A Spin networks with different intertwiners

Heidi
Messages
420
Reaction score
40
Hi Pfs
Spin networks are defined by the way their links and their nodes are equipped with SU(2) representations and intertwiners.
Could you give an example of two different spin networks with the same number of nodes, links between them, the same coloring of the links (and their orientations) but have different intertwiners?
I would like to see how to assign squarable complex valued functions to them. how the intertwiners contract with the links.
thanks
 
Physics news on Phys.org
if i take the tensor product of two half integer SU(2) representation on 2 dimensional Hilbert space, i get a 4 dimensional matrix with
##1/2 \otimes 1/2 = 0 + 1## and if i tensor it by it self i get the (0 + 1) + (1 + 0 + 1 + 2) representation with dimension 4 + 12 = 16. we see that 0 appears twice so there are two intertwiners. How do they act in the four valent node?
and what is the problem with the latex formula?
 
Not an expert in QM. AFAIK, Schrödinger's equation is quite different from the classical wave equation. The former is an equation for the dynamics of the state of a (quantum?) system, the latter is an equation for the dynamics of a (classical) degree of freedom. As a matter of fact, Schrödinger's equation is first order in time derivatives, while the classical wave equation is second order. But, AFAIK, Schrödinger's equation is a wave equation; only its interpretation makes it non-classical...
I asked a question related to a table levitating but I am going to try to be specific about my question after one of the forum mentors stated I should make my question more specific (although I'm still not sure why one couldn't have asked if a table levitating is possible according to physics). Specifically, I am interested in knowing how much justification we have for an extreme low probability thermal fluctuation that results in a "miraculous" event compared to, say, a dice roll. Does a...
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
Back
Top