Multigrid renormalization
We combine the multigrid (MG) method with state-of-the-art concepts from the variational formulation of the numerical renormalization group. The resulting MG renormalization (MGR) method is a natural generalization of the MG method for solving partial differential equations. When the solution on a g...
| Main Authors: | , , |
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| Format: | Journal article |
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Elsevier
2018
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| _version_ | 1797057424952131584 |
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| author | Lubasch, M Moinier, P Jaksch, D |
| author_facet | Lubasch, M Moinier, P Jaksch, D |
| author_sort | Lubasch, M |
| collection | OXFORD |
| description | We combine the multigrid (MG) method with state-of-the-art concepts from the variational formulation of the numerical renormalization group. The resulting MG renormalization (MGR) method is a natural generalization of the MG method for solving partial differential equations. When the solution on a grid of N points is sought, our MGR method has a computational cost scaling as O(log(N)), as opposed to O(N) for the best standard MG method. Therefore MGR can exponentially speed up standard MG computations. To illustrate our method, we develop a novel algorithm for the ground state computation of the nonlinear Schrödinger equation. Our algorithm acts variationally on tensor products and updates the tensors one after another by solving a local nonlinear optimization problem. We compare several different methods for the nonlinear tensor update and find that the Newton method is the most efficient as well as precise. The combination of MGR with our nonlinear ground state algorithm produces accurate results for the nonlinear Schrödinger equation on N=1018grid points in three spatial dimensions. |
| first_indexed | 2024-03-06T19:36:09Z |
| format | Journal article |
| id | oxford-uuid:1f1ca839-0a96-4a0b-ac09-8cf9df8c2286 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T19:36:09Z |
| publishDate | 2018 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:1f1ca839-0a96-4a0b-ac09-8cf9df8c22862022-03-26T11:20:07ZMultigrid renormalizationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1f1ca839-0a96-4a0b-ac09-8cf9df8c2286Symplectic Elements at OxfordElsevier2018Lubasch, MMoinier, PJaksch, DWe combine the multigrid (MG) method with state-of-the-art concepts from the variational formulation of the numerical renormalization group. The resulting MG renormalization (MGR) method is a natural generalization of the MG method for solving partial differential equations. When the solution on a grid of N points is sought, our MGR method has a computational cost scaling as O(log(N)), as opposed to O(N) for the best standard MG method. Therefore MGR can exponentially speed up standard MG computations. To illustrate our method, we develop a novel algorithm for the ground state computation of the nonlinear Schrödinger equation. Our algorithm acts variationally on tensor products and updates the tensors one after another by solving a local nonlinear optimization problem. We compare several different methods for the nonlinear tensor update and find that the Newton method is the most efficient as well as precise. The combination of MGR with our nonlinear ground state algorithm produces accurate results for the nonlinear Schrödinger equation on N=1018grid points in three spatial dimensions. |
| spellingShingle | Lubasch, M Moinier, P Jaksch, D Multigrid renormalization |
| title | Multigrid renormalization |
| title_full | Multigrid renormalization |
| title_fullStr | Multigrid renormalization |
| title_full_unstemmed | Multigrid renormalization |
| title_short | Multigrid renormalization |
| title_sort | multigrid renormalization |
| work_keys_str_mv | AT lubaschm multigridrenormalization AT moinierp multigridrenormalization AT jakschd multigridrenormalization |