Agravity up to infinite energy

TL;DR

This paper demonstrates that agravity, a dimensionless gravity theory, can be consistent up to infinite energy by decoupling the conformal mode and approaching conformal gravity, with implications for Higgs mass naturalness.

Contribution

It shows that agravity can be a complete, UV-consistent theory by decoupling the conformal mode and approaching conformal gravity at high energies.

Findings

Agravity can be valid up to infinite energy with large coupling $f_0$.

Decoupling of the conformal mode prevents Landau poles.

Scenarios where the Higgs mass remains natural are identified.

Abstract

The self-interactions of the conformal mode of the graviton are controlled, in dimensionless gravity theories (agravity), by a coupling $f_0$ that is not asymptotically free. We show that, nevertheless, agravity can be a complete theory valid up to infinite energy. When $f_0$ grows to large values, the conformal mode of the graviton decouples from the rest of the theory and does not hit any Landau pole provided that scalars are asymptotically conformally coupled and all other couplings approach fixed points. Then, agravity can flow to conformal gravity at infinite energy. We identify scenarios where the Higgs mass does not receive unnaturally large physical corrections. We also show a useful equivalence between agravity and conformal gravity plus two extra conformally coupled scalars, and give a simpler form for the renormalization group equations of dimensionless couplings as well as of massive parameters in the presence of the most general matter sector.

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