Recent content by eherrtelle59

I'm having trouble finding the correct approach to my (fairly simple) example. Let's say I have months of data for log-in times of a certain website. The data has been selected and cleaned such that I have a list of Date_Time for each log-in. Now, suppose I wanted to predict the log-ins...

In case I'm being to obscure above, let's just work with QED vs. QCD. How do you know these theories are marginally (ir)relevant as opposed to (ir)relevant? Thanks

Actually, I'm wrong above. At lower and lower energy scales M, g becomes larger and larger and therefore relevant. Why is it marginally relevant instead of relevant?

Ok, I'm having some conceptual difficulty here. When discussing beta functions and the relation how these differential equations flow, I still don't quite get the difference between relevant vs. marginally relevant and irrelevant vs. marginally irrelevant. For instance, take the β function...

Hi. 1. Can anyone definitively tell me what the dimension formula for the classical Lie algebras? For example, I know for SO(2n) or D_n, the dimension formula is SO(N)--> (N*(N-1))/2 E.g. SO(8) is 8*7/2 = 28. Ok, so what about SU(N+1) i.e. A_n, SO(2n+1) i.e. B_N and Sp(n) i.e...

That is, using your equation ax- y= bx a=-1, b=(x-1/4)

Typo on my part. we get for the "b value" an equation -v_1-v_2 = (x-1/4)*v_1 This is -v_2 =(x+3/4)*v_1

I'm sorry everyone, that should be multiply by \begin{pmatrix} (1-4c/3)v_1\\ (1-4c/3)v_2\\ \end{pmatrix} which does indeed give the right answer, (c/3)*v_1 = (c/3 -1)*v_2 Sorry for wasting everyone's time, I've finally got it now. Thank you!

"but the fact that you have a scaling of e1= a scaling of e2 seems pretty suspicious" When finding eigenvectors I always get equations like this.

"The clearly negative eigenvalue being allegedly positive is the first thing that struck me as odd, but not really a big deal in the grand scheme of things" That's a typo on my part. λ_2 should be negative i.e. -c<0 "is it supposed to be ( (c/3-1), 4/3)?" Yes To show explicitly what...

Ok, this is starting to come back to me, but I'm stuck again Homework Statement M=\begin{bmatrix} (1-\frac{4}{3}) & 0 \\ -\frac{c}{3} & -c \\ \end{bmatrix} Find eigenvectors and eigenvalues. Homework Equations The Attempt at a Solution Eigenvalues are λ_1=...

i.e. b-a is 1-(-1/4)=3/4, right?

This makes sense, but according to what I have here, the eigenvector should be λ_2 = <-1 x+ (3/4)> This is assuming x-(1/4) > 0. Would that make a difference or is what I have a typo?

Um...yes... So, (-σ-λ)e_1 +σ e_2 =0 Looking at this and getting (σ+λ)e_1 =σ e_2, I would think the eigenvector is (σ+λ σ) not (σ+λ σ).

I thought I would ask this in the homework section. Homework Statement I should be able to write down the eigenvectors and eigenvalues of diagonal and triangular matrices on sight. M = \begin{bmatrix} 1 &0 \\[0.3em] 0 & x \\[0.3em]...