Recent comments from SciRate

There was a discussion about a previous paper of Joux (with a weaker result) on this blog post:
https://rjlipton.wordpress.com/2013/05/06/a-most-perplexing-mystery

"Of course, ghosts do not exist..."
seems like a rather strange assumption in order to define "ghost world".

:-)

Funny-looking zebra in Fig 1(a)

And here is a question on cstheory.SE about this paper: http://cstheory.stackexchange.com/q/18134/1542

Nice paper indeed.

@Min-Hsiu Hsieh: for a more fair comparison, you should normalize by the total number of scirate users. Anyway, it's great to see that this number is growing quickly!

I thought this was long overdue. Thanks!

I'm confused. Presumably they are not claiming they have a counterexample to Bell's theorem. If not that, what does it mean to simulate Bell violations without quantum resources (assuming a Bell-local model)?

Let's go with the probabilistic version of the CHSH inequality,

(1/4)(p(a_0=b_0)+p(a_0=b_1)+p(a_1=b_0)+p(a_1!=b_1))<=(3/4).

This probability will clearly not exceed the 3/4 bound regardless of what values you assign to a_0,b_0,a_1,b_1.

Indeed, if you choose the variables to take values in {

...(continued)

They cite http://arxiv.org/abs/0908.3023 but I don't see how they address its criticism of the idea of making computational use of nonlinearity.

In particular, they respond to the paper by saying "In particular we
take the common view that if pure states are deterministically prepared and insert

...(continued)

Great title! I'm not convinced it's simpler, but it's nice to see an unfamiliar take on a familiar topic.

oh man...

There is something funny about that journal (and also many others). The landing page for the journal is here:
http://naturalspublishing.com/show.asp?JorID=16&pgid=0

It takes some clicking to get to the actual article(s) published in the journal. Much more prominent are the instructions to auth

...(continued)

The original quantum Pagerank paper used adiabatic evolution, and this one uses the Szegedy walk. I wonder how the methods compare.

Another thing I'd like someone to figure out at some point is whether these can be done using resources scaling like poly log(# vertices) for power law graphs. T

...(continued)

Han-Hsuan, I think Dave is using the term "Bell inequality" to refer more generally to entanglement witnesses that are can be constructed from correlated local measurements.

In the multipartite setting, these witnesses distinguish the entangled state from any tripartite separable state. Here's t

...(continued)

I'll answer anyway. :) This was written about in:
http://arxiv.org/abs/quant-ph/9604028

Their simulation produces outputs that are not +1/-1 valued.

Here is a toy version of their argument.
In normal CHSH, Alice chooses a_0, a_1 and Bob chooses b_0, b_1, with the goal of maximizing
a_0 b_0 + a_0 b_1 + a_1 b_0 - a_1 b_1.

Normally we have the constraint |a_i|, |b_i| <= 1.
Then t

...(continued)

I think that's basically right.

To be clear, they didn't do the "multiply by sqrt(2)" thing I said, but rather replaced +-1-valued observables with complex numbers. Still it does seem to miss the whole point of Bell's Theorem.

It's nice that there's a discussion of why discord is an important thing to look at. However, all of the examples are cases where the difference between zero and nonzero discord is interesting, and not examples of where *quantifying* discord (given that it is nonzero) tells us something useful.

This paper reads as though Dyakonov stopped reading the literature after the original FTQC paper by Aharonov and Ben-Or. In discussions a few months ago, I mentioned the following papers that address his criticisms:

http://arxiv.org/abs/quant-ph/0504218
http://arxiv.org/abs/1207.6131
http://ar

...(continued)

Actually, I recklessly submitted this to a machine learning conference, with some open review system. So, we will soon see some opinion there:
http://openreview.net/iclr2013

Thanks for the comment Random Reader. The assumption that H_I is bounded is in fact not necessary for any of our derivations. The bound that troubled you under Eq. (12) has been replaced in v2 of the paper with a new and tighter bound, which essentially uses only the properties of the bath correlati

...(continued)

This journal lists me as a member of their editorial board; I have never been contacted by them and certainly haven't agreed to serve in this role, nor do I have any such intention. The two "Editors in Chief" have told me that the same holds for them.

Unless I'm missing something, the editorial board information for "Quantum Information Review" now seems to have disappeared...

Nice paper! Gives agood overview of what id possible and what is not with respect to bit commitment from relativistic assumptions. I guess it would be natural to reference this paper by Crepeau and Co. as well: http://dx.doi.org/10.1007/978-3-642-25385-0_22

I wonder if the spin-boson bath example presented on p. 10 of this preprint is internally consistent with the proposed internally-consistent derivation. The interaction Hamiltonian H_I operator in (61) for the spin boson model is neither bounded nor is it trace class, thus the trace and operator no

...(continued)

You might consider citing this paper by Ambainis et al. :
http://arxiv.org/abs/quant-ph/0003136

This result is very encouraging for experimentalists dealing with CV clusters. While the various thresholds are quite high with respect to current squeezing technologies, the mere existence of a near-feasible threshold gives us something tangible to work towards.

Thanks for keeping CV clusters re

...(continued)

Testing out the comments.