What is the Nolting spin product of graphs?

[LagrangeEuler]

Look at the page 256. relation (6.93).
http://books.google.rs/books?id=vrc...page&q=Nolting spin product of graphs&f=false

What is even vertex? Can you explain me in term of graphical representation of spin product. Are those products in the bottom of page 256 is equal to zero?

 

[DrDu]

An even vertex is a vertex whose order is an even number (2 or 4). Yes, the spin products in Fig. 6.13 all vanish according to the definition.

 

[LagrangeEuler]

And what is with $\upsilon^0$ term? Is that like vacum?

 

[DrDu]

And what is with $\upsilon^0$ term? Is that like vacum?

What's the problem with it? You want to have the system to have a partition function in the case J=0, too, don't you?

 

[LagrangeEuler]

Yes. Tnx.