Jeans Analysis of Bok globules in $f(R)$ gravity

TL;DR

This paper investigates how $f(R)$ gravity modifies the Jeans criterion for star formation in molecular clouds, providing a method to test such theories through their impact on collapse limits and comparing predictions with observations of Bok globules.

Contribution

It introduces a novel approach to test $f(R)$ gravity models by analyzing their effects on Jeans mass and star formation, including the derivation of asymptotic Jeans masses in these theories.

Findings

Viable $f(R)$ models can facilitate star formation by lowering Jeans mass thresholds.

The study compares $f(R)$ modified Jeans masses with those in standard gravity.

Bok globules are effective for testing different $f(R)$ gravity models.

Abstract

We examine the effects of $f(R)$ gravity on Jeans analysis of collapsing dust clouds. We provide a method for testing modified gravity models by their effects on star formation as the presence of $f(R)$ gravity is found to modify the limit for collapse. In this analysis we add perturbations to a de Sitter background. Depending on the characteristics of a chosen $f(R)$ model, the appearance of new limits is possible. The physicality of these limits is further examined. We find the asymptotic Jeans masses for $f(R)$ theories compared to standard Jeans mass. Through this ratio, the effects of the $f(R)$ modified Jeans mass for viable theories are examined in molecular clouds. Bok globules have a mass range comparable to Jeans masses in question and are therefore used for comparing different $f(R)$ models. Viable theories are found to assist in star formation.