Apparent universality of semiclassical gravity in the far field limit

TL;DR

This paper explores the universality of semiclassical gravity in the far field limit, analyzing quantum effects on scalar fields around stars and black holes, revealing commonalities and differences rooted in specific quantum modes.

Contribution

It demonstrates that differences in quantum corrections near stars and black holes are primarily due to zero-frequency, s-wave modes, highlighting a unified behavior in semiclassical gravity.

Findings

Quantum corrections are dominated by zero-frequency, s-wave modes.

Similarities exist between black holes and stars in quantum behavior.

Differences are linked to infrared effects and specific quantum modes.

Abstract

The universality of semiclassical gravity is investigated by considering the behavior of the quantities < \phi^2 > and < {T^a}_b >, along with quantum corrections to the effective Newtonian potential in the far field limits of static spherically symmetric objects ranging from stars in the weak field Newtonian limit to black holes. For scalar fields it is shown that when differences occur they all result from the behavior of a single mode with zero frequency and angular momentum and are thus due to a combination of infrared and s-wave effects. An intriguing combination of similarities and differences between the extreme cases of a Schwarzschild black hole and a star in the weak field Newtonian limit is explained.