Quantum gravity effects on compact star cores

TL;DR

This paper investigates how quantum gravity, modeled via the generalized uncertainty principle, influences the internal structure and mass limits of compact stars like neutron and quark stars.

Contribution

It introduces a novel analysis of quantum gravity effects on compact star cores using GUP and TOV equations, revealing significant deviations from classical gravity predictions.

Findings

Quantum gravity affects the metric components near star centers.

The mass limit of neutron stars constrains the quantum gravity parameter .

Quantum effects and nuclear interactions yield similar neutron star mass limits.

Abstract

Using the Tolman-Oppenheimer-Volkoff equation and the equation of state of zero temperature ultra-relativistic Fermi gas based on generalized uncertainty principle (GUP), the quantum gravitational effects on the cores of compact stars are discussed. Our results show that ${2m(r)}/ {r}$ varies with $r$. Quantum gravity plays an important role in the region $ r\sim 10^3 r_0$, where $r_0\sim \beta_0 l_p $, $l_p$ is the Planck length and $\beta_0$ is a dimensionless parameter accounting for quantum gravity effects. Furthermore, near the center of compact stars, we find that the metric components are $g_{tt}\sim r^4$ and $g_{rr}=[1-{r}^2/(6r_0^2)]^{-1}$. All these effects are different from those obtained from classical gravity. These results can be applied to neutron stars or denser ones like quark stars. The observed masses of neutron stars ($\leq 2M_\odot$) indicate that $\beta_0$ can not exceed $10^{37}$, not as good as the upper bound $\beta_0<10^{34}$ from simple electroweak consideration. This means that incorporating either quantum gravity effects or nuclear interactions, one obtains almost the same mass limits of neutron stars.