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» New Plain-Exponential Time Classes for Graph Homomorphism
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CSR
2009
Springer
13 years 10 months ago
New Plain-Exponential Time Classes for Graph Homomorphism
A homomorphism from a graph G to a graph H (in this paper, both simple, undirected graphs) is a mapping f : V (G) → V (H) such that if uv ∈ E(G) then f(u)f(v) ∈ E(H). The pro...
Magnus Wahlström
DM
2006
107views more  DM 2006»
13 years 3 months ago
On a new reformulation of Hadwiger's conjecture
Assuming that every proper minor closed class of graphs contains a maximum with respect to the homomorphism order, we prove that such a maximum must be homomorphically equivalent ...
Reza Naserasr, Yared Nigussie
CORR
2010
Springer
130views Education» more  CORR 2010»
13 years 3 months ago
Dichotomy for tree-structured trigraph list homomorphism problems
Trigraph list homomorphism problems (also known as list matrix partition problems) have generated recent interest, partly because there are concrete problems that are not known to...
Tomás Feder, Pavol Hell, David G. Schell, J...
EJC
2006
13 years 3 months ago
Homomorphism bounded classes of graphs
A class C of graphs is said to be H-bounded if each graph in the class C admits a homomorphism to H. We give a general necessary and sufficient condition for the existence of boun...
Timothy Marshall, Reza Nasraser, Jaroslav Nesetril
ICALP
2009
Springer
14 years 3 months ago
Counting Subgraphs via Homomorphisms
We introduce a generic approach for counting subgraphs in a graph. The main idea is to relate counting subgraphs to counting graph homomorphisms. This approach provides new algori...
Omid Amini, Fedor V. Fomin, Saket Saurabh