Recent content by jenga42

I wasn't quite sure where to put this - hopefully it's in the right place! I am a PhD student and am applying for a fellowship which includes writing a "Lay Report". This report has to be understood by someone who has recently taken physics at A-level (UK) ... the trouble is, I don't know...

Normal trace is equivalent to the sum of the eigenvalues (or diagonal elements) of a matrix. Partial trace acts only on part of the system, so for a density matrix.. say it's a pure state but entangled, \rho_{AB}=\frac{1}{2}(|01\rangle +|10\rangle )(\langle 01|+\langle 10 |) The partial...

Ok... so I know that it isn't cyclic now ... just by picking a random example, but if anyone knows the reason why it's not cyclic, and has a general proof as to why it's not, I'd be very grateful to hear it! Thanks.

Hello, I know trace is usually cyclic, but is partial trace cyclic too? Why? Thanks! Jenga

I've just had a thought, can I just say that as f(x)>0, then it cannot change the direction of the inequality, hence if a(x)<b(x) , then multiplying both sides by f(x), we find f(x)a(x)<f(x)b(x) and therefore \int_{x_i}^{x_f} f(x)a(x) dx < \int_{x_i}^{x_f} f(x)b(x) dx ? This is...

Hi, Thanks for replying! I didn't know I could type the equations! Just to clarify, I meant if a(x)<b(x), can I say \int_{x_i}^{x_f} f(x) a(x) dx < \int_{x_i}^{x_f} f(x) b(x) dx where f(x)>0. I'd like to know if there is a general theorem for this to be true? ...I think that...

Hello, I'm trying to figure out if this is true - any help would be greatly appreciated! If a(x) < b(x) between the values x_i and x_f then is the following also true?... int_{x_i}^{x_f} dx f(x) a(x) < int_{x_i}^{x_f} dx f(x) b(x) where f(x)>0 for all x. ...I think it is true...

Thanks for replying... I should have written "if f(z) doesn't have any singularities, can it be any function?" .. can it? Thanks

I'm trying to do a trigonometric type contour integration... one with limits of integration between -Pi and Pi. Is there a rule about what the integrand has to look like? Eg can I do this (I've converted it into z's): int( f(z)/( (z-z1)^2 (z-z2)^2 ) ,z) ...can f(z) be any function...

Actually I tried it just incase, and it works! ...Though I'm not really sure why! - Does isosurface estimate the values corresponding to i, j and k where F(i,j,k)=1?- Thank you!

Hi, Thanks for your reply. Unfortunately, I don't think the isosurface function will work in my case as although I want to plot when F(i,j,k)=1, the function never precisely equals 1: I'll need to plot something like 0.99<F(i,j,k)<1.01. Any other suggestions would be greatly...

Hi, I'm trying to plot a 3d graph of when a function, F(i,j,k) = 1 ...I want to plot 3 variables that correspond to the i j and k against each other when the function equals 1. ...I've tried using surf but it tells me that its Z component needs to be a matrix, not a scalar or vector.. but...