Once again, the day started with lectures at DAMTP. I attended three lectures in a row, all in the same lecture theatre. First up, was Symmetries, Fields and Particles. This subject is something that covers in more detail things we learnt in Gauge Field Theory last year. We covered tangent spaces and how to determine the Lie Algebra for a given group. This is something that I kind of knew how to do, but couldn’t really explain or do independently, so it was really good to go over it a lot more slowly. For those who are not theoretical physicists, suppose you have some theory of a particle interaction which satisfies certain symmetry properties. Those symmetry properties are typically sufficient to specify a number of physical properties about that particular interaction.
Second was Cosmology; a hand-wavy lecture on inflation. This is a presently-hypothetical period of the universe where the structure of space-time expanded faster than the speed of light (which is okay, so long as the particles themselves in the space time don’t move faster than light). It solves a number of problems with the Big Bang, but raises additional ones too.
Finally, was Quantum Field Theory. I hadn’t attended this lecture stream before, and my reasoning was confirmed when it was almost word for word revision of Quantum Field Theory back in Adelaide. This isn’t surprising, as the textbook for this course is so universally used so most courses are rather similar.
I returned to the office for the afternoon. I thought of a way to show that my data had been fixed. I plotted out the neutrino flux as a function of the cross section in comparison to a previous work
The red dots are the previous work. The black dots on the left are what I originally had, certain points aren’t consistent, and the graph isn’t smooth (it should be). The blue dots on the right are the fixed data. The graph is now smooth, indicating that everything has been fixed correctly. I sent this around, and we are now mostly satisfied and ready to post, but there is just one more thing we want to check first.
I came back to the college for dinner, roast pork, and headed out to football training at the CASS centre. We warmed up and divided into three groups. Two played 7-a-side on the half-court. The third group were delayed from training on the larger pitch by another group, so played a bit of football-tennis with a nearby tennis net. Shortly after, I had some goalkeeper practice, and rotated into some 7-a-side as well.