Planckian Interacting Massive Particles as Dark Matter

TL;DR

This paper explores the idea that dark matter could be composed of Planckian Interacting Massive Particles, linking quantum gravity, inflation, and dark matter, and finds that certain mass ranges are already ruled out by cosmological observations.

Contribution

It proposes a minimal dark matter model based on Planck-scale interactions and analyzes its implications for cosmological tensor modes and quantum gravity.

Findings

Masses above 0.01 M_p are ruled out by CMB tensor mode constraints.

Expected detection of tensor modes in upcoming CMB observations.

Connections between quantum gravity, inflation, and dark matter are highlighted.

Abstract

The Standard Model could be self-consistent up to the Planck scale according to the present measurements of the Higgs mass and top quark Yukawa coupling. It is therefore possible that new physics is only coupled to the Standard Model through Planck suppressed higher dimensional operators. In this case the WIMP miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian Interacting Massive Particle, we show that the most natural mass larger than $0.01\,\textrm{M}_p$ is already ruled out by the absence of tensor modes in the CMB. This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the KK graviton mode as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar properties of this type of dark matter candidate. This paradigm therefore leads to a subtle connection between quantum gravity, the physics of primordial inflation, and the nature of dark matter.