#fieldtheory — Public Fediverse posts on home.social

#paperOfTheDay "Theres' plenty of room in the middle: The unsung revolution of the renormalization group" from 2023 is a meta-article to commemorate 50 years of the #renormalization group in memory of one of its pioneers, Michael E. Fisher.
First of all, this article is a masterly and dense historical overview, basically every single reference in it is a breakthrough article worth reading. This being said, the article builds upon "Fisher's least cited article". There, Fisher introduces the thesis, which is elaborated in the present article, that almost all interesting #physics happens in the "middle"; concretely in the realm of collective phenomena and effective #fieldTheory governed by the renormalization group.
The present article discusses various examples, each with a provocative title, for example the BCS theory of superconductivity (famously a pure quantum effect) under the slogan that quantum mechanics is really not needed for condensed matter physics. The reasoning is: Such effects are described by effective field theories and "minimal models" with certain "asymptotic" properties (this is discussed in detail), in concrete cases these models can be derived from quantum mechanics, but this derivation does not really add anything to the practical understanding. At the same time, one can often obtain them from thermodynamic considerations alone, regardless of any more fundamental theory.
The article ends with the standard model of elementary particle physics, with the same thesis: One can view this as "just some EFT", which is valid as a very accurate model to describe observations, regardless of whether it is "fundamental"
. https://arxiv.org/abs/2306.06020v1