6,262 reputation
1943
bio website jfitzsimons.org
location Singapore, Singapore
age 32
visits member for 4 years, 1 month
seen Nov 17 at 5:14

I have just moved to the Center for Quantum Technologies in Singapore, after spending the last 3 years as a Merton College JRF in Theoretical Physics and a Senior Research Fellow in Oxford University Department of Materials. My research focuses largely on theoretical aspects of quantum information processing. In particular I am interested in spin networks, measurement based computation, cryptography and computational complexity.


Sep
24
comment The Role of Rigor
From my perspective, at least, this seems to be an interesting question phrased in a way that can have reasonably objective answers, so I don't see why it should be closed.
Sep
24
comment Post-doc advice for a low publication grad student
@RobertFilter: It was 5 years ago for me, so not that recent, but the memories are still fresh.
Sep
24
comment Post-doc advice for a low publication grad student
@Robert: There are people on here with more experience than me, so there are probably more authoritative answers out there.
Sep
24
comment Models of neutrinos consistent with OPERA's results
@LubošMotl: I'm afraid I haven't had a chance to really dig into the two papers yet. It seemed like it might be ok by a rough back of the envelope calculation, given how big the error bars on previous results are, but I certainly wouldn't swear by it.
Sep
24
comment Models of neutrinos consistent with OPERA's results
Yes, sorry, I should have been clearer on that. I just thought it was interesting in the context of the energy dependence loophole.
Sep
23
comment Models of neutrinos consistent with OPERA's results
Thanks Lubos for the detailed answer. For what it's worth, I've also just come across arXiv:0805.0253 by John Ellis and others which examines energy dependent velocities, and doesn't seem to be entirely incompatible with the current results. Thanks for a great answer, and welcome to the site.
Sep
23
comment Models of neutrinos consistent with OPERA's results
@Michael: What in particular? The superluminal bit? Yep, it's crazy, and everyone seems to be rightly skeptical, but who knows? It's unlikely we will know for sure until other experiments either replicate or fail to replicate the results. Even the OPERA team seems skeptical of their own results.
Sep
23
comment Models of neutrinos consistent with OPERA's results
@Slaviks: No. I mean that the bounds are further away from $c$ for increasing energy, and this could be explained by a monotonic function, which seems more natural than a non-monotonic one. I guess you are refering to the 3GeV data point, but here the error bars are loose, so it could easily be below the 17GeV velocity while still being within the error bars. But, frankly I'd be interested in any models which fit all 4 points relatively well.
Sep
22
comment What do theoretical physicists need from computer scientists?
@Aaron: You know physicists have been using randomized algorithms since the 40s?
Sep
22
comment Vasiliev Higher Spin Theory and Supersymmetry
You get +1 from me and the bounty. Welcome to the site!
Sep
21
comment What do theoretical physicists need from computer scientists?
@LoganMaingi: I think you still miss my point. Saying "we want better simulation algorithms" is an entirely reasonable thing to ask for. As I said, I only used matrix multiplication as an example to illustrate the difference between better algorithms and faster code.
Sep
21
comment What do theoretical physicists need from computer scientists?
I had in mind your comment to Peter where you said "While I can't disagree that it would be nice to speed these up, considering the amount of work that was put into optimizing every aspect of the particular codes I worked with (by professional programmers as well as physicists), I'd be surprised if they could be sped up more than linearly." It seemed to me that you were focused on optimizing your programme, while he was talking about better algorithms.
Sep
21
comment What do theoretical physicists need from computer scientists?
@LoganMaingi: I wasn't talking about matrix multiplication. It was simply an example of the difference between a better algorithm and optimized code.
Sep
21
comment What do theoretical physicists need from computer scientists?
@LoganMaingi: Finding a better algorithm for a problem goes way beyond optimizing code for a specific algorithm. An example of this is matrix multiplication: No matter how well you implement the multiplication you learned in school or college it takes $O(n^3)$. However there are better algorithms which give a scaling of $O(n^k)$ for $k<3$, which you would never get by trying to optimize the implementation of naive multiplication. See en.wikipedia.org/wiki/…
Sep
21
comment What do theoretical physicists need from computer scientists?
@LoganMaingi: Perhaps that quote coupled with my previous interactions with Aaron have coloured my interpretation of what he was asking.
Sep
21
comment What do theoretical physicists need from computer scientists?
@Logan: He specifically says "Are there theoretical issues of combinatorics, algorithm analysis, that physics needs a theoretical computer scientist to solve?"
Sep
21
comment Visualization of 1D spin chain wave fuction
@PiotrMigdal: It seems to me that you want references to papers that specifically discuss how to draw such plots, but I doubt these really exist. We have excellent measures of correlation (i.e. concurrence, etc) between sites, but how you plot them is up to you. For two-site correlations, a 2D image or surface plot in 3D of the value of the correlation (for whatever metric you choose) is the natural choice.
Sep
20
comment What do theoretical physicists need from computer scientists?
@Kaveh: Yes, I know. I simply meant at a high level the mathematics tends to be different.
Sep
20
comment Post-doc advice for a low publication grad student
@Slaviks: In this case, I would think that experience is necessary to give a good answer to the question.
Sep
20
comment Why can't noncontextual ontological theories have stronger correlations than commutative theories?
@Mateus: I think I did understand, which is what my last paragraph attempts to address.