# Forays into the dark side of the swamp

## TL;DR

This paper explores how a quintessence potential, motivated by swampland conjectures, can produce observable effects in particle physics and cosmology, including dark matter interactions, freeze-in production, and electroweak vacuum stability.

## Contribution

It introduces a framework linking time-varying quintessence fields to multiple phenomenological signatures, expanding the understanding of dark energy's impact on particle physics.

## Key findings

- Time-varying dark matter self-interactions reconcile small-scale structure issues with cluster constraints.
- Kinetic mixing variation affects freeze-in dark matter production during radiation era.
- Quintessence influences electroweak symmetry restoration and vacuum lifetime through Higgs mass modifications.

## Abstract

Motivated by the swampland conjectures, we study cosmological signatures of a quintessence potential which induces time variation in the low energy effective field theory. After deriving the evolution of the quintessence field, we illustrate its possible ramifications by exploring putative imprints in a number of directions of particle phenomenology. We first show that a dark matter self-interaction rate increasing with time gives a novel way of reconciling the large self interactions required to address small scale structure issues with the constraint coming from clusters. Next, we study the effects of kinetic mixing variation during the radiation dominated era on freeze-in dark matter production. Last, we elucidate quintessence effects on the restoration of the electroweak symmetry at finite temperature and the lifetime of the electroweak vacuum through a modification of the effective Higgs mass and quartic coupling.