Task & Data Analysis
Name of Dataset: Monopole Loops in QED
Author: Christian B. Lang

Files: 	"data_at_0.6.zar", "mono_at_0.6.zar", 
		"data_at_1.4.zar", "mono_at_1.4.zar"
Format: SC3 ZArchive

Scenario
The Story:
Quantum Electro Dynamics (QED) is the quantum field theory of charged particles and photons. For mathematical definiteness it is formulated on a space-time grid, i.e. a 4D lattice. The quantization is performed by summing over many such quantum field configurations, weighted by a probabiltiy factor depending on the field configuration. As a first step only the photon field is quantized. Each such configuration consists out of a set of 4 complex (unit modulus) numbers for each space-time point of the lattice, the so-called link variables. (This is our "data" files.)

This form of QED has two phases with a phase transition between. In the hot phase (large electromagnetic coupling e) there is confinement of all charges (only chargeless bound states are allowed) and an abundance of monopole loops [This are to be found in our "mono" data sets]. In the cold phase (small coupling e) the photons are massless and there are few if any monopoles. This is the physical phase realized in nature. 

Questions: Can one identify the phase transition, e.g. by „hearing“ the monopole density or other observables? Can one indeitfy the phase one is in for a specific coupling? Are such signals typical for sample configurations?

TaDa
The Task:
Mode:	Attention needed.{interactive, focus}
Type: 	discrete/procedural 
Style: 	exploration

The Information:
Level: intermediate

The Data:
Type:	interval	
Range:	Possible range of data:
QED Data: [0,1]
QED Monopole numbers: One of [-2, -1, 0, 1, 2]	
Organisation:	QED Data:
4-dimensional lattice (of equal lattice spacing a), each dimension has 10 sites,
at each site 4 entries giving the value of the positive direction of all possible links;
QED Monopole numbers:
same structure as above, but "dual lattice" (each of the four 3d cubes of plaquettes at a site in the data corresponds to the net flux = monopole number here )