A pedagogical explanation for the non-renormalizability of gravity

TL;DR

This paper provides an intuitive, pedagogical explanation for why gravity cannot be renormalized in quantum field theory, emphasizing black-hole dominance at high energies rather than traditional perturbative arguments.

Contribution

It offers a clear, non-technical argument highlighting black-hole effects as the reason for gravity's non-renormalizability, differing from standard perturbative approaches.

Findings

Black-hole dominance explains high-energy behavior of gravity.

Gravity's non-renormalizability is linked to black-hole physics.

The argument is accessible and pedagogical, suitable for educational purposes.

Abstract

We present a short and intuitive argument explaining why gravity is non-renormalizable. The argument is based on black-hole domination of the high energy spectrum of gravity and not on the standard perturbative irrelevance of the gravitational coupling. This is a pedagogical note, containing textbook material that is widely appreciated by experts and is by no means original.