Entries by Bill Hobba

Some Useful Integrals In Quantum Field Theory

In my paper on renormalisation I mentioned what most who have studied calculations in Quantum Field Theory find, its rather complicated and mind numbing. I am not sure doing these is that illuminating of anything, but every now and then you gotta to do, what you gotta to do, so I would like to go […]

Why Renormalisation Needs a Cutoff

This is a follow on from my paper explaining renormalisation. A question was raised – why exactly do we need a cut-off. There is a deep reason to do with dimensional analysis, and the power series expansion used in perturbation theory. Along the way we will see renormalisation in a more general setting, and exactly […]

Renormalisation Made Easy

What Is The Issue With Renormalisation If you have an interest in physics you have likely come across renormalisation before, although what it really is would probably have not been explained.  Instead you would read Dirac never accepted it, Feynman called it a ‘dippy process’, and if you look under a quantum theorists rug you […]