On Wednesday, August 7, 2019 at 1:03:44 PM UTC-5, Brent wrote: > > > > On 8/7/2019 1:08 AM, Philip Thrift wrote: > > On Tuesday, August 6, 2019 at 5:29:04 PM UTC-5, Brent wrote: >> >> >> >> On 8/6/2019 11:25 AM, Philip Thrift wrote: >> >> >> >> On Tuesday, August 6, 2019 at 1:00:23 PM UTC-5, Brent wrote: >>> >>> >>> >>> On 8/6/2019 6:38 AM, Bruno Marchal wrote: >>> >>> If the QC does its task effectively, the output basis qbits will be put >>> into definite states, >>> >>> >>> Relatively to the observer, but in the global state, the observer will >>> inherit the superposition state, by linearity of the tensor products and of >>> the evolution. >>> >>> >>> In something like Shor's algorithm there is only one final state with >>> non-vanishing probability. Yet this is the kind of algorithm that Deutsch >>> cites as proving there must be many worlds. >>> >>> Brent >>> >> >> >> >> That there is a multiplicity of *somethings* >> >> https://en.wikipedia.org/wiki/Multiple_histories >> >> is the basis for all semantics of quantum computing (by computer >> scientists) that I have ever seen. >> >> >> Same for classical computation...there are lots of states or functions. >> Did anyone think there had to be multiple worlds for the computer to work? >> >> Brent >> > > > > There is classical parallel hardware, e.g. made with multiple processors. > > Parallelism in quantum computers is achieved by parallel "worlds" or > "paths": > > Quantum Path Computing > - https://arxiv.org/abs/1709.00735 > > Quantum circuit dynamics via path integrals: Is there a classical action > for discrete-time paths? > - https://iopscience.iop.org/article/10.1088/1367-2630/aa61ba > > > But as you note with scare quotes, calling those "worlds" or "paths" is > just metaphorical. They are not worlds you can visit or paths you can > take. They are aspects of mathematical abstractions. > > Brent > > > A “problem of time” in the multiplicative scheme for the n-site hopper > Fay Dowker, Vojtˇech Havlicek, Cyprian Lewandowski, and > Henry Wilkes > - > https://pdfs.semanticscholar.org/39d9/11e25b835ce8d34910c0a9e02f22ef8d4c41.pdf > "Quantum Measure Theory (QMT*) is an approach to quantum mechanics, > based on the path integral, in which quantum theory is conceived of as a > generalized stochastic process." > * > https://pdfs.semanticscholar.org/bfda/1caa5afbbd9e2d6dcff5456325b60b64b909.pdf > > The sum-over-histories formulation of quantum computing > - https://arxiv.org/abs/quant-ph/0607151 > > @philipthrift > >
If a multiplicity of somethings isn't present in a quantum computer, then how does the speedup occur? @philipthrift -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/d683b679-e81b-40cb-828e-cd950d687de9%40googlegroups.com.
