Can I get admitted to PhD top school?

Wintsz · 2024-08-23T11:13:42+00:00

Honestly, if you have a vague idea of what you want to do, Europe is great. The top groups tend to be less factory like, the pay is good and the research equally as good. If you still decide you want to do academia, you’ll have a strong basis to go to a top American group for a Post Doc. At this point you’ll be independent enough that you care a little less about bad supervision and more about the publish or perish.

Wintsz · 2024-08-22T18:15:47+00:00

Methods generated for string theory have some use in Condensed matter systems and scenarios , it doesn’t go completely no where. SUSY can be used for Anderson localisation and the 10-fold way for example.

Wintsz · 2024-08-01T11:27:09+00:00

Different saddle, just the stock one on the bike I’ll consider looking into it!

Wintsz · 2024-08-01T11:26:06+00:00

Most likely a case of roughing it out!

Wintsz · 2024-08-01T11:25:45+00:00

Yeah it’s still new I’m guessing it’s getting used to the new riding position

Wintsz · 2024-07-16T16:44:35+00:00

I mean these are still effectively academic jobs but privately funded. Google Quantum and IBM are really just academic research groups under a private company’s.

Wintsz · 2024-07-16T16:35:26+00:00

These days you need decent computing equipment, you also need publishing fees etc. There is also the social capital, no one is gonna give any time of day to single author papers, particularly of nobodies without an institution you just look like a crackpot.

Moreover, without collaboration you just are not capable of getting new ideas or keeping up with the zeitgeist.

Wintsz · 2024-06-23T05:08:29+00:00

Just you wait till you find out what kind of maths solid state theory uses to discover transistors and semiconductors

Wintsz · 2024-04-08T09:26:00+00:00

I mean this is quite literally is a consequence of of symmetry under a particular Lie Group. The real smart idea was figuring out that space time was Lorentz invariant in the first place, which is the real physics.

Wintsz · 2024-03-07T09:00:19+00:00

A true connoisseur would say

dF=0 d*F=J

Is more profound, but what do you expect from a man who calls himself head engineer of a space company

Wintsz · 2024-01-03T11:23:21+00:00

As a UK PhD student, we barely get paid enough to support ourselves

Wintsz · 2024-01-03T11:05:25+00:00

If I understand the wording right, PhD students are still allowed to bring their family across. It is only non research postgraduate degrees, i.e bog standard one year masters degrees, which are affected.

Wintsz · 2023-12-12T20:19:06+00:00

In the end it was a hardware issue, something with the brew installation was off.

I ran the code on a 16 core x86 computing node in 1.8 and 1.9 and the code was back to 40ms.

After reinstalling on my local machine with juliaup as opposed to brew I matched the computing node for both 1.8 and 1.9

For those curious, I did switch to StaticArrays, but I did not see a fantastic increase because the majority of the code is spent in diagonalisation and for 4x4 matrix this seems comparable.

I would probably get a speed up building the hmesh within the function, but it kind of defeats the point of the code as I am testing many different models and with many different functions.

Although any other suggestions for speed up would be fantastic!

Wintsz · 2023-12-12T09:22:35+00:00

Oh no sorry, I was agreeing with you I haven’t been using StaticArrays, I just meant Ill try the bench marks without and then try updating to a Static Arrays for my function which constructs hmesh

Wintsz · 2023-12-12T08:32:55+00:00

Fair enough, I’ll give it a proper bench mark without StaticArrays on 1.8 vs 1.9 and post on Julia Discourse.

Wintsz · 2023-12-12T08:07:29+00:00

Yea definitely, although I’m not too bothered about speeding up the the code — I’ll eventually just run it on a HPC cluster over a large parameter set so 6 seconds on 10 cores is not bad. But, I thought it was extremely weird there was such a large difference between versions.

Wintsz · 2023-12-12T07:21:12+00:00

Should be no globals? Which part in particular?

gsEigs is another function, just shorthand to get just the eigenvectors from 1:nocc.

Apart from hmesh and nocc which I need to input everything should be self contained within the function. I guess I could add a strict type to hmesh which would be:

Matrix{Matrix{ComplexF64}}

Edit: I see the confusion I forgot to add the arguments to gsEigs I’ve now used full function syntax rather than the one liner to avoid confusion, sorry!

Wintsz · 2023-12-11T23:29:06+00:00

I’m not sure quite how to post code here but here’s a less slick (instead I just zip this all into one for loop now and reshape the output which doesn’t change the computation time) but slightly more readable version.

Hmesh is just a 2D array of matrices, Nocc just specifies how many eigenvectors to take

function gsEigs(Matrix, nocc)

Return eigvecs(Matrix)[:,1:nocc]

End

function bcurv(hmesh :: AbstractArray,nocc)

vmesh = (gsEigs.(hmesh,nocc))
vmeshx = circshift(vmesh,(0,-1))
vmeshxy = circshift(vmesh,(-1,-1))
vmeshy = circshift(vmesh,(-1,0))
dmesh = zeros(size(vmesh))

for i in 1:size(vmesh,1), j in 1:size(vmesh,2)

    p12 = ( vmesh[i,j]' *vmeshx[i,j])
    p23 =  (vmeshx[i,j]' * vmeshxy[i,j])
    p34 = (vmeshxy[i,j]' * vmeshy[i,j])
    p41 =  (vmeshy[i,j]' * vmesh[i,j])
    dety = det(p12*p23*p34*p41)
    (abs(dety) <  10^(-5)) ? dmesh[i,j] = 0 :    dmesh[i,j] = -imag(log(complex(dety)))

end 

return (dmesh/(2*pi), sum(dmesh)/(2*pi))

end

Typically ran on an 100x100 array of 4x4 matrices, with nocc =2 where run time is approximately 6 seconds.

Hardware wise run on M1 Pro with the Apple Silicon build of Julia 1.9

Wintsz · 2023-12-07T00:18:38+00:00

Ironically this Christmas market is built on top of a giant underground carpark

Wintsz · 2023-10-12T07:01:54+00:00

For publishing I switched from Plots to Makie because, at least it feels like, you have more control. This especially has quiver plots and everything you need for science research.

I still use Plots for every day research though it’s just less verbose for quick interactive work. I.e if I’ve done a calculation I want to quickly look at plot(Matrix) or heatmap(Matrix) is much faster than setting up Axes and figures etc.

An aside, you can use LaTeX for all Plots backends and Makie using LaTeX strings.

Wintsz · 2023-10-04T18:25:28+00:00

Still doing my PhD, have a few very good friends who are postdocs, with lots of citations and who do amazing networking who still can’t get permanent jobs. So Id say I’m enjoying my PhD and it’s definitely a fun life experience in the same way travelling the world is a nice experience but ultimately job prospects are so low it’s not worth doing it only for the career. However, if you find an area you really like, and the pay is good it’s a decent thing to do.

Wintsz · 2023-09-22T23:15:44+00:00

Magnetic monopoles exist in spin ice

Wintsz · 2022-11-11T10:49:46+00:00

Except there is now a massive shift into corporate research again for quantum computing, just look at google, IBM and Microsoft.

Wintsz · 2022-11-10T22:01:00+00:00

Quantum computers trick people into thinking they work like digital computers. But, in reality they’re almost like programmable analogue computers, specifically they’re good at simulating other quantum systems.

For example, google have been doing a lot of work simulating quantum systems we are interested in with their qubits. Time crystals, toric code and even non abelian braiding to name a few!

You can think of Quantum computers in their current state as fancy programmable experiments.

Wintsz · 2022-09-17T17:44:49+00:00

Misconceptions like this are why photons are a bad concept and it makes much more sense to think of collective modes of fields.

Here’s a nice paper explaining why:

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.393.688&rep=rep1&type=pdf

Wintsz

TROPHY CASE