# A simplification of "Effective quasimorphisms on right-angled Artin groups"

## TL;DR

This paper simplifies the proof of a key result in the study of quasimorphisms on RAAG-like groups acting on CAT(0) cube complexes, making the argument more accessible and concise.

## Contribution

It provides a shorter, more straightforward proof that quasimorphisms on RAAG-like groups have a uniform defect and specific value properties, removing the need for complex tools.

## Key findings

- Quasimorphisms on RAAG-like groups have a uniform defect of 12.
- Hyperbolic elements in RAAG-like groups have stable commutator length at least 1/24.
- The simplified proof avoids technical tools like essential characteristic sets and equivariant Euclidean embeddings.

## Abstract

This paper presents a simplification of the main argument in "Effective quasimorphisms on right-angled Artin groups" by Fern\'os, Forester and Tao. Their article introduces a family of quasimorphisms on a certain class of groups (called RAAG-like) acting on CAT(0) cube complexes. They show that these have uniform defect of $12$ and take the value of at least $1$ on a chosen element. With the Bavard Duality they conclude that hyperbolic elements of RAAG-like groups have stable commutator length of at least $1/24$. Their proof that the quasimorphisms take the value $1$ is quite technical and relies on some tools they introduce: the essential characteristic set and equivariant Euclidean embeddings. Here it is shown that this is unnecessary and a much shorter proof is given. This was originally part of my master thesis "Stable commutator length gap in RAAG-like groups" supervised by Alessandra Iozzi at ETH Z\"urich.