The hierarchy, fine-tuning and naturalness problem
from a philosophical perspective
The hierarchy, fine-tuning and naturalness problem from a philosophical perspective
Over the last few decades, the naturalness principle (on one common formulation, the wish that certain parameters in fundamental physics do not require fine-tuning) has been one of the main motivations for physicists to develop alternatives to the Standard Model of elementary particle physics. The goal of this project is to analyze the conceptual origins of the naturalness principle and assess its status as a guiding principle in the construction of theories. In Phase 1 of the project, we identified several points of weakness in the motivations for the naturalness principle and called into question its purported successful applications, such as the prediction of the charm quark mass. In Phase 2, we are going to analyze to what extent and in which form the attitude of physicists towards the naturalness concept has changed in the light of the lack of any conclusive signs for New Physics at the LHC. We further intend to more deeply explore the connection of naturalness to the foundations of renormalization theory and issues of reduction and emergence, and to consider applications of naturalness in other areas of physics, including the cosmological constant problem and the strong-CP problem.
A workshop on naturalness was hosted by the Institute of Theoretical Particle Physics and Cosmology at RWTH Aachen University on Feb 28-Mar 2 2018.
Sahuquillo, M. Á. C. (2019). The charm quark as a naturalness success. Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 68, 51-61.
Harlander R. & Rosaler, J. (2019). Higgs Naturalness and Renormalized Parameters. Foundations of Physics, 49(9), 879-897.
Rosaler, J., & Harlander, R. (2019). Naturalness, Wilsonian renormalization, and “fundamental parameters” in quantum field theory. Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 66, 118-134.