Recent comments from SciRate

I think "quantum advantage" instead of "quantum supremacy" is a no-brainer. I was not aware of the objection to "ancilla". The connotations of "ancilla" are less obvious and Karoline has to dust off some Roman history to make the case for replacing "ancilla". To me, this makes the replacement of

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Dear Joel,

We are indeed "fielded questions like this a hundred times over." That's why I try to write some papers to allay it: It never works. Anyway, here's one example that's relevant for your queries: https://scirate.com/arxiv/1601.04360. My own view is that taking first-person elements

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Dear Ruediger,

Thanks for your prompt and cordial response. I hope you'll forgive the absence of address and signoff in my previous comment, my excitement got the better of my internet etiquette.

I think I understand what you are saying. The notion is that by making a statement like "a rubidiu

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Dear Joel,

Thank you for this question about Fuchs's paper. As you suggest, if taken out of context, the tenet "My probabilities cannot tell nature what to do" is a little mystifying. No serious thinker should believe that *his* probabilities tell nature what to do. The actual content of the tene

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At the end of page 19, section 2.2 you introduce the tenet

"My Probabilities Cannot Tell Nature What To Do"

Can you elaborate on why it is necessary to include this tenet in QBism? Or more precisely, in what way is QBism unique in having this tenet? Are there any serious thinkers that are pro

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Dear Michel,

1. It was just a goofy thing that I thought would get the readers to smile. But Wolfgang Pauli did have quite a mystical interest in 137 precisely because of its connection to the fine structure constant. This is documented in quite a number of places; the book by Suzanne Gieser,

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Dear Christopher,

1. Could you comment on the connection to the fine structure constant in footnote 15 in which you write "Implicit in it is the number 137!"?

2. Would the Qbism philosophy be destroyed by restricting to IC's instead of SICs as in https://scirate.com/arxiv/1704.02749#807?

Thanks.

what's the value for $n$ of n-grams?

Bravo!

I've posted a public referee report on this paper here: https://nbviewer.jupyter.org/github/csferrie/openreviews/blob/master/arxiv.1703.10743/arxiv.1703.10743.ipynb

This paper [appeared][1] in February 2016 in the peer reviewed interdisciplinary journal Chaos by the American Institute of Physics (AIP).

It has been reviewed publicly by amateurs both [favorably][2] and [unfavorably][3]. The favorable review took the last sentence of the abstract ("These invalid

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http://ibiblio.org/e-notes/Chaos/intermit.htm

Great note. I real like the two end-sentences: "Of course, any given new approach to a hard and extensively studied problem has a very low probability to lead to a direct solution (some popular accounts may not have emphasized this to the degree we would have preferred). But arguably, this makes the

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Interesting to start getting perspectives from actual end users. But this does focus massively on quantum annealing, rather than a 'true' universal and fault-tolerant QC.

It must feel good to get this one out there! :)

First of all, thanks to all for helping to clarify some hidden points of our paper.
As you can see, the field norm generalizes the standard Hilbert-Schmidt norm.
It works for SIC [e.g. d=2, d=3 (the Hesse) and d=8 (the Hoggar)].

The first non-trivial case is with d=4 when one needs to extend th

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Okay, I see the resolution to my confusion now (and admit that I was confused). Thanks to Michel, Marcus, Blake, and Steve!

Since I don't know the first thing about cyclotomic field norms... can anybody explain the utility of this norm, for this problem? I mean, just to be extreme, I could define

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Just to clarify Michel's earlier remark, the field norm for the cyclotomics defines the norm in which these vectors are equiangular, and then they will generally **not** be equiangular in the standard norm based on the Hilbert-Schmidt inner product. In the example that he quotes,
$$\|(7\pm 3 \sqrt{

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I worded that badly, since you clearly have explained the sense in which you are using the word. I am wondering, however, how your definition relates to the usual one. Is it a generalization? Or just plain different? For instance, would a SIC be equiangular relative to your definition (using SI

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I am a little confused by this. As I use the term, lines are equiangular if and only if the "trace of pairwise product of (distinct) projectors is constant". You seem to be using the word in a different sense. It might be helpful if you were to explain exactly what is that sense.

To define the complex angle, we used the (cyclotomic) field norm to the power one over the degree of the field, as stated in the introduction. It recovers the particular case of angles for SICs. In this sense "equiangular" means that all pairs of distinct lines make the same angle.

This appears to be an odd and nonstandard definition of "equiangular", unless I'm missing something? Most references I'm aware of, including [Wikipedia][1] and [Renes et al 2004][2] agree that "a set of lines is called equiangular if every pair of lines makes the same angle". For unit vectors (ray

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The trace of pairwise product of (distinct) projectors is not constant. For example, with the state $(0,1,-1,-1,1)$, one gets an equiangular IC-POVM in which the trace is trivalued: it is either $1/16$, or $(7 \pm 3\sqrt{5})/32$. For the state (0,1,i,-i,-1), there are five values of the trace.
We s

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This is why I am confused (it is probably just a reading comprehension error on my part): If the POVM is IC, it must have at least $d^2$ elements. If it is a minimal IC-POVM, it must have exactly $d^2$ elements. But if it is minimal, IC and equiangular, then the angle is fixed by the requirement tha

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Yes, the IC-POVMs under consideration are minimal. The IC-POVM in dimension 5 is equiangular but is also not a SIC. In particular the trace product relation of a SIC is not satisfied. For the equiangular IC-POVM in dimension 7, we have a similar result.

Clarification request: Are all the IC-POVMs in this paper minimal? That is, does the number of elements in each POVM equal the square of the dimension? If so, I am confused about the quoted value of the inner product between projectors for the equiangular IC-POVM in dimension 5.

Hey Noon,

thanks for the feedback! I'm happy to share the code and will send it to you via mail until monday.

Zak, David: thanks! So (I think) this is a relation problem, not a decision problem (or even a partial function). Which is fine -- I'm happier with relation problems than with sampling problems, and the quantum part of Shor's algorithm is solving a relation problem, which is a pretty good pedigre

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Nice work! Are you planning on sharing the code you wrote to run this in the IBM quantum experience system?

However, one should note that I_3322 may be able to do something that this paper doesn't. William's work leaves open the question of whether there are games with infinite-dimensional tensor product strategies but no finite-dimensional ones. Some of us might expect that I_3322 has this property.

Thanks Zak, that's exactly right-- for each instance there is a set of possible solutions. Like in the Bernstein-Vazirani problem, a solution is a bit string. It can't just be a single bit since then we would have the problem you describe, Robin.

You are completely correct that in order to check whether a give output is "correct" for the input, we would require an additional log-depth classical circuit, but this is not how the problem is defined. In particular, for each input there is a set of "accepting" outputs, and we only need to guaran

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Is it okay to be a quantum supremacist? I thought I was, but maybe if it's "tainted" I should reconsider.

On a more serious note... a question for somebody who has read (or written) the paper. If the computation is performed on Poly(n) qubits, and all of them are relevant, and you are only allo

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This is interesting work.

Did the authors happen to make their code available? I think there might be a few other fun experiments to run, and in particular I'd be interested to know how to use this framework for picking a network that does best at _both_ tasks (from the experiments section). That

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I would like to publicly thank the authors for using the term "advantage" instead of the tainted word "supremacy" that makes me cringe every time I hear it.

Also, great result!

Excellent!

A provable separation between analogous quantum and classical circuit classes!

Regarding the pre-2017 state of play, I think experimentalists knew there was a problem for large errors and theorists had known there was a potential problem (as shown by grant proposals for the QCVV program) but nobody had really sat down and thought about how everything behaved for small errors.

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I agree that we pretty much agree on all these points! For the record, though... when you describe the pre-2017 state of play as "...*someone wants to use this theory, but they can't match the sufficient conditions, so they appeal to heuristics to argue that they can use the theory anyway*," this i

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Yes, I did indeed mean that the results of the previous derivations are correct and that predictions from experiments lie within the stated error bounds. To me, it is a different issue if someone derives something with a theoretical guarantee that might have sufficient conditions that are too strong

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I agree with much of your comment. But, the assertion you're disagreeing with isn't really mine. I was trying to summarize the content of the present paper (and 1702.01853, hereafter referred to as [PRYSB]). I'll quote a few passages from the present paper to support my interpretation:

1. "[T

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I disagree with the assertion (1) that the previous theory didn't give "the right answers." The previous theory was sound; no one is claiming that there are any mistakes in any of the proofs. However, there were nonetheless some issues.

The first issue is that the previous analysis of gate-depe

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That's a hard question to answer. I suspect that on any questions that aren't precisely stated (and technical), there's going to be some disagreement between the authors of the two papers. After one read-through, my tentative view is that each of the two papers addresses three topics which are pre

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So what is the deal?

Does this negate all the problems with https://scirate.com/arxiv/1702.01853 ?

Great result!

For those familiar with I_3322, William here gives an example of a nonlocal game exhibiting a behaviour that many of us suspected (but couldn't prove) to be possessed by I_3322.

I feel that while the proliferation of GUNs is unquestionable a good idea, there are many unsupervised networks out there that might use this technology in dangerous ways. Do you think Indifferential-Privacy networks are the answer? Also I fear that the extremist binary networks should be banned ent

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"To get the videos and their labels, we used a YouTube video annotation system, which labels videos with their main topics."
Can anyone explain a bit about this?

A good paper for learning about exRec's is this one https://arxiv.org/abs/quant-ph/0504218. Also, rigorous threshold lower bounds are obtained using an adversarial noise model approach.

Good point, I wish I knew more about ExRecs.

I totally agree -- that part is confusing. It's not clear whether "arbitrary good precision ... using a limited amount of hardware" is supposed to mean that arbitrarily low error rates can be achieved with codes of fixed size (clearly wrong) or just that the resources required to achieve arbitraril

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