Science Advisor
Messages
573
Reaction score
182
I want to ask if it is wrong to interpret the von Neumann density in a '' functional sense'' as a szego projector Hilbert spaces?
thks
 
Physics news on Phys.org
I don't know what they are, but since density matrices are, by definition, defined on Hilbert spaces, that would seem rather difficult unless you change the concept in some way.

In case you haven't seen it here is the exact definition, which is part of the Born Rule

There exists a positive operator of unit trace, P, called the state of the system, such that if O is an observable, E(O), the expected outcome of the observation, is E(O) = Trace (PO).

P is also called the density matrix, but its not my preferred term.

As to why its true check out post 137:
https://www.physicsforums.com/threads/the-born-rule-in-many-worlds.763139/page-7

Thanks
Bill
 
Szego projectors are orthogonal projectors from the Hardy space H(X) to L^2 (an equivariant component), It seems that all POMV requirements are satisfied but not the condition on the trace that bust be 1 ... now my question is if I can interpret these Szego projectors (that in general are not matrices but more similar to oscillatory integrals (his kernel)) as a family of POVM that respect the Born rule.
Thank you for the link and your answer ...

Hi,
Ssnow
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!

Similar threads

Replies
2
Views
1K
Replies
4
Views
2K
Replies
2
Views
2K
Replies
3
Views
2K
Replies
7
Views
3K
Replies
23
Views
3K
Back
Top