The Multiplicative Quantum Adversary
| dc.creator | Spalek, Robert | |
| dc.date | 2007-03-26 | |
| dc.date | 2007-04-25 | |
| dc.date.accessioned | 2026-07-07T07:58:18Z | |
| dc.date.available | 2026-07-07T07:58:18Z | |
| dc.description | We present a new variant of the quantum adversary method. All adversary methods give lower bounds on the quantum query complexity of a function by bounding the change of a progress function caused by one query. All previous variants upper-bound the_difference_ of the progress function, whereas our new variant upper-bounds the_ratio_ and that is why we coin it the multiplicative adversary. The new method generalizes to all functions the new quantum lower-bound method by Ambainis [Amb05, ASW06] based on the analysis of eigenspaces of the density matrix. We prove a strong direct product theorem for all functions that have a multiplicative adversary lower bound. | |
| dc.description | 15 pages, v2: removed an incorrect claim, v3: cleaned up, commented better, added stronger bound for OR | |
| dc.identifier | https://arxiv.org/abs/quant-ph/0703237 | |
| dc.identifier | http://arxiv.org/abs/quant-ph/0703237 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/127958 | |
| dc.subject | Quantum Physics | |
| dc.title | The Multiplicative Quantum Adversary | |
| dc.type | text |