The IA Guide: A Breakdown of Intrinsic Alignment Formalisms

TL;DR

This paper provides a comprehensive overview of the various formalisms, estimators, and modeling approaches used to understand intrinsic alignments in cosmology, serving as a valuable reference for researchers in the field.

Contribution

It compiles and clarifies the diverse notations and concepts in intrinsic alignment research, facilitating better understanding and standardization across studies.

Findings

Summarizes key IA formalisms and estimators

Highlights the importance of IA modeling in weak lensing

Provides a unified reference for IA concepts

Abstract

We summarize common notations and concepts in the field of Intrinsic Alignments (IA). IA refers to physical correlations involving galaxy shapes, galaxy spins, and the underlying cosmic web. Its characterization is an important aspect of modern cosmology, particularly in weak lensing analyses. This resource is both a reference for those already familiar with IA and designed to introduce someone to the field by drawing from various studies and presenting a collection of IA formalisms, estimators, modeling approaches, alternative notations, and useful references.