# CR-invariance of the Steinness index

## TL;DR

This paper characterizes the Diederich-Fornaess and Steinness indices using a special 1-form and proves their invariance under CR-diffeomorphisms, advancing understanding of CR-invariant properties in complex analysis.

## Contribution

It introduces the D'Angelo 1-form to characterize the indices and establishes their invariance under CR-diffeomorphisms, providing new insights into CR-invariant geometric properties.

## Key findings

- Diederich-Fornaess and Steinness indices characterized by D'Angelo 1-form
- Proved invariance of these indices under CR-diffeomorphisms
- Established CR-invariance of D'Angelo 1-forms

## Abstract

We characterize the Diederich-Fornaess index and the Steinness index in terms of a special 1-form, which we call D'Angelo 1-form. We then prove that the Diederich-Fornaess and Steinness indices are invariant under CR-diffeomorphisms by showing CR-invariance of D'Angelo 1-forms.