The Cycle Space Over A Field or Commutative Ring
The construction of the integral cycle space can be carried out for any field, abelian group, or (most generally) commutative ring (with unity) R replacing the integers. If R is a field, the cycle space is a vector space over R with dimension m - n + c, where c is the number of connected components of G. If R is any commutative ring, the cycle space is a free R-module with rank m - n + c.
When R is an abelian group such a cycle may also be called an R-flow on G. Nowhere-zero R-flows for a finite abelian group R of k elements are related to nowhere-zero integral k-flows in Tutte's theory. The number of nowhere-zero R-cycles is an evaluation of the Tutte polynomial, dual to the number of proper colorings of the graph (Tutte, 1984, Section IX.4).
Read more about this topic: Cycle Space
Famous quotes containing the words cycle, space, field and/or ring:
“Oh, life is a glorious cycle of song,
A medley of extemporanea;
And love is a thing that can never go wrong;
And I am Marie of Roumania.”
—Dorothy Parker (1893–1967)
“Here were poor streets where faded gentility essayed with scanty space and shipwrecked means to make its last feeble stand, but tax-gatherer and creditor came there as elsewhere, and the poverty that yet faintly struggled was hardly less squalid and manifest than that which had long ago submitted and given up the game.”
—Charles Dickens (1812–1870)
“She is as in a field a silken tent
At midday when a sunny summer breeze
Has dried the dew and all its ropes relent,”
—Robert Frost (1874–1963)
“I started out very quiet and I beat Turgenev. Then I trained hard and I beat de Maupassant. I’ve fought two draws with Stendhal, and I think I had an edge in the last one. But nobody’s going to get me in any ring with Tolstoy unless I’m crazy or I keep getting better.”
—Ernest Hemingway (1899–1961)