The realization graph of a degree sequence with majorization gap 1 is Hamiltonian

Autor: Uri N. Peled, Srinivasa R. Arikati
Rok vydání: 1999
Předmět:
Zdroj: Linear Algebra and its Applications. 290:213-235
ISSN: 0024-3795
DOI: 10.1016/s0024-3795(98)10229-x
Popis: It is known that the degree sequences of threshold graphs are characterized by the property that they are not majorized strictly by any degree sequence. Consequently every degree sequence d can be transformed into a threshold sequence by repeated operations consisting of subtracting I from a degree and adding 1 to a larger or equal degree. The minimum number of these operations required to transform d into a threshold sequence is called the majorization gap of d . A realization of a degree sequence d of length n is a graph on the vertices 1, …, n , where the degree of vertex i is d i . The realization graph %plane1D;4A2;( d ) of a degree sequence d has as vertices the realizations of d , and two realizations are neighbors in %plane1D;4A2;( d ) if one can be obtained from the other by deleting two existing edges [ a, b ], [ c, d ] and adding two new edges [ a, d ]; [ b, c ] for some distinct vertices a, b, c, d . It is known that %plane1D;4A2;( d ) is connected. We show that if d has a majorization gap of 1, then %plane1D;4A2;( d ) is Hamiltonian.
Databáze: OpenAIRE