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| Content Provider | Springer Nature Link |
|---|---|
| Author | Dyer, Martin Goldberg, Leslie Ann Jerrum, Mark |
| Copyright Year | 2010 |
| Abstract | We consider the complexity of counting homomorphisms from an r-uniform hypergraph G to a symmetric r-ary relation H. We give a dichotomy theorem for r > 2, showing for which H this problem is in FP and for which H it is #P-complete. This generalizes a theorem of Dyer and Greenhill (2000) for the case r = 2, which corresponds to counting graph homomorphisms. Our dichotomy theorem extends to the case in which the relation H is weighted, and the goal is to compute the partition function, which is the sum of weights of the homomorphisms. This problem is motivated by statistical physics, where it arises as computing the partition function for particle models in which certain combinations of r sites interact symmetrically. In the weighted case, our dichotomy theorem generalizes a result of Bulatov and Grohe (2005) for graphs, where r = 2. When r = 2, the polynomial time cases of the dichotomy correspond simply to rank-1 weights. Surprisingly, for all r > 2 the polynomial time cases of the dichotomy have rather more structure. It turns out that the weights must be superimposed on a combinatorial structure defined by solutions of an equation over an Abelian group. Our result also gives a dichotomy for a closely related constraint satisfaction problem. |
| Starting Page | 605 |
| Ending Page | 633 |
| Page Count | 29 |
| File Format | |
| ISSN | 10163328 |
| Journal | Computational complexity |
| Volume Number | 19 |
| Issue Number | 4 |
| e-ISSN | 14208954 |
| Language | English |
| Publisher | Birkhäuser-Verlag |
| Publisher Date | 2010-12-06 |
| Publisher Place | Basel |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Dichotomy hypergraph partition functions Algorithm Analysis and Problem Complexity Computational Mathematics and Numerical Analysis |
| Content Type | Text |
| Resource Type | Article |
| Subject | Theoretical Computer Science Computational Theory and Mathematics Computational Mathematics |
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