Naturalness, Extra-Empirical Theory Assessments, and the Implications of Skepticism

TL;DR

This paper critically examines the concept of naturalness in theory assessment, discussing its limitations, skepticism, and the implications of extra-empirical evaluations, ultimately advocating for a moderate stance.

Contribution

It provides a comprehensive critique of naturalness and extra-empirical assessments, proposing a balanced moderate position amidst conflicting viewpoints.

Findings

Naturalness remains a debated concept with no consensus.

Skepticism towards extra-empirical theory assessments is justified.

A moderate naturalness position is identified as most viable.

Abstract

Naturalness is an extra-empirical quality that aims to assess plausibility of a theory. Finetuning measures are often deputized to quantify the task. However, knowing statistical distributions on parameters appears necessary. Such meta-theories are not known yet. A critical discussion of these issues is presented, including their possible resolutions in fixed points. Both agreement to and skepticism of naturalness's utility remains credible, as is skepticism to any extra-empirical theory assessment (SEETA) that claims to identify "more correct" theories that are equally empirically adequate. The severe implications of SEETA are set forward in some detail. We conclude with a summary and discussion of the viability of three main viewpoints toward naturalness and fine-tuning, where the "moderate naturalness position" is suggested to be most appealing, not suffering from the disquietudes of the extreme pro- and anti-naturalness positions.