Infinities as a measure of our ignorance

TL;DR

This paper discusses how infinities in quantum gravity are viewed as signs of our limited understanding, with loop quantum gravity removing certain infinities through quantization and the cosmological constant addressing others.

Contribution

It offers a perspective that infinities in physics indicate the need for theory improvement rather than fundamental aspects, highlighting loop quantum gravity's approach.

Findings

Infinities in cosmology are resolved by spacetime quanta.

The cosmological constant helps tame infinities in covariant loop quantum gravity.

Infinities reflect our limited knowledge, not fundamental nature.

Abstract

The quantization of gravity offers a solution to the presence of singularities in cosmology. Infinities are removed because of the existence of finite quanta of spacetime. This is one of the most important prediction of Loop Quantum Gravity. But treating gravity on the same footing as the other quantum field theories introduces a different kind of infinities: the ones from the renormalization procedure. In the covariant formulation of Loop Quantum Gravity (Spinfoam) this kind of infinities are tamed by the presence of the cosmological constant. These two results are guided by a specific perspective on the appearance of infinity in physics: this is just interpreted as a signpost that the theory should be improved. It arises from our limited knowledge, and not as a fundamental fact of nature.