Recent content by Nod

The boundary conditions are already applied to the nanotubes. I was given a hint that I need to open up the nanotube and "map" it: just like the mapping of the round Earth is made on a flat surface. But even in this case I saw that there are manu ways of doing it. Should I preserve the...

Hi everyone! I'm trying to solve the following problem: given the charge densities of carbon nanotubes and graphene, the charge density difference of 2 systems must be found. So I need to unfold in some way the nanotube and compare it charge density with the graphene's one. But how this...

Thank you for explanation! Now I get where the signs come from :)

I also thought like this, but still I have doubts: If I replace ##p## with ##-p##, then instead of ##\displaystyle{\not} p = γ_μ p^μ = γ_0 p^0 +γ_i p^i## I'll have ##\displaystyle{\not}p = γ_μ p^μ = γ_0 p^0 -γ_i p^i##. But the last equation is not equal to ##-\displaystyle{\not}p## , because...

Hi everyone! I'm having a problem with calculating the fermionic propagator for the quantized Dirac field as in the attached pdf. The step that puzzles me is the one performed at 5.27 to get 5.28. Why can I take outside (iγ⋅∂+m) if the second term in 5.27 has (iγ⋅∂-m)? And why there's a...