Can be thought as being produced from gluon-gluon lines of the Feynman diagrams of quantum chromodynamics. This is in contrast to quantum electrodynamics, in which there are no photon-photon vertices, because the photon does not have charge unlike gluons.
TODO what is the point of them? Why not just sum over every index that appears twice, regardless of where it is, as mentioned at: www.maths.cam.ac.uk/postgrad/part-iii/files/misc/index-notation.pdf.
Those in indices on bottom are called contravariant vectors.
It is possible to change between them by Raising and lowering indices.
The values are different only when the metric signature matrix is different from the identity matrix.
Rifleman's Creed from Full Metal Jacket
. Source. This is possibly where Ciro Santilli first came about this. But not sure, it was too long ago during good old University of São Paulo days.One of the best in the world, but you need to know how to find real restaurants if you are not in China.
But worry not, Ciro Santilli has got you covered: github.com/cirosantilli/china-dictatorship/restaurants
- www.youtube.com/channel/UC54SLBnD5k5U3Q6N__UjbAw Chinese Cooking Demystified. Possibly the best YouTube channel at explaining how to make key Chinese dishes and sauces in English.
Some stuff at: cirosantilli.com/china-dictatorship/#the-best-chinese-food but that is bound to die one guesses.
Appears in the Schrödinger equation.
There are unlisted articles, also show them or only show them.